Coconut shell and husk biochar: A review of production and activation technology, economic, financial aspect and application

Harnessing coconut shell waste: Innovative utilization of activated carbon for effective quantification and decontamination of dioxins in fish oil

Effective management of dioxins and polychlorinated biphenyls (PCBs) in food/feed matrices demands widespread surveillance and innovative decontamination strategies. This study investigates a cost-effective approach using coconut shell-based activated carbon (AC) as an efficient sorbent for two key applications: (i) facilitating the fractionation of dioxins and PCBs during routine analysis to improve surveillance and (ii) decontaminating these pollutants from feed-grade fish oil. The developed AC exhibited enhanced textural characteristics, transitioning from mesoporous to predominantly microporous structure. The adsorption studies unfolded the knowledge gap on congener specific trends, thereby leveraging critical inputs towards process development. The prepared AC was fabricated into a ready-to-use cartridge, compatible with column chromatography-based sample clean-up prior to analyte quantification. The methodology was critically validated according to European Union regulation 644/2017. Notably, the developed decontamination strategy demonstrated 85-100 % efficiency in fortified fish oil samples, with minimal impact on quality parameters, including oxidative stability, fatty acid profile, free fatty acid content and acid value.

Short-Term Alteration of Soil Physicochemical Characteristics Induced by Biochar Application on a Ferric Acrisol

Biochar (incinerated organic waste by-product) has shown promise in enhancing soil fertility and agricultural productivity. Soil quality plays an essential role in the success of agricultural activities, with soil enhancement being crucial for optimizing crop yields and fostering soil fertility. An experiment with different biochar types was arranged in a randomized complete block design. The biochar [coconut husk (CH) biochar and sugarcane bagasse (SB) biochar] was evenly hand mixed with the soil after plowing to 30 cm depth. A one-time application of biochar was done. There was a total of six treatments: SB biochar, SB biochar plus nitrogen (N), phosphorus (P), potassium (K) (SB + NPK), CH biochar, CH biochar plus NPK (CB + NPK), NPK, and control (CT), with three replicates for each treatment. The area of each plot was 3 m2 (3 m × 1 m) to assess the effects of biochar application on the soil physical and chemical characteristics of Ferric Acrisol with cabbage (Fortune F1 variety) as a test crop in Ghana. Soil bulk density, porosity, pH, organic carbon (OC), available N, total P, available K, available calcium (Ca), electrical conductivity (EC), and cation exchange capacity (CEC) were determined. CH and SB addition improved soil bulk density (1.21 g·cm-3 and 1.29 g·cm-3), leading to a significant (p < 0.05) improvement in the total porosity (54.29% and 51.10%), respectively, at 0-30 cm soil depth compared to the presoil condition (1.5 g·cm-3). Additionally, CH and SB significantly (p < 0.05) impacted the soil chemical characteristics and fertility of the tested soil. The results showed that biochar application is crucial for C sequestration, reduction in pH (SB-7.36 and CH-7.44 compared to the presoil condition (4.93) at 0-30 cm soil depth), and soil fertility enhancement. Applying biochar to soils can therefore be considered a potential solution to improve soil fertility for sustainable crop production.

Sustainable synthesis and advanced optimization of Prosopis juliflora biomass catalyst for efficient biodiesel production and environmental impact assessment

The present research focuses on developing an innovative biochar-based heterogeneous catalyst from Prosopis Juliflora biomass waste using response surface methodology and genetic algorithm (GA) to optimize pyrolysis parameters, achieving a 46.31% PJBC yield from 60 mg of biomass at 790 °C for 60 min. The pyrolyzed PJBC is characterized using SEM, FTIR, XRD, EDX, BET, XPS analyses, and physico-chemical measurements to confirm its catalytic activity. Now, the newly synthesized PJBC serves as an efficient catalyst for waste Trichosanthes cucumerina seed biodiesel (WTSB) production from waste Trichosanthes cucumerina seed bio-oil through trans-esterification, achieving a maximum yield of 97.42%. Also, the WTSB exhibits excellent physico-chemical properties that meet most of the ASTM D6751 standards for biodiesel and closely align with the characteristics of conventional diesel fuel. Therefore, this research utilized neat WTSB and WTSB/diesel blends (WTSB25, WTSB50, and WTSB75) in a direct injection (DI) diesel engine at variable load settings. Among all WTSB blends, the WTSB25 blend showed closer variations of 1.65% lower BTE and 9.29% higher BSEC when compared to conventional diesel fuel readings. Its peak in-cylinder pressure and heat release rate were similar to those of diesel fuel at 100% engine load. Emission analysis indicated that the WTSB25 reduced specific HC, CO, and smoke opacity emissions by 8.39%, 13.97%, and 4.18%, respectively. However, specific NO emissions increased slightly by 3.05% compared to diesel fuel. Thus, WTSB25 is validated as a viable diesel alternative requiring no significant engine modifications. The environmental impact, lifecycle and economic feasibility are also discussed.

Impacts of sugarcane bagasse-derived biochar and apatite on heavy metal speciation in incubated heavy metal-contaminated soil

Heavy metal contamination in soils poses significant environmental and health risks, necessitating effective remediation strategies. This study investigates the time-dependent effects of sugarcane bagasse-derived biochar and apatite as soil amendments on the chemical speciation of heavy metals in polluted soil. Despite their known efficacy, the specific influence of these amendments on the distribution of heavy metal chemical fractions over time remains underexplored. Incubated experiments were conducted over one month using soil samples spiked with Biochar and apatite. Pb- and Zn-contaminated soils were incubated with biochar and apatite at varying ratios: biochar at 5% and 10%, and biochar/apatite mixtures at 2.5:2.5% and 5:5% ratios (in mass). Changes in heavy metal speciation were analyzed using Tessier's sequential extraction procedure. Results demonstrate significant shifts in the distribution of heavy metals across soil phases, suggesting potential reductions in bioavailability and environmental mobility. Incubation with varying application rates of biochar and apatite revealed diverse effects on Pb and Zn chemical fractions. Amendments reduced the exchangeable fraction of Pb and Zn by up to 38.5% and 47.7%, respectively, while increasing their more stable F4 and F5 fractions. Proposed mechanisms likely include cation exchange (swapping of ions between the soil and amendments), precipitation (formation of solid compounds), complexation with functional groups/minerals, and physical adsorption (attachment of metal ions) on biochar surfaces The efficacy of biochar and apatite underscores their promise for remediating Pb and Zn in contaminated soils, though variability in efficacy across different soil types warrants further investigation. These findings indicate the potential for practical applications in large-scale soil remediation projects. Further research is needed to assess the persistence of heavy metal stabilization over time and under varying environmental conditions.

Assisted Phytoremediation between Biochar and Crotalaria pumila to Phytostabilize Heavy Metals in Mine Tailings

The increasing demand for mineral resources has generated mine tailings with heavy metals (HM) that negatively impact human and ecosystem health. Therefore, it is necessary to implement strategies that promote the immobilization or elimination of HM, like phytoremediation. However, the toxic effect of metals may affect plant establishment, growth, and fitness, reducing phytoremediation efficiency. Therefore, adding organic amendments to mine tailings, such as biochar, can favor the establishment of plants, reducing the bioavailability of HM and its subsequent incorporation into the food chain. Here, we evaluated HM bioaccumulation, biomass, morphological characters, chlorophyll content, and genotoxic damage in the herbaceous Crotalaria pumila to assess its potential for phytostabilization of HM in mine tailings. The study was carried out for 100 days on plants developed under greenhouse conditions under two treatments (tailing substrate and 75% tailing/25% coconut fiber biochar substrate); every 25 days, 12 plants were selected per treatment. C. pumila registered the following bioaccumulation patterns: Pb > Zn > Cu > Cd in root and in leaf tissues. Furthermore, the results showed that individuals that grew on mine tailing substrate bioaccumulated many times more metals (Zn: 2.1, Cu: 1.8, Cd: 5.0, Pb: 3.0) and showed higher genetic damage levels (1.5 times higher) compared to individuals grown on mine tailing substrate with biochar. In contrast, individuals grown on mine tailing substrate with biochar documented higher chlorophyll a and b content (1.1 times more, for both), as well as higher biomass (1.5 times more). Therefore, adding coconut fiber biochar to mine tailing has a positive effect on the establishment and development of C. pumila individuals with the potential to phytoextract and phytostabilize HM from polluted soils. Our results suggest that the binomial hyperaccumulator plant in combination with this particular biochar is an excellent system to phytostabilize soils contaminated with HM.

Coconut shell-based biochars produced by an innovative thermochemical process for obtaining improved lignocellulose-based adsorbents

The urgent need for a simple and cost-effective thermochemical process to produce biochar has prompted this study. The aim was to develop a straightforward thermochemical process under O2-limited conditions for the production of coconut-based biochar (CBB) and to assess its ability to remove methylene blue (MB) through adsorption, comparing it with CBB produced by slow pyrolysis. CBBs were obtained under different atmospheric conditions (O2-limited, muffle furnace biochar (MFB); and inert, pyrolytic reactor biochar (PRB)), at 350, 500, and 700 °C, and for 30 and 90'. MFB and PRB were characterized using FTIR, RAMAN, SEM, EDS, and XRD analyses. Adsorption tests were conducted using 1.0 g L-1 of MFB and PRB, 10 mg L-1 of MB at 25 °C for 48 h. Characterization revealed that atmospheric conditions significantly influenced the yield and structural features of the materials. PRB exhibited higher yields and larger cavities than MFB, but quite similar spectral features. Adsorption tests indicated that MFB and PRB had qt values of 33.1 and 9.2 mg g-1, respectively, which were obtained at 700 °C and 90', and 700 °C and 30', respectively. This alternative method produced an innovative and promising lignocellulose-based material with great potential to be used as a biosorbent.

A Review Delving into the Factors Influencing Mycelium-Based Green Composites (MBCs) Production and Their Properties for Long-Term Sustainability Targets

Mycelium-based green composites (MBCs) represent an eco-friendly material innovation with vast potential across diverse applications. This paper provides a thorough review of the factors influencing the production and properties of MBCs, with a particular focus on interdisciplinary collaboration and long-term sustainability goals. It delves into critical aspects such as fungal species selection, substrate type selection, substrate preparation, optimal conditions, dehydrating methods, post-processing techniques, mold design, sterilization processes, cost comparison, key recommendations, and other necessary factors. Regarding fungal species selection, the paper highlights the significance of considering factors like mycelium species, decay type, hyphal network systems, growth rate, and bonding properties in ensuring the safety and suitability of MBCs fabrication. Substrate type selection is discussed, emphasizing the importance of chemical characteristics such as cellulose, hemicellulose, lignin content, pH, organic carbon, total nitrogen, and the C: N ratio in determining mycelium growth and MBC properties. Substrate preparation methods, optimal growth conditions, and post-processing techniques are thoroughly examined, along with their impacts on MBCs quality and performance. Moreover, the paper discusses the importance of designing molds and implementing effective sterilization processes to ensure clean environments for mycelium growth. It also evaluates the costs associated with MBCs production compared to traditional materials, highlighting potential cost savings and economic advantages. Additionally, the paper provides key recommendations and precautions for improving MBC properties, including addressing fungal strain degeneration, encouraging research collaboration, establishing biosecurity protocols, ensuring regulatory compliance, optimizing storage conditions, implementing waste management practices, conducting life cycle assessments, and suggesting parameters for desirable MBC properties. Overall, this review offers valuable insights into the complex interplay of factors influencing MBCs production and provides guidance for optimizing processes to achieve sustainable, high-quality composites for diverse applications.

New porous amine-functionalized biochar-based desiccated coconut waste as efficient CO2 adsorbents

Climate change caused by the greenhouse gases CO2 remains a topic of global concern. To mitigate the excessive levels of anthrophonic CO2 in the atmosphere, CO2 capture methods have been developed and among these, adsorption is an especially promising method. This paper presents a series of amine functionalized biochar obtained from desiccated coconut waste (amine-biochar@DCW) for use as CO2 adsorbent. They are ethylenediamine-functionalized biochar@DCW (EDA-biochar@DCW), diethylenetriamine-functionalized biochar@DCW (DETA-biochar@DCW), triethylenetetramine-functionalized biochar@DCW (TETA-biochar@DCW), tetraethylenepentamine-functionalized biochar@DCW (TEPA-biochar@DCW), and pentaethylenehexamine-functionalized biochar@DCW (PEHA-biochar@DCW). The adsorbents were obtained through amine functionalization of biochar and they are characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA). The CO2 adsorption study was conducted isothermally and using a thermogravimetric analyzer. From the results of the characterization analyses, a series of amine-biochar@DCW adsorbents had larger specific surface area in the range of 16.2 m2/g-37.1 m2/g as compare to surface area of pristine DCW (1.34 m2/g). Furthermore, the results showed an increase in C and N contents as well as the appearance of NH stretching, NH bending, CN stretching, and CN bending, suggesting the presence of amine on the surface of biochar@DCW. The CO2 adsorption experiment shows that among the amine modified biochar adsorbents, TETA-biochar@DCW has the highest CO2 adsorption capacity (61.78 mg/g) when using a mass ratio (m:m) of biochar@DCW:TETA (1:2). The adsorption kinetics on the TETA-biochar@DCW was best fitted by the pseudo-second model (R2 = 0.9998), suggesting the adsorption process occurs through chemisorption. Additionally, TETA-biochar@DCW was found to have high selectivity toward CO2 gas and good reusability even after five CO2 adsorption-desorption cycles. The results demonstrate the potential of novel CO2 adsorbents based on amine functionalized on desiccated coconut waste biochar.

Comparative Transcriptome Analysis Provides Insights into the Effect of Epicuticular Wax Accumulation on Salt Stress in Coconuts

The coconut is an important tropical economical crop and exhibits high tolerance to various types of salinity stress. However, little is known about the molecular mechanism underlying its salt tolerance. In this study, RNA-Seq was applied to examine the different genes expressed in four coconut varieties when exposed to a salt environment, resulting in the generation of data for 48 transcriptomes. Comparative transcriptome analysis showed that some genes involved in cutin and wax biosynthesis were significantly upregulated in salt treatment compared to the control, including CYP86A4, HTH, CER1, CER2, CER3, DCR, GPAT4, LTP3, LTP4, and LTP5. In particular, the expression of CER2 was induced more than sixfold, with an RPKM value of up to 205 ten days after salt treatment in Hainan Tall coconut, demonstrating superior capacity in salt tolerance compared to dwarf coconut varieties. However, for yellow dwarf and red dwarf coconut varieties, the expression level of the CER2 gene was low at four different time points after exposure to salt treatment, suggesting that this gene may contribute to the divergence in salt tolerance between tall and dwarf coconut varieties. Cytological evidence showed a higher abundance of cuticle accumulation in tall coconut and severe damage to cuticular wax in dwarf coconut.

Coconut waste valorization to produce biochar catalyst and its application in cellulose-degrading enzymes production via SSF

Solid waste management and waste valorization are key concerns and challenges around the globe. Solid wastes generated by food industries are found in a diverse variety, are key sources of enormously valuable compounds, and can be effectively transformed into useful products for broad industrial applications. Biomass-based catalysts, industrial enzymes, and biofuels are some of the very prominent and sustainable products that are developed using these solid wastes. The aims of the current study are therefore centered on the multiple valorizations of coconut waste (CWs) to develop biochar as a catalyst and its application in fungal enzyme production in solid-state fermentation (SSF). Biochar as a catalyst using CWs has been prepared via a calcination process lasting 1 h at 500 °C and characterized through X-ray diffraction, Fourier-transformed infrared spectroscopy, and scanning electron microscope techniques. The produced biochar has been implemented for boosting enzyme production through SSF. In addition, studies have been performed on enzyme production with varying time and temperature, and it is found that the maximum 92 IU/gds BGL enzyme could be produced at a 2.5 mg concentration of biochar-catalyst at 40 °C in 72 h.