A cradle to cradle approach towards remediation of uranium from water using carbonized arecanut husk fiber

Sustainable materials for remediation of pollutants from water is the need of the hour. In this study two carbonaceous adsorbents prepared through hydrothermal carbonisation and pyrolysis from arecanut husk fiber, an agricultural waste material were used for the adsorption of uranium from water. Batch adsorption data as interpreted using the Langmuir model showed adsorption capacities of 250 mg g^-1 and 200 mg g^-1 respectively at pH 6 for the hydrochar (AHFC) and the pyrochar (AHFT) exceeding that reported for most of the unmodified biochars. The adsorption followed pseudo-second order kinetics and was exothermic in nature. The high selectivity and excellent removal efficiencies on application to environmental ground water samples and good regeneration capacity make these sorbents promising eco-friendly materials for uranium remediation from water.

Prospective application of phosphorylated carbon nanofibers with a high adsorption capacity for the sequestration of uranium from ground water

In this study carbon nanofibers (CNF) were phosphorylated by using ortho-phosphoric acid and applied for adsorptive remediation of uranium from water. The phosphorylated carbon nanofibers (PCNF) showed 96% removal of uranium as compared to 79% by CNF. The adsorption data from batch adsorption studies fitted well with the Langmuir model and a maximum adsorption capacity of 512.8 mg g⁻¹ was obtained at pH 6.0 while the adsorption followed pseudo second order kinetics. A detailed characterisation of the adsorbent has been carried out using various analytical and spectroscopic tools. The application of the adsorbent to ground water samples exhibited promising results even in the presence of other interfering cations and anions which is imperative considering the toxic effects of uranium in ground water.

Adsorption of uranium at pH 6.0 using phosphorylated carbon nanofibers.

Tapping the potential of a glucosamine polysaccharide-diatomaceous earth hybrid adsorbent in the solid phase extraction of a persistent organic pollutant and toxic pesticide 4,4'-DDT from water

A chitosan (a glucosamine polysaccharide)-diatomaceous earth hybrid was studied for the adsorption of 4,4′-dichloro-diphenyl-trichloroethane (4,4′-DDT), a persistent organic pollutant and organochlorine pesticide compound from water. The diverse adsorption process parameters were studied and the modified adsorbent was characterized through XRD, SEM-EDX, FT-IR, XRF, BET and TGA analysis. The concentration of 4,4′-DDT was measured using gas chromatography-tandem mass spectrometry (GC-MS/MS) by adopting a validated analytical procedure. The Langmuir and Freundlich isotherms ascertained the adsorption capacity. The optimum pH and temperature for 4,4′-DDT adsorption were found to be between 5.0 and 7.0 and 20 and 30 °C respectively. Thermodynamic parameters confirmed that the adsorption of DDT on chitosan modified with diatomaceous earth was an exothermic process. The data obtained from kinetics and intra-particle diffusion showed that the composite material is able to sequester 4,4′-DDT and this is reflected in the Langmuir adsorption capacity of 0.968 mg g⁻¹. The adsorbed 4,4′-DDT was successfully eluted with ethyl acetate and recycling studies showed that the modified chitosan can be used for three cycles with significant adsorption performance and this adsorbent proved its efficacy in removing 4,4′-DDT from farm water.

A chitosan (a glucosamine polysaccharide)-diatomaceous earth hybrid was studied for the adsorption of 4,4′-dichloro-diphenyl-trichloroethane (4,4′-DDT), a persistent organic pollutant and organochlorine pesticide compound from water.

1 year follow Up results of "ARTIM HF TRIAL" (angiotensin receptor neprilysin inhibitor effect on TEI index & left ventricular mass in heart failure)

Background

Sacubitril/Valsartan (ARNI) has now class 1 recommendation for treatment of heart failure with reduced ejection fraction (HFrEF). It has been shown to reduce cardiovascular morbidity & mortality in Heart failure with reduced ejection fraction (HFrEF) and significant improvement in all echocardiographic parameters besides TEI index. Tei index is a marker of inflammation, myocardial cell metabolism and its contractile function has not been evaluated as a distinctive entity so we took up this study to evaluate the effects of ARNI on the LV functions using two dimensional (2D)ECHO parameters in Indian population and to assess TEI index for myocardial function.

Methods

256 patients with class II, III or IV HF and EF<40% were enrolled. 171(66.8%) were males and 85(33.2%) were females. Patients were evaluated at baseline, 6 and 12 months for LVEF, LV mass &,LVMPI. Drug was discontinued in 2 patients due to angioedema, in 5 patients due to acute kidney injury and in 2 patients due to hypotension. LV mass measurement done by linear echocardiographic method and Flow Doppler method used for TEI index calculation.

Results

Baseline parameters in 247 patients were mean EF = 26.33 ± 6.28%, mean LV mass = 270.84 ± 68.94 gm, mean Tei Index = 0.852 ± 0.22. ARNI use was associated with an average gradual increase in EF, from a mean baseline of 26.33 ± 6.28% to 33.88 ± 7.73%(p = 0.000001) after 1 year of treatment. There was a significant progressive reduction of 57.97 g/m2 in mean LV mass index after 1 year of treatment (p = 0.000001).TEI index showed significant reduction from baseline mean 0.85 ± 0.22 to 0.70 ± 0.12(p = 0.000001)after 1 year of treatment.

Conclusion

Use of ARNI as additive adjunct to standard care of treatment resulted in significant progressive decline in LV mass and increase in TEI index.

Principal component analysis approach for comprehensive screening of salt stress-tolerant tomato germplasm at the seedling stage

Salt stress is a major abiotic factor that affects the growth and yield of crops. The present study was carried out to assess the salt tolerance among the Arka Samrat, Arka Rakshak, YVU-1, S-22, YVU-2, and PKM-OP tomato germplasms using principal component analysis (PCA). Different salt (NaCl) concentrations like control, 0.04 M, 0.12 M, and 0.20 M were selected in order to classify them into sensitive and tolerant tomato germplasms based on 13 parameters. A significant variation was observed among the selected tomato germplasms towards salinity tolerance at the seedling stage. Shoot length, root length, fresh weight, and dry weight parameters of the seedlings were decreased linearly with an increase in the external NaCl concentration. Salinization of plants has shown to reduce K⁺ content and increase in the Na⁺ accumulation, Ca²⁺, and Catalase activity. Salt stress also increased electrolyte leakage and reduced relative water content of all germplasms. The maximum parameters were less affected in Arka Rakshak and Arka Samrat compared to the remaining germplasms at higher salt stress. The PCA analysis of 13 morphological and physiological variables indicated that Arka Rakshak and Arka Samrat germplasms were salt-tolerant and PKM-OP was susceptible. Thus PCA analysis results are useful for the identification of resistance and sensitive germplasms at the seedling stage.

Improvised method for urinary p-cresol detection and measurement using high performance liquid chromatography/mass spectrometry

Gut microbiota has been implicated in many disorders including Autism Spectrum Disorder (ASD). ASD is a neurodevelopmental brain disorder affecting individuals leading to restricted and repetitive pattern of behaviour and disruption of communication and social interactions. Altered microbiome and the presence or absence of key species capable of affecting specific responses in levels of their fermentation products are reflected in the urinary metabolite profile of patients. The aim of our study is to develop an improvised method for the detection and quantification of urinary p-cresol levels which could serve as an indicator for GI microbial dysbiosis. The p-cresol analysis was achieved using HPLC by a reverse phase C18 column with mobile phase composition of Acetonitrile/water/formic acid (10:90:0.05, v/v/v) in an isocratic mode of elution with a flow rate of 1.0 mL/min. The mass analysis of p-cresol was performed using LC-MS [Triple Quadrupole Liquid Chromatography Mass Spectrometer] in negative ESI mode with electron multiplier detector. p-cresol was eluted at a retention time of approximately 3.4 min. The standard calibration curves had a superior regression coefficient of greater than 0.99 (R² > 0.99) and were linear over a range from 0.0005 mg/mL to 0.015 mg/mL. The method was validated by analysis of six replicates with 0.08% relative standard deviation and method detection and quantification limits were 20 ng/mL and 50 ng/mL respectively. Further validation of method on real urine samples from two groups of children (Control population:< 10 years of age; 5M: 3F and ASD individuals: <10 years of age; All males) showed that detection was effective over a wide range of metabolite at levels as high as 149.73 μg/mL to as low as 0.897 μg/mL. This study reports a rapid, validated and sensitive method for the detection of p-cresol in urine samples.

Confluence of montmorillonite and Rhizobium towards the adsorption of chromium(vi) from aqueous medium

Chromium in its hexavalent oxidation state is carcinogenic and wastewater from the electroplating industry is one of the principal sources of pollution. To reduce this toxicity and pave way towards environmental safety, a combination of environmental microbiology and chemistry is quite efficient for developing biosorbents to sequester chromium from waste water. Immobilization of Rhizobium in sodium montmorillonite provides a conducive environment to capture hexavalent chromium. Various characterization techniques such as FTIR, XPS and SEM-EDAX were performed and batch parameters such as pH variation, adsorbent dosage, concentration of metal ion and temperature were optimized. Pseudo second order kinetics coupled with a higher regression coefficient for Freundlich isotherm and a Langmuir adsorption capacity of 22.22 mg g⁻¹ was achieved for the adsorption process. The adsorption was enhanced by the charge interactions between the protonated clay-Rhizobium surface and Cr(vi) ions in acidic medium. The biosorbent was stable and easily regenerated using NaOH. Preliminary column studies were performed to test the efficiency of the developed biosorbent at higher volumes on a laboratory scale.

Chromium in its hexavalent oxidation state is carcinogenic and wastewater from the electroplating industry is one of the principal sources of pollution.

Identification and Characterization of the microbial communities found in electronic industrial effluent and their potential for bioremediation

Microbial communities are dynamic systems that develop depending on the ecological niche in which they survive. Electronic industry effluent, rich in heavy metals and salts is one such ecosystem where diverse heavy metal resistant microbes exist. Taxonomic identification of this microbial community would be interesting as no information on the microbial diversity from electronic industry effluent is available till date. Our paper attempts to characterize the microbial inhabitants of this niche. Culture dependent microbiological methods were used to establish and identify various microbial species from the effluent. Culture independent methods of identification involving biochemical tests and molecular biology based methods like 16 S- r DNA sequencing and lipid analyses (FAME analysis) were also carried out to confirm the identity of isolated species. Our study, first of its kind revealed the presence of a diverse group of resistant aerobic microbes and disclosed a total of ten bacterial and two fungal isolates. All these isolates were found to survive in presence of heavy metals like cadmium, lead and zinc and were resistant to antibiotics like ampicillin, tetracycline, streptomycin, penicillin and chloramphenicol as indicated by their Minimum Inhibitory Concentrations (MIC). Such resistant isolates harbor possibilities of metal adaptive/selective pathways which render them as economically beneficial bio-sorbent alternatives in bioremediation of heavy metals.

Potential Application of Saccharomyces cerevisiae and Rhizobium Immobilized in Multi Walled Carbon Nanotubes to Adsorb Hexavalent Chromium

The presence of harmful contaminants in the waste stream is an important concern worldwide. The convergence of biotechnology and nanoscience offers a sustainable alternative in treating contaminated waters. Hexavalent chromium, being carcinogenic deserves effective and sustainable methods for sequestration. Here in, we report the immobilization of a prokaryote (Rhizobium) and eukaryote (Saccharomyces cerevisiae) in multiwalled carbon nanotubes (MWCNTs) for the effective adsorption of hexavalent chromium. The carboxylic groups were introduced into the MWCNTs during oxidation using potassium permanganate and were subjected to EDC-HOBT coupling to bind with microbial cell surface. FTIR, TGA, BET, FESEM-EDAX, HRTEM, XPS and confocal microscopy were the investigative techniques used to characterize the developed biosorbents. Experimental variables such as pH, adsorbent dosage, kinetics, isotherms and thermodynamics were investigated and it was observed that the system follows pseudo second order kinetics with a best fit for Langmuir isotherm. Electrostatic interactions between the functional groups in the microbial cell wall and hydrochromate anion at pH 2.0 propel the adsorption mechanism. The lab scale column studies were performed with higher volumes of the Cr(VI) contaminated water. Sodium hydroxide was used as the desorbing agent for reuse of the biosorbents. The sustainable biosorbents show prospects to treat chromium contaminated water.

Effective Adsorption of Precious Metal Palladium over Polyethyleneimine-Functionalized Alumina Nanopowder and Its Reusability as a Catalyst for Energy and Environmental Applications

Palladium is one of the widely used precious metals toward catalysis, energy, and environmental applications. Efficient recovery and reusability of palladium from the spent catalysts is not only highly desirable for sustainable industrial processing but also for preventing environmental contamination. Here, we present a facile citrate-mediated amine functionalization of alumina nanopowder (AO) in aqueous medium. The surface functionalization is probed using infrared (IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, surface area, and zeta potential measurements. The amine-functionalized sorbent is thoroughly studied for its vital palladium-sorption parameters such as amount of adsorbent, pH, adsorption capacity, thermodynamics, and kinetics. The palladium adsorption over amine-functionalized AO is further characterized with X-ray diffraction and XPS. IR analysis of palladium adsorbed over polyethyleneimine is performed to elucidate the mechanistic insight on the role of nitrogen in capturing palladium. The amine-functionalized sorbent after adsorbing palladium is studied for the catalytic reduction of 4-nitrophenol and Cr(VI) and hydrogen generation from ammonia borane, which demonstrated its excellent catalytic activity and reusability toward energy and environmental applications. The environmentally benign materials and all-aqueous reactions employed in this work demonstrate the potential of the strategy for efficient and economical industrial transformations and waste-stream management.

A perspective on diverse adsorbent materials to recover precious palladium and the way forward

A perspective on diverse adsorbent materials for the recovery of palladium.

Mass spectrometric evaluation of neurotransmitter levels in IMR 32 cell line in response to Ayurvedic medicines

RATIONALE

Ayurvedic herbal medicines are administered as part of disease management for many neurodevelopmental disorders like Autism Spectrum Disorder (ASD) and linked comorbid challenges. The biochemistry of the behavioral abnormalities as observed in comorbid conditions is already reported to involve neurotransmitters like gamma-aminobutyric acid (GABA), serotonin (5-HT) and dopamine (DA). The aim of our study is to evaluate the effect of ayurvedic medicines on neurotransmitter levels in IMR 32. Such a study will give some insight into the molecular mechanism of the action of these medicines and help us to understand their contributions in neurotransmitter homeostasis.

METHODS

Solutions of Brahmi, Brahmi vati, Brahmi ghrita and Saraswata ghrita, each at 50 μM, were added to differentiated IMR 32 cells and grown for 24 h. The cell secretion was analysed by ultra-fast liquid chromatography/mass spectrometry (UFLC/MS) in electrospray ionisation (ESI) mode for the neurotransmitters DA, 5-HT and GABA. The mobile phase selected was 0.1% formic acid with 15 μg/mL Na2 -EDTA (A) and 0.1% formic acid in acetonitrile (B) introduced in the ratio of 92:8.

RESULTS

All neurotransmitters under study were eluted within 7 min with GABA eluting at 3.82 min, 5-HT at 4.48 min and DA at 5.47 min, respectively. Linearity was excellent with a correlation coefficient (R(2) ) of 0.999; repeatability and accuracy were also within acceptable range. All herbal drugs evaluated increased the neurotransmitter levels and Brahmi vati increased the neurotransmitter levels to a larger extent.

CONCLUSIONS

Decreased levels of neurotransmitters were observed in behavioral abnormalities which were also observed in children with ASD. Herbal medicines given as part of ayurvedic medicine increased the neurotransmitter levels in IMR 32. Thus, these ayurvedic medicines when prescribed to children with ASD might alleviate the abnormal behavioral symptoms by maintaining neurotransmitter homeostasis. Copyright © 2016 John Wiley & Sons, Ltd.

Primary Intraosseous Mucoepidermoid Carcinoma of the Maxilla

Primary intraosseous mucoepidermoid carcinoma (PIOC) is an infrequent malignancy of the head and neck that exhibits diverse biological behavior. The rareness of the location for a salivary gland tumor and the clinical and radiographic manifestations, suggestive of an odontogenic lesion often pose a diagnostic challenge. We hereby report such a unique case of central mucoepidermoid carcinoma that presented in an ambiguous manner, developing in the maxilla and intruding into the adjacent vital structures, adding a literature review.

Evaluation of the genetic basis of heavy metal resistance in an isolate from electronic industry effluent

Halomonas BVR 1 isolated from an electronic industry effluent had high level of resistance to heavy metals like cadmium, lead, zinc and to various antibiotics. Minimum Inhibitory Concentration (MIC) of the strain toward cadmium and lead was found to be 200 mg L-1 and 400 mg L-1 respectively, while it could tolerate zinc up to 250 mg L-1 and chromium up to 150 mg L-1. The present study proved the genetic contribution of heavy metal resistance in this strain to be plasmid mediated. Isolation of the plasmid from Halomonas BVR 1 and its subsequent linearization with Bam H1 confirmed the presence of a plasmid of size >10 kb. Plasmid curing experiments affirmed plasmid mediated heavy metal resistance. Additionally, genetic transformation of a non metal resistant lab strain Escherichia coli and the cured strain of Halomonas BVR 1 with the isolated plasmid increased their metal tolerance level by 50% confirming the genetic determinant to be present in the plasmid.

An ionic liquid-mesoporous silica blend as a novel adsorbent for the adsorption and recovery of palladium ions, and its applications in continuous flow study and as an industrial catalyst

Aliquat-336@SBA-15 blend adsorbent effectively adsorbs Pd from a spent catalyst.

Prospective application of Aspergillus species immobilized in sodium montmorillonite to remove toxic hexavalent chromium from wastewater

Aspergillus BRVR immobilized in sodium montmorillonite for the effective removal of Cr(vi) from waste water.

A novel ultrasonication method in the preparation of zirconium impregnated cellulose for effective fluoride adsorption

In the present work, we propose for the first time a novel ultrasound assisted methodology involving the impregnation of zirconium in a cellulose matrix. Fluoride from aqueous solution interacts with the cellulose hydroxyl groups and the cationic zirconium hydroxide. Ultrasonication ensures a green and quick alternative to the conventional time intensive method of preparation. The effectiveness of this process was confirmed by comprehensive characterization of zirconium impregnated cellulose (ZrIC) adsorbent using Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray spectrometry (EDX) and X-ray diffraction (XRD) studies. The study of various adsorption isotherm models, kinetics and thermodynamics of the interaction validated the method.

Microwave assisted preparation of n-butylacrylate grafted chitosan and its application for Cr(VI) adsorption

Biopolymers such as chitosan possess excellent properties suited for varied applications. In this work, we describe a novel microwave assisted method for the preparation of n-butylacrylate grafted chitosan adsorbent and its utility for the adsorption of chromium(VI). A 3 min irradiation time was enough to prepare the adsorbent, and techniques such as FT-IR, powder XRD, SEM and EDS were used for comprehensive characterization. The adsorption was effective at pH 3.5 with 25 mL of 20 ppm Cr(VI) solution. Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Elovich and Redlich isotherms were studied in detail. The ΔG, ΔH and ΔS parameters were evaluated to understand the adsorption thermodynamics. The adsorption involves the interaction of Cr(VI) with the hydroxyl and amino groups in chitosan.

Prenatal, perinatal and neonatal risk factors of Autism Spectrum Disorder: a comprehensive epidemiological assessment from India

Incidence of Autism Spectrum Disorder (ASD) is increasing across the globe and no data is available from India regarding the risk factors of ASD. In this regard a questionnaire based epidemiological assessment was carried out on prenatal, perinatal and neonatal risk factors of ASD across 8 cities in India. A retrospective cohort of 942 children was enrolled for the study. 471 children with ASD, under age of 10, were analyzed for pre-, peri-, and neonatal factors and were compared with the observations from equal number of controls. The quality control of the questionnaire and data collection was done thoroughly and the observations were computed statistically. A total of 25 factors were evaluated by unadjusted and adjusted analysis in this study. Among the prenatal factors considered, advanced maternal age, fetal distress and gestational respiratory infections were found to be associated with ASD and had an odds ratio of 1.8. Evaluation of perinatal and neonatal risk factors showed labor complications, pre-term birth, neonatal jaundice, delayed birth cry and birth asphyxia to be associated with ASD with an odds ratio greater than 1.5. This important study, first of its kind in Indian population gives a firsthand account of the relation of pre-, peri- and neonatal risk factors on ASD from an ethnically and socially diverse country like India, the impact of which was unknown earlier. This advocates additional focused investigations on physiological and genetic changes contributed by these risk factor inducing environments.

Effective adsorption of hexavalent chromium through a three center (3c) co-operative interaction with an ionic liquid and biopolymer

Biopolymers as well as ionic liquids are known for their potential applications. In this work, we report the utility of chitosan as an excellent platform for impregnating the ionic liquid, tetraoctylammonium bromide by ultrasonication and its subsequent adsorption for chromium(VI). The effective mass transfer due to sonication coupled with the hydrogen bonding interaction between chitosan-ionic liquid and the electrostatic interaction involving the amino groups in chitosan and hexavalent chromium governs this three center (3c) co-operative mechanism. The adsorption followed a pseudo second order kinetics with a Langmuir adsorption capacity of 63.69 mg g(-1). Various isotherm models were used to correlate the experimental data and the adsorption process is exothermic with a decreased randomness at the solid-solution interface. The thermodynamics of the spontaneous adsorption process could be explained through a positive co-operative effect between the host (chitosan) and the guest (ionic liquid). The adsorbed chromium(VI) could be converted to ammonium chromate using ammonium hydroxide, thereby regenerating the adsorbent. The method could be translated into action in the form of practical application to a real sample containing chromium.

An efficient ultrasound assisted approach for the impregnation of room temperature ionic liquid onto Dowex 1×8 resin matrix and its application toward the enhanced adsorption of chromium (VI)

The work discussed in this paper is based on the utilization of ultrasound in conjunction with an ionic liquid (Aliquat 336) impregnated Dowex 1×8 resin for the effective adsorption of chromium. Ionic liquids are known for their selectivity toward metal extraction and ultrasonic medium offers efficient energy transfer for impregnating the ionic liquid in the resin matrix. The molecular interaction between the ionic liquid impregnated resin and chromium was studied through various physicochemical and spectroscopic techniques. The influence of various analytical parameters on the adsorption of Cr(VI) such as pH, adsorbent dosage, temperature and interference of foreign ions was studied in detail. Chromium (VI) was quantitatively adsorbed in the pH range of 3.5-4, with a high adsorption capacity of 230.9 mg g(-1) in conformity with the Langmuir isotherm model. The study of thermodynamic parameters showed that the adsorption process is exothermic and spontaneous. The adsorbent could be regenerated using 1 mol L(-1) HCl-0.28 mol L(-1) ascorbic acid mixture. Chromium could be effectively detoxified from an industrial effluent and finally the developed method was validated with the analysis of a certified reference material (BCR-715). The obtained results indicated that the ultrasonic assisted impregnation of the room temperature ionic liquid significantly enhances and improves the removal efficiency of Cr(VI).

A preliminary spectroscopic investigation on the molecular interaction of metal-diphenylthiocarbazone complex with cellulose biopolymer and its application

Biopolymer adsorbents are versatile in their application for removal of heavy metals. The present work is focused towards the preliminary study of the interaction of diphenylthiocarbazone (DTZ) complex of chromium(VI) in acidic medium with cellulose biopolymer. Chromium-DTZ complex could be quantitatively adsorbed on a cellulose column in the pH range 1.0-2.5 and the effect of various experimental parameters such as stability of the column and the complex, column breakthrough volume, and interfering ions have been studied in detail. The probable mechanism of adsorption of complex on the cellulose biopolymer was corroborated using Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and solid state 13C nuclear magnetic resonance techniques (CP-MAS). The pores formed due to the hydrogen bond between the cellulose layers and then the ensuing occupation of the complex between these layers and on the surface of the biopolymer layer through electrostatic attractive force and Π interaction of aromatic ring with cellulose are expected to play a vital role in the interaction. The cellulose column could be regenerated using environmentally benign polyethylene glycol-400 (PEG-400) in acidic medium. The cellulose biosorbent has been successfully tested to study the removal of chromium as its dithizone complex from synthetic and real waste water samples.

An enhanced adsorption methodology for the detoxification of chromium using n-octylamine impregnated Amberlite XAD-4 polymeric sorbent

The remediation of heavy metals requires the development of efficient adsorbents. Macroporous polystyrene divinyl benzene based resins are known for their excellent surface characteristics for the effective adsorption of metals. In this paper, we propose an effective adsorption procedure for chromium (VI) using aliphatic primary amine as a guest in Amberlite XAD-4 polymeric sorbent as the host. The adsorption of chromium was quantitative at pH 2.5. The adsorption process was in accordance with pseudo second order kinetics and the maximum adsorption capacity was found to be 75.93 mg g(-1) with good adherence to Langmuir isotherm model. The free energy change ΔG(0) increased with temperature and the negative ΔH(0) and ΔS(0) values indicate the exothermic nature of adsorption and decreased randomness at the adsorbent-solution interface. In aqueous medium, the water molecules surround the hydrophobic host polymeric matrix and this cage effect is responsible for the reduction in entropy of the system. The regeneration of the adsorbent was effective in alkaline medium and the efficacy of the adsorbent was tested for the removal of chromium from tannery waste water.

Value addition of vegetable wastes by solid-state fermentation using Aspergillus niger for use in aquafeed industry

Vegetable waste typically has high moisture content and high levels of protein, vitamins and minerals. Its value as an agricultural feed can be enhanced through solid-state fermentation (SSF). Two experiments were conducted to evaluate the nutritional status of the products derived by SSF of a mixture of dried vegetable waste powder and oil cake mixture (soybean flour, wheat flour, groundnut oil cake and sesame oil cake at 4:3:2:1 ratio) using fungi Aspergillus niger S(1)4, a mangrove isolate, and A. niger NCIM 616. Fermentation was carried out for 9 days at 35% moisture level and neutral pH. Significant (p<0.05) increase in crude protein and amino acids were obtained in both the trials. The crude fat and crude fibre content showed significant reduction at the end of fermentation. Nitrogen free extract (NFE) showed a gradual decrease during the fermentation process. The results of the study suggest that the fermented product obtained on days 6 and 9 in case of A. niger S(1)4 and A. niger NCIM 616 respectively contained the highest levels of crude protein.

Simple and selective extraction process for chromium (VI) in industrial wastewater

A simple and relatively green method has been developed for the determination of chromium based on the extraction of chromium (VI) as its ion-association complex with tetrabutylammoniumiodide (TBAI) in acidic medium. The ion-pair is extracted using isobutylmethylketone (MIBK) as the solvent. The concentration of the extracted chromium (VI) in the organic layer was measured spectrophotometrically at a wavelength maximum of 366 nm and the organic layer was characterized using FT-IR spectroscopy. The influence of various analytical parameters such as pH, aqueous phase volume, equilibration time, interfering ions etc. has been studied in detail. The extracted chromium (VI) was back extracted into the aqueous phase to the non-toxic chromium (III) using ascorbic acid. The calibration graph was linear in the range of 0-2 microg mL(-1) chromium (VI) with a relative standard deviation of 2.4%. A detection limit of 0.25 microg in 25 mL aqueous phase volume could be achieved and the validity of the proposed method has been checked by applying it to synthetic mixtures, spiked water sample, electroplating wastewater and certified reference material BCR-715.

Feasibility of xanthan gum-sodium alginate as a transdermal drug delivery system for domperidone

The present investigation comprises the formulation and in vitro evaluation of domperidone loaded transdermal drug delivery system (TDDS) for controlled release. The polymer membranes were prepared using xanthan gum (XG) and sodium alginate (SA) by varying the blends compositions viz., 10:0, 8:2, 6:4, 5:5, 4:6, 2:8, and 0:10 (XG/SA, wt/wt, %). The drug loaded membranes were evaluated for thickness, content uniformity, tensile behaviours, and in vitro drug release studies. Domperidone was found to be compatible with the prepared formulation as revealed by Fourier transform infrared (FTIR) spectroscopy studies. In vitro release studies were carried out in open glass diffusion cell for a period of 8 h and it showed controlled release of drug from the XG/SA matrix. The present study concludes that, the prepared transdermal films can be used to achieve controlled release of drug and improved bioavailability.

Bio-polymer adsorbent for the removal of malachite green from aqueous solution

A simple, economical and green methodology has been developed for the adsorption of malachite green using cellulose powder as the adsorbent. Batch experimental procedures were conducted to investigate the adsorption ability of this bio-polymer to remove malachite green from aqueous medium. The adsorbed dye on cellulose was characterized by Fourier transform-infrared spectroscopy (FT-IR). The various analytical parameters such as the effect of contact time, pH, temperature, etc. were optimized. The adsorption was efficient at a neutral pH (7.2) and both Langmuir and Freundlich isotherm models showed good fit into the experimental data. The adsorption kinetics indicated that the adsorption proceeds according to pseudo-second-order model. The adsorption of malachite green was found to be exothermic and it was accompanied by decrease in the entropy. Column studies were performed and the regeneration of the adsorbent was done easily using environmentally benign polyethylene glycol-400.

Extractive separation and determination of chromium in tannery effluents and electroplating waste water using tribenzylamine as the extractant

A simple extractive separation method has been developed for the determination of chromium based on the extraction of Cr (VI) as its ion-pair with tribenzylamine (TBA). The ion-pair is extracted at acidic pH using toluene as the diluent. The concentration of chromium in the organic phase was measured spectrophotometrically at 309 nm. The influence of experimental variables such as pH, sample volume, equilibration time, diverse ions etc. has been studied in detail. The extracted chromium (VI) could be stripped to the aqueous phase using NaOH as the stripping agent. The extracts were characterized using FT-IR spectroscopy. A detection limit of 0.08 microg mL(-1) could be achieved and the validity of the method was checked in real tannery effluent, electroplating waste water and spiked water samples.

Spectrophotometric determination of inorganic mercury (II) after preconcentration of its diphenylthiocarbazone complex on a cellulose column

A simple and a relatively green methodology have been developed for the preconcentration of mercury based on the adsorption of its diphenylthiocarbazone complex on a cellulose column. The effects of various parameters such as effect of acidity, eluting agents, stability of the column, sample volume, interfering ions, etc. have been studied in detail. The adsorbed complex could be easily desorbed using environmentally benign polyethylene glycol-400 and the concentration of mercury was determined using visible spectrophotometry. The calibration graph was linear in the range 0-2 microg mL(-1) of mercury with a detection limit of 2 microg L(-1) and the validity of the proposed method was checked by studying the recovery of mercury in spiked tap water, well water and sea water samples. The highest preconcentration factor achieved for quantitative recovery (>95%) of mercury (II) was 33 for a 500mL sample volume. The method was also applied to the analysis of mercury content in city waste incineration ash (CRM176). The relative standard deviation of the method was found to be 3.5%.

Spectrophotometric determination of lead after preconcentration of its diphenylthiocarbazone complex on an Amberlite XAD-1180 column

A simple methodology has been developed for the solid phase extraction of lead based on the adsorption of its diphenylthiocarbazone complex on an Amberlite XAD-1180 column. The effect of various parameters such as eluting agents, stability of the column, sample volume, interfering ions, etc. were studied in detail. The adsorbed complex could be eluted using acetone and the concentration of lead was determined using visible spectrophotometry at a wavelength maximum of 486nm. A detection limit of 3.5microgL(-1) could be achieved and the validity of the proposed method was checked in spiked tap water, well water and industrial wastewater samples. The relative standard deviation of the method was found to be 3.0%. The highest preconcentration factor attainable for quantitative recovery (>95%) of lead was 25 for a 250mL sample volume.

Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column

A method has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on an Amberlite XAD-4 resin column. The influence of acidity, stability of the column, sample volume, flow rate and interfering ions were studied in detail. The adsorbed complex could be eluted using acetone-sulfuric acid mixture and the concentration of chromium was determined using visible spectrophotometry. A detection limit of 6 microg L(-1) could be achieved. A preconcentration factor of 27 could be obtained for 400 mL sample volume. The validity of the method was checked in spiked water samples and electroplating wastewater.

Solid phase extraction of chromium(VI) from aqueous solutions by adsorption of its diphenylcarbazide complex on a mixed bed adsorbent (acid activated montmorillonite-silica gel) column

A novel approach has been developed for the solid phase extraction of chromium(VI) based on the adsorption of its diphenylcarbazide complex on a mixture of acid activated montmorillonite (AAM)-silica gel column. The effect of various parameters such as acidity, stability of the column, sample volume, interfering ions, etc., were studied in detail. The adsorbed complex could be easily eluted using polyethylene glycol-sulfuric acid mixture and the concentration of chromium has been determined using visible spectrophotometry. The calibration graph was linear in the range 0-1microgmL(-1) chromium(VI) with a detection limit of 6microgL(-1). A highest preconcentration factor of 25 could be obtained for 250mL sample volume using glass wool as support for the mixed bed adsorbent. Chromium(VI) could be effectively separated from other ions such as nickel, copper, zinc, chloride, sulfate, nitrate, etc., and the method has been successfully applied to study the recovery of chromium in electroplating waste water and spiked water samples.

Solid phase extraction and spectrophotometric determination of mercury by adsorption of its diphenylthiocarbazone complex on an alumina column

A simple method has been developed for the preconcentration of mercury based on the adsorption of its diphenylthiocarbazone complex on a neutral alumina column. The influence of acidity, eluting agents, stability of the column, sample volume and interfering ions has been investigated in detail. The adsorbed complex could be eluted using environmentally benign polyethylene glycol (PEG 400) and the concentration of mercury was determined by visible spectrophotometry at a wavelength maximum of 520nm. A detection limit of 4microgL(-1) could be achieved and the developed procedure was successfully applied for the determination of mercury in spiked water samples and city waste incineration ash (CRM176). The preconcentration factor attainable for quantitative recovery (>95%) of mercury(II) was 100 for a 1000mL sample volume.