Repurposing spent biomass of vetiver grass used for stormwater treatment to generate biochar and ethanol

Stormwater pollution is a key factor contributing to water quality degradation, posing substantial environmental and human health risks. Although stormwater retention ponds, also referred to as wet ponds, are commonly implemented to alleviate stormwater challenges by reducing peak flow and removing suspended solids, their effectiveness in removing heavy metals and nutrients is limited. This study evaluated the performance of floating treatment platforms (FTPs) featuring vetiver grass (Chrysopogon zizanioides), a non-invasive, nutrient- and metal-accumulating perennial grass, in removing heavy metals (Cu, Pb, and Zn) and nutrients (P and N) in stormwater retention ponds. Furthermore, the potential for utilizing the spent vetiver biomass for generating biochar and bioethanol was investigated. The study was conducted in a greenhouse setup under simulated wet and dry weather conditions using pond water collected from a retention pond in Stafford Township, New Jersey, USA. Two FTPs with vetiver (vegetated FTPs) were compared with two FTPs without vetiver (non-vegetated FTPs), which served as controls. Results showed that the removal of heavy metals and nutrients by the FTPs with vetiver was significantly higher (p < 0.05) than the FTPs without vetiver. Notably, vetiver showed resilience to stormwater pollutants and hydroponic conditions, displaying no visible stress symptoms. The biochar and bioethanol generated from the spent vetiver exhibited desirable yield and quality, without raising concerns regarding pollutant leaching, indicated by very low TCLP and SPLP concentrations. This study provides compelling evidence that the implementation of vetiver-based FTPs offers a cost-effective and environment-friendly solution for mitigating stormwater pollution in retention ponds. Furthermore, the utilization of vetiver biomass for biofuel and biochar production supports clean production and fostering circular economy efforts.

Vetiver grass cleans up arsenic contaminated field for subsequent safe cultivation of rice with low arsenic in grains: A two year field study

The presence of high concentrations of arsenic (As) in agricultural soils and its subsequent accumulation in rice crop is a serious issue threatening sustainability of agriculture and human health. In the present work, remediation of As contaminated field in Nadia, West Bengal, India was done through the cultivation of Vetiver (Vetiveria zizanoides L. Nash) and the same field was subsequently used for rice (Oryza sativa L.) cultivation. The results showed that V. zizanoides could reduce As concentrations in the field to bring it lower than the maximum permissible limit (20 mg kg-1) in 11 months' time. The rice plants grown in remediated field showed improvement in growth and photosynthesis parameters as compared to that of contaminated field. Importantly, yield related parameters (filled seed, 1000 grain weight, number of panicles etc.) were also significantly higher in remediated field than that in contaminated field. Arsenic concentration in roots, shoot, husk and grains of rice was found to be significantly lower in remediated field than in contaminated field. Grain As decreased from 0.75 to 0.77 μg g-1 dw in contaminated field to 0.15-0.18 μg g-1 dw. In conclusion, replacing rice for single year with V. zizanoides crop can significantly remediate the field and can be a viable option.

Co-cropping vetiver grass and legume for the phytoremediation of an acid mine drainage (AMD) impacted soil

Acid mine drainage (AMD) is a form of environmental pollution from mining activity that can negatively affect soil environments by acidification, salinisation, and metal(loid) contamination. The use of plants to remediate (phytoremediation) these impacted environments while generating plant-based value is a promising approach to more accessible and cost-benefiting restoration of post-mining, marginal lands. In this study, a 3-month growth-chamber pot experiment was conducted to investigate the influence of co-cropping two plant species, Chrysopogon zizanioides (vetiver grass) and the legume Medicago truncatula (barrel clover) with a wheat straw biochar amendment on the phytostabilisation of metal(loid)s Cr, Zn, and As and the phytoextraction of rare earth element (REE) in an AMD impacted soil from a gold mining region in South Africa. The results showed that co-cropping with vetiver significantly lowered the legume's Cr, Zn, and As root contents by 80%, 32% and 54%, respectively, and improved the plant's overall metal(loid) tolerance by increasing its translocation from root to shoot tissue. The biochar further inhibited root uptake of Cr and Zn, by 71% and 36%, and increased the legume biomass by 40%. Both plant species and cropping treatments exhibited low REE extraction capabilities by shoot tissue, which accounted for less than 0.2% of total soil REE contents. The study shows that co-cropping with vetiver and biochar amendment are effective tools for the phytoremediation of AMD impacted soil mainly by lowering plant uptake and improving plant metal(loid) tolerance. Likely mechanisms at play include the alteration of rhizosphere chemistry and species-specific physiological and molecular responses. These effects offer support for the phytostabilisation of AMD impacted soil with the generation of plant-based value through dual (and safe) cultivation (phytoprotection) rather than through REE recovery from plant biomass (phytoextraction). These techniques could allow for the simultaneous restoration of post-mining, mining-impacted and marginal lands with agricultural production.

Root chemistry and microbe interactions contribute to metal(loid) tolerance of an aromatic plant - Vetiver grass

Aromatic plants, such as vetiver grass (Chrysopogon zizanioides), possess strong abilities to resist environmental stresses. However, whether such abilities stem from the interaction between specific chemical characteristics and the associated microbes in roots and rhizosphere remains unclear. We conducted pot experiments to analyze stress-tolerant parameters, organic compounds, and bacterial communities in roots and rhizosphere of vetiver under typical metal(loid) stress [cadmium (Cd), arsenic (As), or Cd + As] over time. The results showed that the vetiver displayed limited toxic symptoms in terms of oxidative stress-antioxidant balance and chlorophyll content. The root low-molecular-weight organic acids (LMWOAs), fatty acids, and sterols were highly sensitive to growth stage (increased from the 4-month to the 8-month stage), and less sensitive to metal(loid) stress. The sugar contents in the rhizosphere soils also notably increased over time. Such endo and rhizosphere chemical changes strongly correlated with and enriched the functional bacteria including Streptomyces, which can resist stress and promote plant growth. The compound-bacteria interaction highly depended on growth stage. Vetiver demonstrated a progressive adaptation to stresses through metabolite modulation and cellular defense reinforcement. Our study evidenced that vetiver shapes the interaction between organic compounds and bacterial community in the root-soil interface and provides notable stress-resistant functions.

Stenocarpella chrysopogonis, a New Species Causing Leaf Streak Disease of Chrysopogon zizanioides in Southern China

Vetiver grass (Chrysopogon zizanioides) has been widely used in recent years for ecological environment management, restoration of degraded ecosystems, and essential oil extraction. In 2019, a leaf streak disease of C. zizanioides was observed in Zhanjiang, Guangdong Province, China. The disease appeared as large streak lesions on the leaves, on which conidiomata were formed. A pathogenicity test with the fungus isolated from these lesions confirmed Koch's postulates and thus the fungus as the causal agent of this disease. A morphological resemblance of the pathogen to Stenocarpella was noted upon microscopic examination. Phylogenetic trees inferred from both individual and combined ITS, LSU, and tef1 sequences confirmed the pathogen as a species of the Diaporthaceae and revealed it to be closely related to Phaeocytostroma and Stenocarpella species. As morphological characters clearly placed the pathogen in the genus Stenocarpella, it was described as S. chrysopogonis.

Enzyme-based green synthesis, characterisation, and toxicity studies of cellulose nanocrystals/fibres produced from the Vetiveria zizanioides roots agro-waste

Vetiver zizanioides roots are considered the most useful part of the plant. It is widely used to extract oil. The aromatic oil is used in perfumery, food-flavouring and cosmetic industries. However, presently, there are no reports available for the usage of vetiver roots agro-waste after oil extraction in nano-based products. Considering the concept of value-added products and green-chemistry approaches, synthesising cellulose nanoparticles (CNPs) using enzymatic treatment from agro-waste has emerged as a viable option. CNP's non-toxicity, biodegradability, and biocompatibility have sparked the industry's interest in its production. Therefore, in the present study, 3 enzymes, cellulase, pectinase, and viscozymes, were used for the green synthesis of CNP. The characterisation of CNP was done using techniques like DLS, FTIR, TEM, SEM, AFM, and TG/DTG, and cytotoxicity of CNP was studied in human skin cell-line (HaCaT) using MTT assay. Results show that CNPs synthesised using viscozyme and pectinase were of crystalline nature (2.0-3.0 nm) and cellulase were of fibres (40-60 nm). The FTIR confirmed that CNPs were devoid of lignin/hemicellulose. The AFM pictures revealed thick and thin nanoparticles with a variety of morphologies. The thermal stability of cellulose was higher compared to CNP. All the synthesised CNPs were crystaline, with a 60-70% crystallinity index. Furthermore, CNP did not show cytotoxic effect on HaCaT cells upto 500 µg/mL concentrations. In conclusion, pectinase and viscosyme may be used for synthesing cellulose-nanocrystals and cellulase enzyme for cellulose-nanofibers from the vetiver roots agro-waste. The findings revealed that Vetiveria zizanioides agro-waste-derived CNP is a sustainable material that can be used as a reinforcing agent/nanocarrier in textile and drug-delivery systems.

Effects of biochar on the physiology and heavy metal enrichment of Vetiveria zizanioides in contaminated soil in mining areas

The effects of biochar addition on the physiological and biochemical characteristics of Vetiveria zizanioides, and the enrichment of heavy metals, were studied herein. The aim was to provide a theoretical reference for biochar to regulate the growth of V. zizanioides in the heavy metal-contaminated soil of mining areas and the enrichment capacity of Cu, Cd, and Pb. The results showed that the addition of biochar significantly increased the contents of various pigments in the middle and late growth stages of V. zizanioides, reduced the contents of malondialdehyde (MDA) and proline (Pro) in each growth period, weakened the peroxidase (POD) activity during the entire growth period; superoxide dismutase (SOD) activity decreased in the initial stages and substantially increased in the middle and late stages. The addition of biochar reduced the enrichment of Cu in the roots and leaves of V. zizanioides, while the enrichment of Cd and Pb increased. In conclusion, it was found that biochar could reduce the toxicity of heavy metals in contaminated soil in the mining area, affect the growth of V. zizanioides and its accumulation of Cd and Pb, and is, therefore, beneficial to the restoration of contaminated soil and the overall ecological restoration of the mining area.

Improving capacity for phytoremediation of Vetiver grass and Indian mustard in heavy metal (Al and Mn) contaminated water through the application of clay minerals

One of the consequences of mining is the release of heavy metals into the environment, especially water bodies. Phytoremediation of areas contaminated by heavy metals using Vetiver grass and Indian mustard is cost-effective and environmentally friendly. This study aimed at enhancing remediation of heavy metal contaminated water through the simultaneous hybrid application of clay minerals (attapulgite and bentonite) and Vetiver grass or Indian mustard. A 21-day greenhouse experiment was carried out to investigate the effectiveness of the clay minerals to improve heavy metal phytoremediation. The highest accumulation of aluminium (Al) by Vetiver grass was 371.8 mg/kg in the BT2.5VT treatment, while for Mn, the highest accumulation of 34.71 mg/kg was observed in the AT1VT treatment. However, Indian mustard showed no significant uptake of heavy metals, but suffered heavy metal toxicity despite the addition of clay minerals. From this study, it was evident that bentonite added at 2.5% (w/v) could improve the phytoremediation capacity of Vetiver grass for Al and Mn polluted water. The current laboratory-scale findings provided a basis for field trials earmarked for remediation in a post-mining coal environment in South Africa. This remediation approach can also be adopted in other places.

Enhanced phytoremediation of atrazine-contaminated soil by vetiver (Chrysopogon zizanioides L.) and associated bacteria

The intensive and long-term use of atrazine (ATZ) has led to the contamination of agricultural soils and non-target organisms, posing a series of threats to human health through the transmission of the food chain. In this study, a 60-day greenhouse pot experiment was carried out to explore the phytoremediation by Chrysopogon zizanioides L. (vetiver). The uptake, accumulation, distribution, and removal of ATZ were investigated, and the degradation mechanisms were elucidated. The results showed that the growth of vetiver was inhibited in the first 10 days of the incubation; subsequently, the plant recovered rapidly with time going. Vetiver grass was capable of taking up ATZ from the soil, with root concentration factor ranging from 2.36 to 15.55, and translocating to the shoots, with shoot concentration factor ranging from 7.51 to 17.52. The dissipation of ATZ in the rhizosphere soil (97.51%) was significantly higher than that in the vetiver-unplanted soil (85.14%) at day 60. Metabolites were identified as hydroxyatrazine (HA), deethylatrazine (DEA), deisopropylatrazine (DIA), and didealkylatrazine (DDA) in the samples of the shoots and roots of vetiver as well as the soils treated with ATZ. HA, DEA, DIA, and DDA were reported first time as metabolites of ATZ in shoots and roots of vetiver grown in soil. The presence of vetiver changed the formation and distribution of the dealkylated products in the rhizosphere soil, which remarkably enhanced the occurrence of DEA, DIA, and DDA. Arthrobacter, Bradyrhizobium, Nocardioides, and Rhodococcus were the major atrazine-degrading bacterial genera, which might be responsible for ATZ degradation in the rhizosphere soil. Our findings suggested that vetiver grass can significantly promote ATZ degradation in the soil, and it could be a strategy for remediation of the atrazine-contaminated agricultural soil.

Biological pilot treatment reduces physicochemical and microbiological parameters of dairy cattle wastewater

The objectives of the present study were to characterize and evaluate a pilot treatment unit (PTU) for dairy cattle wastewater (DCW) in relation to its efficiency in reducing the physicochemical and microbiological parameters and possible application of this fertilizer in organic production. A PTU was set up, composed of the following elements: a dung pit of 7.8 m³, already in place; a septic tank; a set of anaerobic biological filters comprising an upflow filter and a downward-flow filter filled with fragments PVC corrugated conduit; and two constructed wetland systems (CWSs) of horizontal subsurface flow in two parallel routes (Routes 1 and 2), controlled by means of a flow rate divider box. Route 1 passed through CWS 1 cultivated with cattail (Typha domingensis) and Route 2 passed through CWS 2 cultivated with vetiver grass (Chrysopogon zizanioides). To evaluate the treatment stages, biweekly investigations were carried out to collect effluent samples. The results of monitoring, in absolute values, were evaluated by means of the medians and variation coefficients and compared by means of Kruskal-Wallis non-parametric test followed by the Student Newman Keuls test. The treatment efficiencies of Routes 1 and 2 were calculated. The influence of vetiver on the removal of nutrients from the DCW was analyzed and the productivity estimate (t.ha^-1) was performed. CWS 1 was not able to reduce the organic load indices, but it was able to retain fatty material and sodium. CWS 2 showed a reduction in nitrogenous forms and also for other nutrients, achieving the greatest removal of sodium and greatest decay of fecal contamination indicators, thermotolerant coliforms (56.13%), and E. coli (46.82%).

Essential Oils Composition and Biological Activity of Chamaecyparis obtusa, Chrysopogon nigritanus and Lavandula coronopifolia Grown Wild in Sudan

Generally, there are scant data about the constituents and eventually the biological activity of essential oils (EOs) from aromatic plants that grow naturally in Sudan. The present study aimed to determine the chemical composition, and antioxidant and enzyme inhibitory activities of EO extracted from the fruit of Chamaecyparis obtusa (Siebold and Zucc.) Endl. (family Cupressaceae), root of Chrysopogon nigritanus (Benth.) Veldkampis (family Poaceae) and aerial part of Lavandula coronopifolia Poir (family Lamiaceae). The fruit of C. obtusa contained only monoterpenes, mainly hydrogenated ones, with α-pinene (69.07%) as the major component. Oxygenated sesquiterpenes comprised the highest content of the C. nigritanus root EO with cedr-8-en-15-ol (28.69%) as the major constituent while aerial parts of L. coronopifolia contained both monoterpenes and sesquiterpenes and the oxygenated monoterpene lavandulol (26.56%) as dominant compounds. The EO of the root of C. nigritanus significantly displayed (p < 0.05) the highest anti-DPPH radical, Fe³⁺- and Cu²⁺-reducing and metal-chelating activities, while that of C. obtusa fruit significantly exerted (p < 0.05) the best anti-ABTS radical and total antioxidant activity. The two EOs significantly exhibited (p < 0.05) the highest anti-acetylcholinesterase and -butyrylcholinesterase activities, respectively, while EO of L. coronopifolia was the only oil to show a considerable inhibitory effect against the tyrosinase and α-glucosidase enzymes. In conclusion, EOs from these three plants could be natural agents with promising functional properties for food, cosmetics, and pharmaceutical applications.

Optimistic influence of multi-metal tolerant Bacillus species on phytoremediation potential of Chrysopogon zizanioides on metal contaminated soil

The current study investigated the plant growth promoting (PGP) characteristics of multi-metal-tolerant Bacillus cereus and their positive effect on the physiology, biomolecule substance, and phytoremediation ability of Chrysopogon zizanioides in metal-contaminated soil. The test soil sample was detrimentally contaminated by metals including Cd (31 mg kg-1), Zn (7696 mg kg-1), Pb (326 mg kg-1), Mn (2519 mg kg-1) and Cr (302 mg kg-1) that exceeded Indian standards. The multi-metal-tolerant B. cereus seemed to have superb PGP activities including fabrication of hydrogen cyanide, siderophore, Indole Acetic Acid, N2 fixation, as well as P solubilisation. Such multi-metal-tolerant B. cereus attributes can dramatically reduce or decontaminate metals in contaminated soils, and their PGP attributes significantly improve plant growth in contaminated soils. Hence, without (study I) and with (study II) the blending of B. cereus, this strain vastly enhances the growth and phytoremediation potency of C. zizanioides on metal contaminated soil. The results revealed that the physiological data, biomolecule components, and phytoremediation efficiency of C. zizanioides (Cr: 7.74, Cd: 12.15, Zn: 16.72, Pb: 11.47, and Mn: 14.52 mg g-1) seem to have been greatly effective in study II due to the metal solubilizing and PGP characteristics of B. cereus. This is a one-of-a-kind report on the effect of B. cereus's multi-metal tolerance and PGP characteristics on the development and phytoextraction effectiveness of C. zizanioides in metal-polluted soil.

Antimicrobial Formulation of Chrysopogon zizanioides Essential Oil in an Emulsified Lotion for Acne

Acne is a skin condition arising from excess sebum production and microbial overgrowth within the pilosebaceous unit. Several commercial essential oils have shown promising activity against acne-related pathogens. Due to their volatility and thermal instability, the formulation of essential oils into commercial products remains a pharmaceutical challenge. Thus, this study aimed to develop a viable anti-acne topical treatment as an oil-in-water emulsified lotion to overcome these challenges. Chrysopogon zizanioides (vetiver) displayed noteworthy antimicrobial activity with a mean minimum inhibitory concentration of 0.14 mg/mL against Cutibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes. Emulsified lotions containing C. zizanioides were developed through the hydrophilic-lipophilic balance approach. At tested hydrophilic-lipophilic balance values of 8, 9, and 10, C. zizanioides emulsified lotions displayed maximum stability at hydrophilic-lipophilic balance 9 with a minimum change in mean droplet size and polydispersity index of 20.61 and 33.33%, respectively, over 84 days. The C. zizanioides emulsified lotion at optimum hydrophilic-lipophilic balance 9 completely inhibited the growth of C. acnes and killed S. aureus, S. epidermidis, and S. pyogenes within 24 h. Additionally, the lotion retained antimicrobial activity against these test micro-organisms over the 84-day stability test period. Thus, the C. zizanioides emulsified lotion demonstrated physical stability and antimicrobial efficiency, making it an ideal natural product anti-acne treatment.

Exploration of Cytotoxic Potential of Longifolene/Junipene Isolated from Chrysopogon zizanioides

Since ancient times, Chrysopogon zizanioides has been utilized as a traditional medicinal plant for the treatment of numerous ailments, but neither its plant extract form nor its phytoconstituents have been fully explored. With this in mind, the present research was designed to isolate and structurally characterize one of its chemical constituents and evaluate its cytotoxic potential. Therefore, an ethanolic extract of roots was prepared and subjected to column chromatography using solvents of varying polarities. The obtained pure compound was characterized using various chromatographic and spectroscopic techniques such as high-performance liquid chromatography (HPLC), carbon and proton nuclear magnetic resonance (NMR), and liquid chromatography–mass spectroscopy (LC-MS) and identified as longifolene. This compound was evaluated for its cytotoxic potential using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on the prostate (DU-145), oral (SCC-29B) cancer cell line and normal kidney cell line (Vero cells), taking doxorubicin as a standard drug. The obtained outcomes revealed that longifolene possesses cytotoxic potential against both prostate (IC50 = 78.64 µg/mL) as well as oral (IC50 = 88.92 µg/mL) cancer cell lines with the least toxicity in healthy Vero cells (IC50 = 246.3 µg/mL) when compared to doxorubicin. Hence, this primary exploratory study of longifolene exhibited its cytotoxic potency along with wide safety margins in healthy cell lines, giving an idea that the compounds possess some ability to differentiate between cancerous cells and healthy cells.

Effective treatment of acid mine drainage using a combination of MgO-nanoparticles and a series of constructed wetlands planted with Vetiveria zizanioides: A hybrid and stepwise approach

In this novel study, acid mine drainage (AMD) was treated using a hybrid approach comprising a nano-and-biotic system synergistically integrated in a step-wise and modular fashion. Specifically, the treatment chains were made up of different stages, which comprise, neutralization using activated magnesite or MgO-nanoparticles (NPs) (Stage 1) and polishing the product water using a series of wetlands (Stage 2) in a step-wise connection. In stage One (1), real AMD was treated with MgO-NPs at a ratio of 1:100 (1 g/100 mL - w/v ratio), 500 rpm of mixing speed, and One (1) hour of hydraulic retention time (HRT) whilst in stage 2, the final water was fed into constructed wetlands, i.e. Three (3) interconnected wetland with different flow modalities [(I) subsurface vertical flow (SSVF-CW), (II) free water surface flow (FWS-CW), and (III) subsurface horizontal flow (SSHF-CW)], for further purification and polishing to the desired product. In this stage, i.e. stage 2, the product water and substrate were collected daily at the outlet and bottom of each wetland. After the treatment process, the pH of the product water was observed to have increased from 2.6 to 10.4. Significant removal of inorganic contaminants was also observed and the following removal sequence was registered, Fe (99.8%) ≥ Al (99.5%) ≥ Mn (99.24%) ≥ Zn (98.36%) ≥ Cu (97.38%) ≥ Ni (97.7%) ≥ SO₄^2─ (80.59%). Reduction in electrical conductivity (EC) was also observed (86%). Specifically, the nano-part removed the metals and sulphate partially whereas the bio-part effectively removed SO₄^2─ and EC levels, thus denoting stellar combination and complementary performance for the hybrid system in integrated fashion. The state-of-the-art analytical instruments were used to underpin and succinct the fate of chemical species in raw and product MgO-NPs, substrates, and the grass. Finally, the product water conformed to the prescribed standards for effluent discharge hence proving that the synergy of neutralization and bio-remediation, i.e. nano-and-biotic system, could potentially yield the desired results in mine water management and afield. This will go a long way in curtailing ecological footprints associated with mining activities thus fostering the concept of sustainable development.

Reshaping the microenvironment and bacterial community of TNT- and RDX-contaminated soil by combined remediation with vetiver grass (Vetiveria ziznioides) and effective microorganism (EM) flora

Explosive pollutants remaining in global soils are serious threats to human health and ecological safety. Soils contaminated by trinitrotoluene (TNT) and cyclotrimethylene trinitramine (RDX) are simulated in this study and remediated using vetiver grass and effective microorganism (EM) flora to determine the efficacy of combined remediation in reshaping the microenvironment and bacterial community of soils contaminated by explosives. The degradation rates of TNT and RDX after 60 days of combined remediation were 95.66% and 84.37%, respectively. Soil microbial activity and enzyme activities related to the nitrogen cycle were upregulated. The content of soil elements in the remediation group changed significantly. Vetiver remediation increased the diversity and significantly changed the structure of the microbial community. Notably, bacteria, such as Sphingomonadaceae and Actinobacteriota, which can degrade explosives, occupied the soil niche, and the Proteobacteria and Bacteroidota, which are involved in sugar metabolism, showed particularly increased abundance. The metabolism of soil carbohydrates, fatty acids, and amino acids was upregulated in the vetiver, EM flora, and combined vetiver+EM flora remediation groups, and the most significantly upregulated pathway was galactose metabolism. The combined vetiver and EM flora treatment of soil contaminated by explosives greatly improved the ecology of the soil microenvironment.

Enhanced adsorption of metal ions onto Vetiveria zizanioides biochar via batch and fixed bed studies

The study highlights the potential of Vetiveria Zizanioides derived biochar for heavy metal removal in multicomponent systems. Biochar efficiency varies with pH, metal ion concentration and residence time. Maximum removal efficiency was found to be 66.34, 67.23, 46.54, 69.92, 68.23 and 63.34% for Arsenic, Copper, Nickel, Cadmium, Lead and Chromium at 90 min respectively. Ternary system revealed that Copper ions have inhibitory effect on Lead ions and have lower adsorption capacity than binary system. Multicomponent isotherm model was used to analyse simultaneous adsorption of metal ions and shows a good fit with modified Langmuir model for binary and ternary systems. Fixed-bed column was tested for scale-up feasibility and maximum adsorption capacity of 139, 130, and 123 mg/g for Lead, Copper, and Nickel ions were obtained at 1.5 L/h and a bed height of 12 cm. In fixed bed column, multicomponent sequence provides more protection against premature exhaustion of biochar.

Toxicity-removal efficiency of Brassica juncea, Chrysopogon zizanioides and Pistia stratiotes to decontaminate biomedical ash under non-chelating and chelating conditions: A pilot- scale phytoextraction study

The healthcare community acknowledged that bio-medical wastes (BMWs) have reached a colossal level across the globe. The recent pandemic (COVID-19) has brought a deluge of contaminated waste which calls for an urgent need of treatment technology for its safe disposal. BMW generally undergoes a conservative treatment approach of incineration which in turn generates potentially toxic ash known as BMW ash. BMW ash, if directly dumped in landfill, leaches and further pollutes both land and groundwater. The present study deployed Brassica juncea [Indian Mustard (IM)], Chrysopogon zizanioides [Vetiver Grass (VG)], and Pistia stratiotes [Water Lettuce (WL)] to remediate toxicity of potentially toxic elements (PTEs) i.e., Cd, Al, Pb, Cu, Mn, Co and Zn in BMW ash both in the presence and absence of chelate with an increased dosage of toxicity. The phyto-assessment results showed that IM extracted 202.2 ± 0.1-365.5 ± 0.02, 7.8 ± 0.03-12.5 ± 0.3, 132.1 ± 0.1-327.3 ± 0.1 and >100 mg kg^-1 of Al, Cd, Pb and Zn, respectively without the assistance of a chelating agent. The VG accumulated heavy metals in greater concentration up to 10.5 ± 0.1 and 290.1 ± 0.05 mg kg^-1 of Cd and Zn, respectively, and similar trends were observed in the WL set-up. However, the application of an ethylene diamine tetraacetic acid (EDTA) had also increased the efficiency on an average by 20-30% for IM, 35-45% for VG, and 25-35% for WL. The experimental set-up shows that the BCF for IM, VG and WL was found to be greater than 1 for most of the PTEs. The higher value of BCF resulted in a better ability to phytoextract the heavy metals from the soil. The results suggested that IM, VG and WL have the potential to phytoextract PTEs both in the absence and presence of chelating agents.

Novel agrotechnological intervention for soil amendment through areca nut husk biochar in conjunction with vetiver grass

Soil quality management through effective utilization of agricultural residue is the cynosure of intense global research. Therefore, we have explored the pyrolytic conversion of a locally available agricultural residue, the areca nut husk (AH), into biochar (BC) as a sustainable option towards residue management. The AH was carbonized at 250-400 °C, and residence times of 30-90 min. Subsequent detailed analysis revealed areca nut husk biochar (AHBC) formed at 250 °C with 60 min residence time, had the highest soil organic matter yield index (SOMYI), the lowest H/C and O/C ratio, and an average particle size of 1191.6 nm. Further characterization exposed the highly porous structure of prepared AHBC with oxygenated functional groups attached to its surface. The application of AHBC in conjunction with vetiver (Chrysopogon zizanioides L.) was used as a novel agrotechnological approach to assess soil quality improvement. Various doses of AHBC (5 t ha^-1, 10 t ha^-1, and 15 t ha^-1) were applied in the experimental soils, and the principal component analysis (PCA) revealed that the 15 t ha^-1 dose was optimum for the growth of the vetiver. AHBC amendment in soil resulted in increase of plant height and relative water content. This could be attributed to the increase in organic carbon, cation exchange capacity, and nutrients in the soil. Application of AHBC along with vetiver could be a simple, yet effective option, for sustainable agricultural residue and soil management.

Vertical phytoremediation of wastewater using Vetiveria zizanioides L

In many areas, wastewater feeds water bodies, which leads to it being non-usable for agricultural and other uses. Phytoremediation is a scientific approach which cleans contaminated waters, demanding large areas for application. Vertical agriculture is a new method to compact plant cultures. This study investigates vertical wastewater phytoremediation (VWP). Twenty vetiver grasses were planted in a hydroponic vertical agriculture system. Wastewater flowed into the system in four different flow rates, 60, 80, 100, and 160 l day^-1 and water purity was assessed in order to measure the remediation ability of the VWP. Results showed a reduction in biochemical oxygen demand (BOD5 and NO₃^- concentrations and an increase of electrical conductivity (EC) and dissolved oxygen (DO) in the outlet. Maximum and minimum (BOD5) reduction percentage (78.47% and 67.36%) and NO₃^- removal percentage (90.53% and 36.41%) occurred in flow rates 60 and 160 l day^-1, respectively. With the increase of wastewater flow rate, phytoremediation performance decreased, but the performance of VWP with vetiver grass was efficient enough to enable wastewater remediation. Scaling up VWP with Vetiver and related competitive plant species holds promise for wastewater remediation for both human and ecosystem services.

Effects of Herbaspirillum sp. p5-19 assisted with alien soil improvement on the phytoremediation of copper tailings by Vetiveria zizanioides L

Microbial assisted phytoremediation and reclamation are both potential contaminated soil remediation technologies, but little is known about the combined application of the two technologies on real contaminated soils. This study investigated the potential of Herbaspirillum sp. p5-19 (p5-19) assisted with alien soil improvement on improving stress tolerance and enhancing the accumulation of Mn, Cu, Zn, and Cd by Vetiveria zizanioides L. in copper tailings. Phytoremediation potential was evaluated by plant biomass and the ability of plants to absorb and transfer heavy metals. Results showed that the biomass was increased by 19.64-173.81% in p5-19 inoculation treatments with and without alien soil improvement compared with control. Meanwhile, photosynthetic pigment contents were enhanced in co-inoculation treatment (p5-19 with alien soil improvement). In addition, the malondialdehyde (MDA) content was decreased, and the activities of antioxidant enzymes such as ascorbate peroxidase (APX), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were increased in p5-19 treatment, thereby alleviating the oxidative stress. Moreover, co-inoculation significantly (p < 0.05) increased the concentrations of Mn, Cu, Zn, and Cd in the roots and shoots of V. zizanioides. In particular, the highest concentrations of Mn, Zn, and Cd in the shoots (roots) were obtained in covering 10 cm combined with p5-19 inoculation treatment, which were 4.44- (2.71-), 4.73- (3.87-), and 5.93- (4.35-) fold as that of the controls, respectively. These results provided basis for the change of phytoremediation ability of V. zizanioides after inoculation. We concluded that p5-19 assisted with alien soil improvement was a potential strategy for enhancing phytoremediation ability in tailings.

Analysis of potential of Napier grass, Vetiver and Equisetum plants for the treatment of domestic greywater using box-type constructed wetlands

The management of wastewater generated as a byproduct of various human activities from agricultural, industrial, and domestic sectors is a matter of global concern today. Greywater is a class of wastewater generated from the domestic sector. Greywater management can be done effectively by treating greywater at the source itself. In this context, constructed wetlands (CWs) come handy with low-tech, environmental, and economic-friendly options. In the present study, box-type horizontal subsurface flow constructed wetlands were designed and the efficiency of Napier grass (Pennisetum purpureum), Vetiver (Vetiveria zizanioides), and Equisetum (Equisetum hyemale) were assessed in treating domestic greywater. There was a drastic significant increase in DO with 47.0% in Vetiver, 92.5% in Napier grass, and 97.2% in Equisetum. The average percent pollutant removal of some major parameters was 92.4% for turbidity, 92.7% for acidity, 81.3% for BOD, 91.0% for COD with Napier grass. In the case of Vetiver, the removal percent was 82.5% turbidity, 87.9% acidity, 81.8% BOD, and 92.9% COD. For Equisetum, the average pollutant removal efficiency varied with 94.6% turbidity, 91.4% acidity, 80.0% BOD, and 88.1%COD. The study thus proves the efficiency of all the three plants to be used in box-type constructed wetlands.

Differential protein abundance of vetiver grass in response to acid mine drainage

Acid mine drainage (AMD) is an acidic and metalliferous discharge that imposes oxidative stress on living things through bioaccumulation and physical exposure. The abandoned Tab-Simco mining site of Southern Illinois generates highly acidic AMD with elevated sulfate (SO₄ ^2- ) and various metals. Vetiver grass (Chrysopogon zizanioides) is effective for the remediation of Tab-Simco AMD at both mesocosm and microcosm levels over extended periods. In this study, we conducted a proteomic investigation of vetiver shoots under short and long-term exposure to AMD. Our objective was to decipher the physiological responses of vetiver to the combined abiotic stresses of AMD (metal and low pH). Differential regulation was observed for longer-term (56 days) exposure to AMD, which resulted in 17 upregulated and nine downregulated proteins, whereas shorter-term (7 days) exposure led to 14 upregulated and 14 downregulated proteins. There were significant changes to photosynthesis, including upregulation of electron transport chain proteins for light-dependent reactions after 56 days, whereas differential regulation of enzymes relating to C₄ carbon fixation was observed after 7 days. Significant changes in amino acid and nitrogen metabolism, including upregulation of ethylene and flavonoid biosynthesis, along with plant response to nitrogen starvation, were observed. Short-term changes also included upregulation of glutathione reductase and methionine sulfoxide reductase, whereas longer-term changes included changes in protein misfolding and ER-associated protein degradation for stress management and acclimation.

Chrysopogon zizanioides-a review on its pharmacognosy, chemical composition and pharmacological activities

Vetiver is a traditional plant with versatile applications in medicine, aroma, commerce, environmental-protection, and agriculture. This review was designed to compile all the latest information on phytochemistry, pharmacology, and traditional uses of C. zizanioides. All the information related to this plant was gathered from several authentic sites, using keywords like Chrysopogon zizanioides, Vetiveria zizanioides, Khus, and Khas-Khas. The included resources were journaled articles, book chapters, books, Ayurvedic Pharmacopoeias, and Ayurvedic Formulary of India, from science direct, PubMed, research gate etc. All the necessary, relevant, authentic, and updated information were tried to inculcate in the manuscript. The literature was collected via online sites like Pub med, Scopus, and Science direct as well. During compilation, it observed that many traditional utilities of vetiver got their authentication when tested using different disease-based pharmacological models taking various extracts of roots, leaves, and root oil as test samples. However, systematic studies for isolation of active constituents and establishing their mechanism of action are still required to be validated. On the other hand, the development of novel and robust techniques needed for oil extraction can further enhance the exploration of biological utilities faster. Moreover, the cultivators and harvesters must address carefully to prevent the linked drawback of soil erosion.

Evaluating the bio-removal of crude oil by vetiver grass (Vetiveria zizanioides L.) in interaction with bacterial consortium exposed to contaminated artificial soils

Remediation of crude oil-impacted areas is a major pervasive concern in various environmental conditions. The major aim of this study was to investigate the collaboration of vetiver grass (Vetiveria zizanioides L.) and petroleum hydrocarbon-degrading bacteria to clean up contaminated soils. Vetiver grass and five native bacterial isolates were used in one consortium to remediate contaminated soil by crude oil at various concentrations (2.0, 4.0, 6.0 8.0, 10, and 12.0% w_oil/w_soil). The presence of isolated bacteria caused a significant (p < 0.05) increment of root-shoot ratio of vetiver in contaminated soils in comparison to non-contaminated soil. The combination of vetiver and bacterial consortium revealed efficient dissipation of more than 30% of low-molecular-weight polycyclic aromatic hydrocarbons (PAHs) and more than 50% of high-molecular-weight PAHs in all crude oil concentrations. The removal of n-alkanes in the simultaneous presence of the bacteria and plant was more than 70.0% at 10.0% of oil concentration, whereas the removals in control were 20.7, 13.7 and 9.2%, respectively. The hydrocarbons dissipation efficiency of applied treatments decreased at 12.0% of contamination. It is concluded that a combination of vetiver grass and the isolated bacteria could be a feasible strategy for remediation of crude oil-polluted soils. Novelty statementDetermination of the responses of vetiver grass under different crude oil concentrations is one of the novelties of the present study, which is helpful for demonstrating plant tolerance on polluted environments. Also, it adds information about the potential of this grass to clean up crude oil-polluted soils solely as well as in the presence of promising selected bacterial strains.

The adsorption properties of functionalization vetiver grass-based activated carbon: the simultaneous adsorption of phosphate and nitrate

In this work, zirconium chloride octahydrate/CTAB/vetiver grass-activated carbon (ZR/CTAB/VGAC) was prepared from vetiver grass-activated carbon (VGAC), using zirconium chloride octahydrate (ZR) and cetyltrimethylammonium bromide (CTAB) as modifiers. The optimized conditions of the simultaneous phosphate and nitrate removal by ZR/CTAB/VGAC were discussed, including amount of adsorbent, initial concentration, pH, contact time, and temperature. The simultaneous removal efficiency of phosphate and nitrate was 96.50% and 51.17% under optimized conditions. The structural and morphology of ZR/CTAB/VGAC was investigated by using automatic volumetric adsorption analyzer (BET), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), and Fourier transform infrared spectroscopy (FTIR). It was found that the removal efficiencies of phosphate and nitrate were enhanced dramatically because ZR and CTAB were introduced on the surface of VGAC after modification. Moreover, the adsorption data fitted significantly well with Freundlich isotherm model. It was described well by pseudo-second-order kinetic model. Phosphate and nitrate adsorbed via chemisorption (ion exchange) by ZR, CTAB, and functional groups of the surface of ZR/CTAB/VGAC. Electrostatic adsorption of AC in ZR/CTAB/VGAC also played an important role in the adsorption process. ZR/CTAB/VGAC is an excellent adsorbent, which could be applied to remove nitrate and phosphate from wastewater.

Simultaneous removal of arsenic, fluoride, and manganese from synthetic wastewater by Vetiveria zizanioides

Main aim of the present research is to explore the potential use of Vetiveria zizanioides L. for phytoremediation of arsenic, fluoride, and manganese simultaneously from synthetic wastewater in a batch scale floating platform unit. Half strength Hoagland's nutrient solution spiked with arsenic, fluoride, and manganese concentrations of 1, 20, and 10 mg/L, respectively has been used. The effects of pH and treatment time on simultaneous removal of arsenic, fluoride, and manganese have been performed. V. zizanioides has exhibited optimum growth at pH 8 and the removal of arsenic and fluoride is observed to be 59.6 and 38.1%, respectively. This plant has successfully removed all of the manganese (99.3%). The uptake of manganese is found to be faster than the arsenic and fluoride. The trend of arsenic, fluoride, and manganese accumulation in various parts of V. zizanioides is found as roots > stems > leaves. Result showed that the use of V. zizanioides would be appropriate to treat arsenic, fluoride, and manganese contaminated wastewater.

Potential therapeutic effect of Chrysopogon zizanioides (Vetiver) as an anti-inflammatory agent

Vetiver has a broad history of traditional medicinal uses, but only a handful of research article has reported its utility in treating diseases. But unfortunately, no work has been reported on the anti-inflammatory activity of its plant extract and inflammatory-linked diseases. Hence, the present review focuses on investigating the several presumptions which can be put forward to explain its anti-inflammatory property. Thus, for ensuring the same, all the databases like science direct, PubMed, book chapters, and other authenticated papers were thoroughly studied to present a connection between inflammation and the plant potential. After gaining enough knowledge on pathogenesis of inflammation, it has been observed that the release of mediators from the arachidonic acid metabolism pathway and generation of oxidative and nitrogen species are presented as the main reason for the occurrence of inflammation condition. The stimulation of antioxidant enzyme system network by the plant extract reduces the level of oxidative stress, creating a balance between oxidant and antioxidant system. Moreover, its antimicrobial activity will prevent the biological source of stimulation towards injury and the CNS depressant effect will subside the pain of inflammation. Amalgamating all the factors together, the plant can be utilized as anti-inflammatory can be and also can be proved as a beneficial perspective in the treatment of inflammation-linked disorders.

Application potential of Chrysopogon zizanioides (L.) Roberty for the remediation of red mud-treated soil: an analysis via determining alterations in essential oil content and composition

The present study is of significant importance because phytoremediation of metals in red mud using essential oil-bearing plants such as Chrysopogon zizanioides (commonly known as vetiver) is a potential alternative for on-site management of the waste in most economical and sustainable way. Vetiver is a potential metal tolerant plant with high economic value; therefore the present study was accomplished to evaluate the impacts of metals in red mud on essential oil content and composition, used for remediation and stabilization of dumps. Novelty of the study is that, it aimed to utilize red mud along with sewage-sludge to cultivate vetiver which offers twin benefits, i.e. phytoremediation of metals in red mud coupled with improved quantity and quality of high valued essential oil without metal contamination.

Beneficiary of nitrifying bacteria for enhancing lettuce (Lactuca sativa) and vetiver grass (Chrysopogon zizanioides L.) growths align with carp (Cyprinus carpio) cultivation in an aquaponic system

The aquaponic system is an alternative strategy to treat aquaculture waste and achieve food independence. Bacteria play vital roles in the aquaponic system as they can transform ammonia or ammonium into nitrite and then into nitrate, which is more favorable for bacteria, fish, and plants. The objective of this study was to determine the effect of nitrifying bacteria (Nitrosomonas europaea Winogradsky and Nitrobacter winogradskyi Winslow) on the aquaponic system in terms of water quality, nutrient availability, and productivity of carp (Cyprinus carpio), lettuce (Lactuca sativa var. crispa), and vetiver grass (Chrysopogon zizanioides L.). The experiment consisted of four treatments: aquaculture of carp as a control for fish (A), hydroponic of lettuce and vetiver grass without nutrient addition as a control for plants (B), aquaponic (carp, lettuce, vetiver grass) (C), and aquaponic with nitrifying bacteria addition (D). The results showed nitrifying bacteria addition had a significant effect on daily growth rate (DGR) and relative growth rate (RGR) of lettuce within a treatment; on the other hand, the nitrifying bacteria did not give a significant effect to RGR of vetiver grass. The growth rate, specific growth rate, and survival rate of the carp in aquaculture treatment (A) were lower than in both aquaponic treatments (C and D). Nitrifying bacteria addition in the aquaponics system had a significant effect of increasing the orthophosphate concentration. Water quality was also indicated to be better in the aquaponic system than in the aquaculture system. The integration of aquaculture and hydroponics with the addition of nitrifying bacteria enables the formation of microorganism communities, nitrate, and orthophosphate, which lead to the improvement of water quality, nutrient availability, and plant growth.

Accelerated remediation of organochlorine pesticide-contaminated soils with phyto-Fenton approach: a field study

Phytoremediation and advanced oxidation processes are among the most promising techniques for removing organic pollutants from soils. A field trial was performed for six months to evaluate the effect of nano-Fe₃O₄ on the degradation of organochlorine pesticide residues including Lindane, p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), and p,p'-dichlorodiphenyldichloroethane (DDD) in pesticide-contaminated soils in the presence of vetiver in Bac Giang province, Vietnam. Vetiver was planted in three zones with different nano-Fe₃O₄ concentrations. Soil samples from each zone were periodically collected to determine the remaining concentrations of selected organochlorine pesticides via gas chromatography-electron capture detector. Results indicated that the total DDT concentrations in the examined soil were 1.9-13 times higher than the permissible threshold level (10 µg g^-1) established by the national technical regulation on pesticide residues in soil. The (p,p'-DDE + p,p'-DDD)/p,p'-DDT ratios ranged from 13.5 to 114, indicating the absence of recent inputs of technical DDTs at the study area. DDT dechlorination mainly occurred under aerobic pathways to form DDE. Furthermore, DDE degradation in soil was adequately described by the pseudo-first-order kinetics model (R² > 0.892). In the presence of vetiver, the rate constants of DDE degradation were 0.264, 0.350, and 0.434 month^-1 with 0, 25, and 100 mg kg^-1 of added nano-Fe₃O₄, respectively, indicating that the degradation of DDE correlated positively with Fe₃O₄ concentration in the soil. Additionally, the presence of vetiver and nano-Fe₃O₄ in the soil increased DDT removal rates, which might be linked to the involvement of Fenton/Fenton-like reactions.

Removal of tetracycline and ciprofloxacin from wastewater by vetiver grass (Chrysopogon zizanioides (L.) Roberty) as a function of nutrient concentrations

Antibiotics have been widely used not only for the treatment and prevention of human infectious diseases but also to promote growth and prevent infections in farm animals. These antibiotics enter the environment via wastewater treatment plants, most of which cannot remove them. In addition to antibiotics, nutrients such as nitrogen (N) and phosphorus (P) also create major environmental pollution problems in surface water. Previously, we reported that vetiver grass [Chrysopogon zizanioides (L.) Roberty] successfully removed antibiotics from secondary wastewater effluent. In this study, our objective was to evaluate the potential of vetiver grass to remove two antibiotics, ciprofloxacin (CIP) and tetracycline (TTC), from wastewater in the presence of high N and P. Our results show that vetiver grass significantly (p < 0.05) removed antibiotics (60-94% CIP and 89-100% TTC) and nutrients (78-89% N and 71-97% P) from the secondary wastewater effluent. The removal of antibiotics dropped with increasing nutrient concentrations. The removal efficiency was mainly affected by the presence of N rather than P in the secondary wastewater effluent. The presence of CIP induced more stress on vetiver grass compared to TTC. Vetiver also removed total organic carbon (48-73%) and chemical oxygen demand (73-82%), but their removal was also affected by the nutrient content in the secondary wastewater effluent.

Phytoremediation of petroleum hydrocarbon-contaminated soils with two plant species: Jatropha curcas and Vetiveria zizanioides at Ghana Manganese Company Ltd

The study investigated the effects of Jatropha curcas (JC) and Vetiveria zizanioides (VZ) on hydrocarbon concentration levels in mine spoils. A 2 × 2 × 3 factorial arrangement of treatments in a completely randomized design with 3 replications was adopted. With compost amendments, JC caused 78.8 and 82.2% and VZ caused 51.1 and 39.7% decline in soil TPH and TOG concentrations, respectively after 16 weeks. Compost amendments significantly reduced TOG and TPH concentrations compared to the other treatments in both JC and VZ (p < 0.0001). However, the effect of species on TOG and TPH concentrations were marginally significant (p = 0.081 and p < 0.006, respectively). Growth in height, collar diameter and number of leaves in JC were significantly higher in the compost amendment compared to the fertilizer and control treatments (p < 0.0001). Number of leaves (p = 0.009) and collar diameter growth (p = 0.010) were significantly lower in contaminated soils compared to non-contaminated soils. Furthermore, only the number of tillers in Vetiver was significantly influenced by the soil amendments (p = 0.003) and the soil hydrocarbon levels (p = 0.048). It is concluded that phytoremediation particularly with JC is an alternate means to reducing soil hydrocarbon concentration levels. However, soils must be amended with compost for effective remediation and rapid, vigorous, early growth of plants.

Facilitated decrease of anions and cations in influent and effluent of sewage treatment plant by vetiver grass (Chrysopogon zizanioides): the uptake of nitrate, nitrite, ammonium, and phosphate

The ability of vetiver grass (Chrysopogon zizanioides L.) for the reduction of anions and cations especially inorganic nitrogen compounds from the influent and effluent of sewages was investigated. Vetiver grass was grown hydroponically in influent (IN) and four different effluent (EF) sewages including control, 125 (EF125), 250 (EF250), and 500 (EF500) mg L^-1 Ca(NO₃)₂. During 18 days, phosphate concentration gradually declined in both influent and all effluent treatments. Unlike effluent treatments, the amount of ammonium in influent was greater than the standard (39.52 mg L^-1) and decreased severely down to 4.85 mg L^-1 at the end of the experiment. After just 48 h, the concentration of nitrate in EF treatment reached 2.25 mg L^-1 that is lower than the standard. The decrease of nitrate to concentrations less than the standard was also observed at days 8, 11, and 18 in EF125, EF250, and EF500 treatments, respectively, and about 90% of nitrate had been removed from 500 mg L^-1 Ca(NO₃)₂ treatment. Other ions such as Cl^-, Ca²⁺, and K⁺ decreased in influent and all effluent sewages due to phytoremediation process. Accordingly, phytoremediation by vetiver grass could decrease concentrations of nitrate, ammonium, phosphate, chloride, and calcium in influent and all effluent sewages. Increasing the concentration of nitrate resulted in the increase in its uptake rate. In addition, a positive correlation was shown between the uptake rate of nitrate by vetiver grass and the duration of cultivation of this plant in nitrate-containing medium.

High efficiency phytoextraction of uranium using Vetiveria zizanioides L. Nash

Uranium uptake, translocation and its effects on leaf anatomy in vetiver grass (Vetiveria zizanioides L. Nash) grown in hydroponics were investigated at a wide range of concentrations. At concentrations below 200 ppm (1, 5, 25, 100, and 200 ppm) almost 90-95% of uranium was depleted from the medium within 3 days of treatment, while at other concentrations viz., at 318, 500, 619, 1,000, 5,000, 7,500, and 11,900 ppm, it reached a maximum between 7 and 14 days, with a marginal increase in the depletion thereafter. Most of the uranium could be recovered from plants at concentrations below 200 ppm. On the contrary, a significant reduction in the recovery of uranium was noticed at higher concentrations and the percentage of recovery dropped from 82% at 318 ppm to 35% at 11,900 ppm. While most of the uranium taken up by the plants could be recovered from roots at lower concentrations, a preferential translocation of the element to shoot occurred at concentrations beyond 1,000 ppm. Histological studies of leaves from plants treated with 1,000 ppm uranium displayed the formation of multilayered cells between the epidermis and vascular bundles on the adaxial side in the distal regions of the leaves. The plants were also found to tolerate and survive the radiological and chemical constituents of both uranium mill tailings soil as well as various effluents of uranium mine and mill operations. Further, they could also survive in uranium ore containing 600 ppm of triuranium octoxide (U₃O₈) and could withstand the amendment of ore with citric acid. The ability of vetiver to take up uranium from solutions to high levels and its survival in effluents, mill tailings soil, and ore coupled with its ecological characteristics makes it an ideal plant for phytoextraction of uranium.

Removal of antibiotics and nutrients by Vetiver grass (Chrysopogon zizanioides) from secondary wastewater effluent

Persistence of antibiotics in soil and aquatic ecosystem is the primary reason for the emergence of antimicrobial resistant microorganisms. After consumption, antibiotics are poorly retained in our body, and a major fraction is excreted out. These bioactive compounds end up in wastewater. The routine treatment practiced by the conventional wastewater treatment plants does not remove the entire load of antibiotics. Cost-effective and environment-friendly treatment technologies need to be developed to address this issue. Vetiver system is being adapted throughout the world due to its removal capacity and high tolerance toward several toxic organic and inorganic pollutants. In this study, we investigated the potential of vetiver (Chrysopogon zizanioides), a fast-growing, perennial grass capable of growing in a hydroponic setup, to remove two widely prescribed antibiotics, ciprofloxacin (CIP) and tetracycline (TTC) from secondary wastewater effluent. Significant (p < 0.05) removal of antibiotics and nutrients (N & P) by vetiver grass from secondary wastewater effluent was observed within 30 days. Vetiver grass removed more than 90% antibiotics from secondary wastewater matrix. In addition to antibiotics, vetiver grass also removed nitrate (>40%), phosphate (>60%), total organic carbon (>50%), and chemical oxygen demand (>40%) from secondary wastewater effluent.

The performance of vetivers (Chrysopogon zizaniodes and Chrysopogon nemoralis) on heavy metals phytoremediation: laboratory investigation

Phytoremediation with vetiver was investigated in relation to heavy metal contaminated soil in Thailand. The work compared the performance of two species of vetiver named Songkhla 3 (Chrysopogon zizaniodes) and Prachuap Khiri Khan (Chrysopogon nemoralis) in absorbing lead, zinc, and cadmium in contaminated soils. Toxicity Characteristic Leaching Procedure (TCLP), and Allium tests were conducted to determine toxicity of treated soil. Ethylenediaminetetraacetic acid (EDTA) was also used to increase heavy metals concentration in solution in soil, which led to an increase in translocation and bioaccumulation factors. In general, results showed that concentration of heavy metals decreased in soil and increased in both the shoots and roots of vetivers during a 4-month treatment period. TCLP results indicated that the concentration of zinc and cadmium in contaminated soil was reduced over treatment time, and significantly increased after EDTA was applied. To confirm vetiver performance in phytoremediation, Allium testing showed that remained heavy metals in treated soils had no effect on nucleus aberration. Songkhla 3 and Prachuap Khiri Khan showed similar trends in their ability to remediate lead, zinc, and cadmium from contaminated soil. Both species could accumulate higher concentrations of heavy metals in their shoots and roots over time, and with EDTA application.

Phytoremediation potential of vetiver grass irrigated with wastewater for treatment of metal contaminated soil

A field experiment was conducted to understand the potential of vetiver grass (Vetiveria zizanioides) in heavy metal uptake from the soil and wastewater. Four main irrigation treatments including T₁ (treated industrial wastewater), T₂ (1:1 ratio of municipal:industrial wastewater), T₃ (treated municipal wastewater) and T₄ (fresh water) were applied. Moreover, the effect of arbuscular mycorrhizal fungus (AMF), Glomus mosseae, on plant growth and heavy metal concentration was evaluated. Three main criteria including bioconcentration factor (BCF), translocation factor (TF) and heavy metal uptake were applied to assess the potential of vetiver grass in accumulation and translocation of heavy metals to aerial parts. The highest concentration of heavy metals was found in plant and soil irrigated with T₁ treatment followed by T₂, T₃ and the lowest concentrations were found in T₄ treatment. Irrigation with treated municipal wastewater led to a significant increase in plant biomass and heavy metal uptake compared to other treatments. In T₁ treatment (industrial wastewater), vetiver grass caused a significant decrease in Zn, Fe, Cu, Cd and Pb concentrations in soil as compared to no-plant treatment (without planting vetiver grass). Therefore, vetiver grass, irrigated with treated industrial wastewater, is a promising method for the development of urban and industrial green space.

Enhanced uptake of Cd by biofilm forming Cd resistant plant growth promoting bacteria bioaugmented to the rhizosphere of Vetiveria zizanioides

Heavy metals are the major cause of pollution and cadmium is one among the highly toxic metals discharged into the environment from various industries. The current study was focused on the bioremoval of cadmium by phyto and rhizoremediation approach using Vetiveria zizanioides. The bacterial strains were isolated from wetland paddy rhizosphere soil and the isolate VITJAN13 was found to be a biofilm forming Cd resistant plant growth promoting rhizobacteria (PGPR). The 16S rRNA gene sequencing revealed VITJAN13 to be the closest neighbor of Aeromonas sp. and was submitted to Genbank with the accession number KX770741. Further, pot culture studies indicated that the treatments bioaugmented with VITJAN13 increased the root length and shoot height by 21.4 and 17.36%, respectively as compared to the non-augmented plants. Hence, bioaugmentation of Aeromonas sp. in the rhizosphere of Vetiveria zizanioides enhanced the uptake of cadmium by 67.7% in the soil treated with 15 mg/kg of Cd to that of the phytoremediation setup.

A Cold Process Preparation of Vetiveria zizanioides (L.) Nash Oil Lotions using Simulgel FL as an Emulsifier

Vetiveria zizanioides (vetiver) contains viscous volatile oil, which has the ability to repel mosquitoes similar to citronella oil, a well-known mosquito repellent in tropical countries, like Thailand. The objectives of the current study were to formulate the stable oil-in-water vetiver oil lotions using Simulgel FL as a liquid emulsifier, to investigate the physicochemical properties of the prepared lotions and to evaluate the in vitro release characteristics of the stable vetiver oil lotions. In this work, the concentrations of Simulgel FL ranged from 1% to 3% weight in weight, whereas the concentrations of vetiver oil were varied: 2.5%, 5%, and 10% weight in weight. The suitable concentration of Simulgel FL was found to be 3% weight in weight. For comparison purposes, oil-in-water citronella oil lotions (10% weightin- weight citronella oil) were also prepared with similar ingredients. A mixture of vetiver oil and citronella oil (1:1 by weight) was also used as an active ingredient. By using Simulgel FL, the lotions could be prepared using a cold process (without heat). The physicochemical properties (appearance, pH, viscosity) of the stable lotions were satisfactory. All prepared lotions possessed weak acidic pH values with pseudoplastic flows. Using modified Franz diffusion cell and synthetic membrane, the release rates of vetiver oil were relatively lower than those of citronella oil.

Comparison of boron uptake and translocation in two vetiver genotypes and evaluation of boron removal efficiency of vetiver floating islands

The objectives of this study were to identify genotypic differences in the uptake and translocation of boron (B) in vetiver (Chrysopogon zizanioides L.), a promising species in B phytoremediation, and to determine the efficiency of vetiver floating island system in B phytoremediation. Changes in plant biomass and B uptake and translocation were determined in two vetiver genotypes, Sierra and Sunshine, cultured hydroponically in a nutrient solution and exposed to six different B concentrations for 7 d and 14 d. The efficiency of B removal by Sierra (a high B accumulative genotype) grown in floating islands was also determined. Shoot B concentration differed significantly between the two genotypes but differences in root concentration were not significant. Root to shoot B transfer and B uptake ability were higher in Sierra than in Sunshine. The uptake and translocation of B was affected by B concentration and time of exposure. Sierra plants grown in floating islands were more efficient in B removal at lower B concentrations. Most of the B removed accumulated in the middle-upper sections of old leaves. Sierra is more suitable for the removal of B from wastewaters than Sunshine, especially in vetiver floating island system.

Enhancement of toxic Cr (VI), Fe, and other heavy metals phytoremediation by the synergistic combination of native Bacillus cereus strain and Vetiveria zizanioides L

Bioremediation of Cr (VI), Fe, and other heavy metals (HMs) through plant-microbes interaction is one of the efficient strategies due to its high efficiency, low cost, and ecofriendly nature. The aim of the study was to isolate, characterize, and assess the potential of rhizospheric bacteria to enhance growth and metal accumulation by the chromium hyperaccumulator Vetiveria zizanoides. The bacterial strain isolated from mine tailings was identified to be Bacillus cereus (T1B3) strain exhibited plant growth-promoting traits including, 1-aminocyclopropane-1-carboxylate deaminase, indole acetic acid, and siderophores production, nitrogen fixation, and P solubilization. Removal capacity (mg L^-1) of T1B3 strain was 82% for Cr⁺⁶ (100), 92% for Fe (100), 67% for Mn(50), 36% for Zn (50), 31% for Cd (30), 25% for Cu (30), and 43% for Ni (50) during the active growth cycle in HM-amended, extract medium. Results indicate that inoculating the native V. zizanioides with T1B3 strain improves its phytoremediation efficiency of HMs. The mineralogical characteristics of chromite ore tailings and soil were also confirmed by X-ray diffraction, Fourier Transform Infrared, scanning electron microscope-energy dispersive spectroscopy analysis.

Agronomic and economic evaluation of Vetiver grass (Vetiveria zizanioides L.) as means for phytoremediation of diesel polluted soils in Israel

Soil pollution in Israel, due to diesel contamination, is a major concern, with gas stations, factories and refineries being the main polluters (>60%). Vetiver grass (Vetiveria zizanioides L.) is a perennial grass belonging to the Poaceae family, and is recognized world-wide for its potential as a plant with phytoremediation traits to contaminated soils. It is demonstrated here to decrease diesel contamination in field and court-yard trials. Chemical soil analysis indicated up to a 79% decrease (P < .05) in diesel pollution of contaminated soil planted with Vetiver; and at high soil contamination levels of 10 L/m², a significant (P < .05) reduction of 96, 96 and 87% was recorded at soil depths of 0-20, 20-40 and 40-60 cm, respectively. Furthermore, in field plots contaminated with diesel and planted with Vetiver, weeds' biomass recovered to non-polluted levels following 8 to 9 months of Vetiver treatment. An economic evaluation conducted based on the cost-benefit analysis (CBA) principles, utilizing the Net Present Value (NPV) compared phytoremediation to other currently used decontamination procedures. The economic comparison showed that phytoremediation cleanup costs are lower and more beneficial to society at large, primarily from an ecosystem services perspective. Combining the results of the agronomic examination with the economic valuation, this research pointed out that phytoremediation with Vetiver has a non-negligible potential, making it a good solution for cleansing diesel from soils on a state-wide scale in Israel and worthy of further research and development.

A review on moringa tree and vetiver grass - Potential biorefinery feedstocks

Plants and derivatives have been explored for unlimited purposes by mankind, from crop cultivation for providing food and animal feed, to the use for cosmetics, therapeutics and energy. Moringa tree and vetiver grass features, capabilities and applications were explored through a literature review. The suitability of these plants for the bioenergy industry products is evidenced, namely for bioethanol, biogas and biodiesel, given the lignocellulosic biomass content of these plants and characteristics of moringa seed oil. In addition, moringa leaves and pods are an important source for food and animal feed industries due to their high nutrient value. Thus, the co-cultivation of moringa and vetiver could provide energy and food security, and contribute to more sustainable agricultural practices and for the development of rural areas. Policymakers, institutions and scientific community must engage to promote the cultivation of multipurpose crops to cope with energy and food industries competition for biomass.

Effect of wetland plants and bacterial inoculation on dissipation of phenanthrene

This study attempts to evaluate the capacity of wetland plants' ability to dissipate phenanthrene (PHE) under waterlogged conditions. The results indicate that Typha latifolia and Vetiveria zizanioides may efficiently degrade PHE, and were much more effective when under combined plant cultivation with the inoculation of Pseudomonas frederiksbergensis (ATCC BAA-257) . Concentrations of PHE declined from 200 to less than 52 mg kg^-1 in all treatments with plant cultivation. At the end of the experimental period, PHE was undetectable in combined plant cultivation in the presence of bacteria inoculation. Microbial biomass C(carbon), N(nitrogen), and P(phosphate) were significantly different (p < 0.05) in the presence and absence of bacteria inoculation with bacteria inoculation significantly (p < 0.05) increased microbial biomass P. The presence of bacteria inoculation and different plant species significantly (p < 0.05) decreased the PHE concentrations in the microcosms. The inoculation of bacteria and release of exudates from plant roots further enhanced the dissipation of PHE in sand. Concentrations of citric and malic acids were decreased up to 69% in bacteria-inoculated treatments, showing large citric and malic acids serving as a food source and growth substrate for bacteria.

Ethylenediaminedisuccinic acid (EDDS) enhances phytoextraction of lead by vetiver grass from contaminated residential soils in a panel study in the field

Phytoextraction is a green remediation technology for cleaning contaminated soils. Application of chelating agents increases metal solubility and enhances phytoextraction. Following a successful greenhouse experiment, a panel study under field weather elucidated the efficiency of the chelating agent ethylenediaminedisuccinic acid (EDDS) on phytoextraction of lead (Pb) by vetiver grass, a hyperaccumulator of Pb, and a nonaccumulator fescue grass from residential soils contaminated with Pb-based paint from Baltimore, MD and San Antonio, TX. Three soils from each city with Pb content between 1000 and 2400 mg kg^-1 were chosen for the panel study. Sequential extraction revealed that Fe-Mn oxide (60-63%) and carbonate (25-33%) fractions of Pb dominated in Baltimore soils, whereas in San Antonio soils, Pb was primarily bound to the organic fraction (64-70%) because organic content was greater and, secondarily, to the Fe-Mn oxide (15-20%) fraction. Vetiver and fescue grasses were transplanted and grown on wood panels in the field with EDDS applied after 3 months and 13 months. Soil and leachate results indicated that EDDS applications increased Pb solubility in soils. Plant tissues results indicated enhanced the uptake of Pb by vetiver and showed that EDDS application promoted translocation of Pb from root to shoot. Average Pb concentration increased by 53% and 203% in shoots and by 73% and 84% in roots of vetiver after the first and second applications of EDDS, respectively. Concentrations in roots and shoots increased in all tested soils, regardless of soil pH or clay content. After the second application, average Pb concentrations in vetiver were higher than those in fescue by 3.6x in shoots and 8.3x in roots. Visual phytotoxic symptoms from increased bioavailable Pb from EDSS applications were observed in fescue but not in vetiver. This study demonstrated the potential of a chemically-catalyzed phytoremediation system as a cleanup method for lead-contaminated soils.

Effects of Different Soil Amendments on Mixed Heavy Metals Contamination in Vetiver Grass

Three different types of low cost soil amendments, namely, EDTA, elemental S and N-fertilizer, were investigated with Vetiver grass, Vetiveria zizanioides (Linn.) Nash growing under highly mixed Cd-Pb contamination conditions. A significant increase (p < 0.05) in Cd and Pb accumulation were recorded in the shoots of all EDTA and N-fertilizer assisted treatments. The accumulation of Cd in 25 mmol EDTA/kg soil and 300 mmol N/kg soil showed relatively higher translocation factor (1.72 and 2.15) and percentage metal efficacy (63.25 % and 68.22 %), respectively, compared to other treatments. However, it was observed that the increased application of elemental S may inhibit the availability of Pb translocation from soil-to-root and root-to-shoot. The study suggests that viable application of 25 mmol EDTA/kg, 300 mmol N/kg and 20 mmol S/kg soil have the potential to be used for soil amendment with Vetiver grass growing under contaminated mixed Cd-Pb soil conditions.

Modeling BOD and COD removal from Palm Oil Mill Secondary Effluent in floating wetland by Chrysopogon zizanioides (L.) using response surface methodology

While the oil palm industry has been recognized for its contribution towards economic growth and rapid development, it has also contributed to environmental pollution due to the production of huge quantities of by-products from the oil extraction process. A phytoremediation technique (floating Vetiver system) was used to treat Palm Oil Mill Secondary Effluent (POMSE). A batch study using 40 L treatment tanks was carried out under different conditions and Response Surface Methodology (RSM) was applied to optimize the treatment process. A three factor central composite design (CCD) was used to predict the experimental variables (POMSE concentration, Vetiver plant density and time). An extraordinary decrease in organic matter as measured by BOD and COD (96% and 94% respectively) was recorded during the experimental duration of 4 weeks using a density of 30 Vetiver plants. The best and lowest final BOD of 2 mg/L was obtained when using 15 Vetiver plants after 13 days for low concentration POMSE (initial BOD = 50 mg/L). The next best result of BOD at 32 mg/L was obtained when using 30 Vetiver plants after 24 days for medium concentration POMSE (initial BOD = 175 mg/L). These results confirmed the validity of the model, and the experimental value was determined to be quite close to the predicted value, implying that the empirical model derived from RSM experimental design can be used to adequately describe the relationship between the independent variables and response. The study showed that the Vetiver system is an effective method of treating POMSE.

In vitro antioxidant activity of Vetiveria Zizanioides root extract

Free radicals induce numerous diseases by lipid peroxidation and DNA damage. It has been reported that some of the extracts from plants possess antioxidant properties capable of scavenging free radicals in vivo. Vetiveria zizanioides belonging to the family Gramineae, is a densely tufted grass which is widely used as a traditional plant for aromatherapy, to relieve stress, anxiety, nervous tension and insomnia. In this regard, the roots of V zizanioides was extracted with ethanol and used for the evaluation of various in vitro antioxidant activities such as reducing power ability, superoxide anion radical scavenging activity, deoxyribose degradation assay, total antioxidant capacity, total phenolics and total flavonoid composition. The various antioxidant activities were compared with suitable antioxidants such as butyl hydroxy toluene, ascorbic acid, quercetin, alpha tocopherol, pyrocatechol and curcumin respectively. The generation of free radicals O2, H2O2 OH and N O were effectively scavenged by the ethanolic extract of V zizanioides. In all these methods, the extract showed strong antioxidant activity in a dose dependent manner. The results obtained in the present study clearly indicates that V zizanioides scavenges free radicals, ameliorating damage imposed by oxidative stress in different disease conditions and serve as a potential source of natural antioxidant. The study provides a proof for the ethnomedical claims and reported biological activities. The plant has, therefore, very good therapeutic and antioxidant potential.

Activated carbon from vetiver roots: gas and liquid adsorption studies

Large quantities of lignocellulosic residues result from the industrial production of essential oil from vetiver grass (Vetiveria zizanioides) roots. These residues could be used for the production of activated carbon. The yield of char obtained after vetiver roots pyrolysis follows an equation recently developed [A. Ouensanga, L. Largitte, M.A. Arsene, The dependence of char yield on the amounts of components in precursors for pyrolysed tropical fruit stones and seeds, Micropor. Mesopor. Mater. 59 (2003) 85-91]. The N(2) adsorption isotherm follows either the Freundlich law K(F)P(alpha) which is the small alpha equation limit of a Weibull shaped isotherm or the classical BET isotherm. The surface area of the activated carbons are determined using the BET method. The K(F) value is proportional to the BET surface area. The alpha value increases slightly when the burn-off increases and also when there is a clear increase in the micropore distribution width.