Biosorption Parameters Research Articles

Biosorption of Cr (VI) from aqueous solution by extracellular polymeric substances (EPS) produced by Parapedobacter sp. ISTM3 strain isolated from Mawsmai cave, Meghalaya, India

In the current study, EPS producing strain Parapedobacter sp. ISTM3 was isolated from Mawsmai cave, Meghalaya, India. The strain ISTM3 showed enhanced EPS production (4.65 ± 0.10 g L−1) at optimized parameters, i.e., pH 8 and 3% molasses as a carbon source. The extracted EPS was structurally characterized by GC-MS, NMR, and FTIR analysis to investigate its monomer compositions, functional groups, and linkage analysis. GC-MS study confirmed the heteropolymeric nature of EPS, whereas the FTIR study confirmed the presence of an aliphatic group, amine group, uronic acid, and saccharides group in the EPS structure. Biosorption of heavy metals by EPS from an aqueous solution was investigated by using heavy metals mixture (Zn2+, Cu2+, Pb2+, Cr6+, Fe2+, and Cd2+) with 20 mg L−1 concentration of each metal. EPS showed the highest removal efficiency and metal adsorption capability for Cr6+ as compared to other heavy metals studied. Also, metal adsorption capability (19.032 mg g−1) and removal efficiency (95.10%) of Cr6+ by EPS were further increased in acidic conditions (pH 5.0). FTIR and SEM-EDX analysis confirmed the biosorption mechanism of EPS. The Freundlich and Langmuir adsorption isotherms were employed to discover the biosorption parameters for Cr6+ uptake with a concentration range of 10–200 mg L−1 by EPS (1 g L−1). The Langmuir model was found to better fit the Cr6+ adsorption by EPS having a maximum adsorption capacity of 33.783 mg g−1. With this, the present study highlights the EPS production potential of Parapedobacter sp. ISTM3, as well as the potential of extracted EPS for heavy metals removals via adsorption.

Ultrasound-acid modified Merremia vitifolia biomass for the biosorption of herbicide 2,4-D from aqueous solution.

In this work, a biosorbent was prepared by the ultrasound-acid treatment of Merremia vitifolia plant and tested for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D), a phenoxy herbicide. Optimal values of five batch biosorption parameters namely stirring speed, contact time, biosorbent dosage, initial pH and initial adsorbate concentration were experimentally obtained in sequential manner for an enhanced biosorption capacity. The kinetics of the biosorption of 2,4-D were best described by the pseudo first order kinetic model (R2 = 0.99) and the biosorption equilibrium data were successfully fitted to the Langmuir adsorption isotherm (R2 = 0.99) with a maximum biosorption capacity of 66.93 mg g-1. The mechanism of biosorption was investigated using two intraparticle diffusion models (Weber and Boyd), Dubinin-Radushkevich isotherm model and electrostatic interactions. The presence of intraparticle and film diffusion limitations for the biosorption was confirmed along with the physical and chemical nature of the biosorption. The thermodynamic parameters of the biosorption were calculated using the equilibrium data obtained at four different temperatures. The entropy change for biosorption was found to be negative indicating the decreased randomness at the interface. Desorption studies were carried out using different solvents and the percentages of desorption were compared.

The Effect of Temperature on the Biosorption of Dyes from Aqueous Solutions

This work is a review of scientific papers on the influence of temperature (T) on the biosorption of various dyes from aqueous solutions and wastewaters. The dyeing process of textiles is usually carried out at high temperatures, and therefore, the wastewater generated there when entering the treatment plant may still be hot. Hence, depending on the climatic conditions of a given region, the biosorption method used for their purification may occur at various temperatures. Most of the papers clearly stated the positive influence of T on biosorption, generally indicating the chemical nature of this process. At the same time, substantial number of authors confirmed the positive effect of T on the biosorption with an initial T-rise from approximately 20 °C to about 30–40 °C range; conversely, at higher temperatures, they indicated a decrease in the biosorption efficiency. Additionally, many authors clearly implied the negative impact of T on the biosorption parameters. They generally envisaged the physical nature of this process, but also indicated its limitation, as there was only a 15%–50% reduction in biosorption efficiency with an increase in T. In addition, an attempt was made to analyse the effect of temperature on the biosorption process, depending on the type of dye. It could then be cautiously suggested that a moderate increase in the T parameter favourably affected the biosorption of the red and reactive dyes.

Biosorption performance of date palm empty fruit bunch wastes for toxic hexavalent chromium removal

Biosorption ability of date palm empty fruit bunch (DPEFB) was examined for the removal of toxic hexavalent chromium (Cr6+) ions from synthetic wastewater. The pretreated DPEFB biosorbent was studied for its morphology and surface chemistry through Scanning electron microscopy, Energy dispersive elemental analysis and Fourier transform infrared spectroscopy. Effect of biosorption parameters such as pH, biosorbent dosage, contact time, temperature, initial feed concentration and agitation speed on the Cr6+ ions removal efficiency by DPEFB was critically evaluated. The isoelectric point for the DPEFB sorbent was observed at pH 2, above which it was dehydronated to capture the positively charged Cr6+ ions. Batch biosorption studies showed that an optimal chromium removal efficiency of 58.02% was recorded by the DPEFB biosorbent for pH 2, dosage 0.3 g, 100 rpm agitation speed, 120 min contact time, 50 mg/L initial feed concentration and 30 °C operational temperature. Thermodynamic analysis showed that the binding of Cr6+ ions on DPEFB surface was exothermic, stable and favorable at room temperature. Equilibrium behavior of chromium binding on DPEFB was more aligned to Temkin isotherm (R2 = 0.9852) highlighting the indirect interactions between Cr6+ ions and the biosorbent. Kinetic modeling revealed that the biosorption of Cr6+ ions by DPEFB obeyed pseudo-second order model than the pseudo-first order and intra-particle diffusion models. Reusability studies of the DPEFB sorbent showed that NaNO3 was an effective regenerant and the biosorbent can be efficiently reused up to three successive biosorption-desorption cycles for chromium removal. In summary, the results clearly showed that the DPEFB biowaste seems to be an efficient, economic and eco-friendly biosorbent for sustainable removal of toxic hexavalent chromium ions from domestic and industrial wastewater streams.

Optimum Operating Conditions for the Removal of Phosphate from Water Using of Wood-Branch Nanoparticles from Eucalyptus camaldulensis.

A batch bio-sorption experiment was conducted on Eucalyptus camaldulensis Dehnh. wood-branch in the form of woody sawdust nanoparticles (nSD-KF) to evaluate their potential efficiency as phosphate bio-sorption capacity. The operating parameters of phosphate bio-sorption including contact time, initial concentration, pH, temperature, dosage, size, competing ion, and the possible mechanisms responsible for phosphate removal from water were investigated. The nSD-KF were green-synthesized by ball mill grinder and phosphate solutions with various concentrations were performed. The results revealed that the maximum adsorption capacity (qmax) value of nSD-KF was 50,000 µg/g. In addition, the removal efficiency of nSD-KF significantly increased with the increase of initial phosphate concentration, contact time, temperature, and dosage. However, it decreased with the increase of pH and in double-system solution with the presence of ammonium ions. At the application study, the nSD-KF successfully removed 87.82% and 92.09% of phosphate from real agricultural wastewater in a batch experiment and in a column experiment, respectively. Adsorption efficiency of nSD-KF for phosphate increased after the first and second regeneration cycles, but it decreased after the third and fourth cycles. The poor to moderate phosphate desorption from nSD-KF sorbent indicates the stability of phosphate bound to nSD-KF materials. Regardless, biodegradability of nSD-KF-loaded phosphate is possible, and it will be a good source of phosphate to a plant when added to the agricultural soil as a supplemental application of fertilizer. In conclusion, nSD-KF could be considered as a promising lignocellulosic biomaterial used for the removal of phosphate from waters as bio-sorption process.

Enhanced Biosorption of Pb(II) Ions from Aqueous Solutions onto Citric Acid Treated Aspergillus niger Biomass: Equilibrium and Kinetic Studies

In the present study, initially Aspergillus niger was tested for biosorption of Pb(II) ions and then studied the effect of pretreatment for enhanced biosorption. It was found that the maximum biosorption potential was achieved with citric acid treatment (70.56 %) in comparison with the biomass without treatment (65.46 %) at a biosorbent dose of 20 mg/L, pH 4, 100 rpm, 37 ºC for 8 h. The optimized conditions for treated Aspergillus niger were determined by optimizing the biosorption parameters such as pH, temperature, biomass dose, incubation time and agitation speed. This study indicates that the citric acid treated Aspergillus niger is an effective biosorbent for removal of lead (II) at optimized conditions with the maximum biosorption potential of 83.6 % as compared to previous reported work. SEM-EDX and FTIR analysis showed the structural variations and the functional groups involved in lead biosorption, respectively. Biosorption kinetics showed that pseudo second order kinetic model as the better fit.

Biosorption mechanisms of cationic and anionic dyes in a low-cost residue from brewer’s spent grain

ABSTRACT The brewer's spent grain (BSG) is a byproduct of the brewing industry produced in large quantities and with few ecological disposal options. The use of this low-cost residue was investigated for the removal of methylene blue (MB) and tartrazine yellow (TY) dyes. The BSG has been extensively characterized to obtain its physicochemical characteristics. Batch experiments were conducted to investigate the effects of biosorption parameters: initial pH, kinetics, equilibrium isotherms and adsorption thermodynamics. The characterization showed high carbon content and heterogeneous morphology with the presence of meso and macropores. The best experimental conditions were obtained as pH 11 for MB and pH 2 for TY. Kinetics resulted in an equilibrium time of 240 min for MB and 300 min for TY and was best represented by the pseudo-second order model. Different interaction mechanisms were suggested, such as electrostatic interactions, electron donors and electron acceptors, hydrogen bonds, π–π dispersion interactions and the dye molecules aggregation. Equilibrium data were better represented by Langmuir isotherm. The maximum adsorbed amount of MB and TY was 284.75 and 26.18 mg/g, respectively, in each better experimental condition. Through the thermodynamic analysis, it was observed that the adsorption of the dyes was spontaneous and favourable. MB is preferentially retained through chemisorption, whereas TY followed a physical process. Considering the characteristics and results found compared to the recent literature, it was verified that BSG can be used as an effective and innovative biosorbent for removal purposes of dyeing effluent.

Biosorption of copper(II) onto spent biomass of Gelidiella acerosa (brown marine algae): optimization and kinetic studies

This study exclusively focused on the potential application of an inexpensive and sustainable waste macro-algal biomass as an adsorbent for biosorption of copper ions from aqueous medium. After extraction of agar from brown macro-marine algae Gelidiella acerosa, the residual biomass without any further treatment was used as an adsorbent for the expulsion of copper from wastewater. Physicochemical parameters of biosorption like initial pH, initial concentration of Cu(II) solution and biosorbent dosage were optimized using response surface methodology. The maximum copper biosorption potential of 96.36% was observed at optimum conditions of pH of 5.31, initial concentration of 23.87 mg/l and biosorbent dosage of 0.41 g/l. Adopting FTIR and SEM techniques, the surface morphological features of biosorbent were studied. The pseudo-second-order kinetic model was found to be a proper approach to describe biosorption kinetics. All these results confirmed that spent G. acerosa could be considered as an efficient, eco-friendly and economic alternative for Cu(II) removal from aqueous solution.

Biosorption of Rhodamine B onto novel biosorbents from Kappaphycus alvarezii, Gracilaria salicornia and Gracilaria edulis

In the present investigation seaweeds of macroalgae like Kappaphycus alvarezii, Gracilaria salicornia and Gracilaria edulis used as novel biosorbent in native (KA, GS, GE) and ethanol modified (EKA, EGS, EGE) for Rhodamine B (RB) removal from aqueous solution in batch process. Effect of various biosorption parameters such as pH, initial concentration of RB, biosorbent dosage and contact time were studied. The maximum biosorption capacity determined as 9.84 (KA), 11.03 (GS), 8.96 (GE), 112.35 (EKA), 105.26 (EGS) and 97.08 mg/g (EGE), respectively towards the removal of RB from aqueous solutions. Better removal of RB was observed using EKA, EGS, and EGE biosorbents at 2.0 pH. The characterizations of the biosorbents were performed using Scanning Electron microscope and Fourier Transform Infrared Spectroscopy. Biosorption equilibrium data evaluated using Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Jovanovic isotherm model. The Langmuir isotherm model best suited the equilibrium data for all the biosorbents studied. The rate of RB removal subjected to kinetic analysis using pseudo-first-order, pseudo-second-order, intra-particle diffusion and Elovich models. Pseudo-second-order kinetic model better described the experimental data of the RB biosorption. Desorption studies performed using 0.1 M sodium hydroxide as eluting agents for regeneration and recycle analysis. The recyclability of the six biosorbents showed consistent biosorption capacity towards RB removal up to the entire three cycles. The studied biosorbents sourced from large volume and easily available, further biosorption performance indicated that the KA, GS, GE, EKA, EGS and EGE could be used as efficient, alternative and eco-friendly biosorbents for the removal of harmful dyes in the environment.

Biosorption of Acid Red P-2BX by lichens as low-cost biosorbents

ABSTRACTThe aim of this study is to examine the dye biosorption properties of lichen species called Cladonia convoluta and Evernia prunastri. Since lichens are extensively found in the environment, their suitability as a cheap adsorbent has been investigated in this study. The optimal parameters for textile dye biosorption were also determined. The dried lichen biomass showed better dye biosorption capacity than ash lichen biomass. C. convoluta had better dye biosorption capacity than E. prunastri. Dye biosorption rate was found as 71.41% at optimal conditions. This study concluded that C. convoluta was a successful and cheap biosorbent for treatment of water contaminated by Acid Red P-2BX dye.

Screening and identification of bacteria isolated from industrial area groundwater to study lead sorption: Kinetics and statistical optimization of biosorption parameters

Lead contamination in groundwater has raised serious health concerns. The traditional technologies available for lead removal are having several shortcomings. Hence, biosorption is considered as a potential eco-friendly alternative to the existing methods. In the present work, several ground water samples were collected from different lead contaminated regions of III and IV phase of Peenya industrial area from Bengaluru district of Karnataka, India. These ground water samples were used as a source to isolate bacteria with distinct morphological characteristics which were identified as Bacillus toyonensis SCE1, Bacillus anthracis SCE2, Acinetobacter baumannii SCE3, Bacillus toyonensis SCE4 and Bacillus toyonensis SCE5 that were tested for their biosorption properties. The interactive effect of initial lead concentration versus contact time was studied using Response Surface Methodology (RSM) while the biosorbent dosage was kept constant. The biosorption kinetics was investigated for the isolates and the results studies indicated that the biosorption charted pseudo-second order kinetic model and it provided the best fit for the bacterial species for lead biosorption.

Mechanism elucidation and adsorbent characterization for removal of Cr(VI) by native fungal adsorbent

Abstract Mechanism of Cr(VI) bio-removal from mine drainage was studied using a native fungal isolate. The Cr(VI) tolerant species, from chromite mining at Sukinda mine water fungus characterized as Aspergillus fumigatus Fresenius was applied after inactivation in an autoclave, to optimize the parameters of biosorption. Maximum uptake of 48.2 mg Cr(VI) g−1 of inactivated biomass at pH 5.5, 35 °C and 1% sorbent/solution (w/v) ratio was obtained (> 96% sorption) in 120 h from 50 mg L−1 Cr(VI) solution. The chemisorption mechanism involved the functional groups of treated biomass which was elucidated by the Fourier-transform infrared spectroscopy, X-ray powder diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy studies. The XRD phase analysis of the biosorbed material confirmed the limited reduction of Cr(VI) to Cr(III) unlike previous studies. Actual mine drainage containing Cr(VI) and Co(II) was treated with the fungal biomass and was effectively eluted with 0.5 M HCl solution. The study demonstrates the potential application of native fungal isolate to remediate Cr(VI) from the chromite mine drainage.

Analysis of equilibrium, kinetic, and thermodynamic parameters for biosorption of fluoride from water onto coconut (Cocos nucifera Linn.) root developed adsorbent

Abstract Drinking water with higher fluoride levels results in serious irremediable health problems that have attained a startle all over the world. Researches focused towards deflouridation through the application of biosorbents prepared from various plants are finding greater scope and significance. Present research is done on Cocos nucifera Linn. (coconut tree) one of the very commonly available plants throughout Kerala and around the globe. An adsorbent developed from the root portion of C. nucifera Linn. is used in the present study. Equilibrium study revealed that the fluoride uptake capacity is quite significant and linearly increases with initial adsorbate concentration. The adsorption data is analyzed for Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models at varying initial adsorbate concentrations (2–25 mg·L− 1). It is found that the adsorption of fluoride onto C. nucifera Linn. root adsorbent follows Langmuir isotherm. Langmuir isotherm constants “a” and “b” obtained are 2.037 mg·g− 1 and 0.823 L·mg− 1 at an adsorbent dose of 8 g·L− 1 and temperature (26 ± 1) °C. The mean free sorption energy, E obtained, is 9.13 kJ·mol− 1 which points out that the adsorption of fluoride onto C. nucifera Linn. root adsorbent is by chemisorption mechanism. The kinetic study also supports chemisorption with adsorption data fitting well with a pseudo-second-order kinetic model with an estimated rate constant K2 of 0.2935 g·mg− 1 min at an equilibrium contact time of 90 min. The thermodynamic study indicated the spontaneous and endothermic nature (ΔH = 12.728 kJ·mol− 1) of fluoride adsorption onto the C. nucifera Linn. root adsorbent. Scanning Electron Microscopy (SEM), BET, FTIR, and EDX methods were used to analyze the surface morphology of adsorbent before and after fluoride adsorption process. Experiments on deflouridation using C. nucifera Linn. root adsorbent application on fluoride contaminated ground water samples from fields showed encouraging results.

Analysis of Biosorption Parameters, Equilibrium Isotherms and Thermodynamic Studies of Chromium (VI) Uptake by a Nostoc sp. Isolated from a Coal Mining Site in Meghalaya, India

A cyanobacterium isolated from a water sample collected from a coal mine in the West Khasi Hills of Meghalaya, India, and identified as Nostoc sp. (accession no. KX814344) using 16S rRNA analysis showed a high tolerance to chromium. It was shown to be able to grow in the presence of 15 ppm Cr, which is 30 times the highest Cr concentration recorded in the area. Cr biosorption by the cyanobacterium was optimum at pH 6.0 with 3 µg mL−1 biomass. The sorption showed a linear correlation with increasing metal concentration, gradually reaching saturation. An energy dispersive X-ray study verified Cr binding on the cyanobacterial biomass, and FTIR analysis revealed many negatively charged functional groups on the cell surface, which aided in metal binding. Thermodynamic studies showed the biosorption process to be energetically favorable: − 0.479, − 0.665, and − 0.852 kJ mol−1 at temperatures of 293, 303, and 313K, respectively. Sorption isotherm data fit the Langmuir isotherm best, indicating the monolayer nature of the Cr sorption. The organism’s maximum sorption capacity was as high as 20 mg of Cr per g of biomass. The separation factor calculated from the Langmuir isotherm was < 1, signifying favorable interaction between the cyanobacterial biomass and the Cr ions.

Optimization of chromium and tannic acid bioremediation by Aspergillus niveus using Plackett\u2013Burman design and response surface methodology

A chromium and tannic acid resistance fungal strain was isolated from tannery effluent, and identified as Aspergillus niveus MCC 1318 based on its rDNA gene sequence. The MIC (minimum inhibitory concentration) of the isolate against chromium and tannic acid was found to be 200 ppm and 5% respectively. Optimization of physiochemical parameters for biosorption of chromium and tannic acid degradation was carried out by Plackett–Burman design followed by response surface methodology (RSM). The maximum chromium removal and tannic acid degradation was found to be 92 and 68% respectively by A. niveus. Chromium removal and tannic acid degradation was increased up to 11 and 6% respectively after optimization. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate biosorption phenomena.

Applications of Box–Behnken experimental design coupled with artificial neural networks for biosorption of low concentrations of cadmium using Spirulina (Arthrospira) spp.

The present study deals with the application of artificial intelligence techniques coupled with Box–Behnken (BB) design to model the process parameters for biosorption of cadmium using live Spirulina (Arthrospira) spp. as adsorbent in open race way pond with Zarrouk medium. The biomass concentration of Spirulina spp. decreased to half at 4 ppm Cd (II) after 8 days. Based on the LCt50 values, 3.69 ppm (8th day), Spirulina (Arthospira) maxima showed maximum tolerance. Considerable growth and bioaccumulation of Spirulina spp. is observed below 1 ppm and tolerant up to 3 ppm. The cadmium adsorption on Spirulina spp. showed good correlation (R2 = 0.99) when applied to Freundlich equation and data fit into pseudo second order kinetics. A four factorial, three blocks and three level Box–Behnken design with initial concentration (1 ppb to 5 ppb), biosorbant dosage (0.1 gdw to 0.2 gdw), agitation speed (12 rpm to 16 rpm) and pH (6 to 8) as independent variables and percentage adsorption as dependent variable were selected for study. The data were further processed using artificial neural network model and DIRECT algorithm for better optimization. The final Cd (II) concentration of <0.5 ppb was achieved with 1 ppb initial concentration under optimal conditions. A continuous desorption process was also developed for removal of cadmium from Spirulina (Arthrospira) sp.

Biosorption of lac dye by the red marine alga Gracilaria tenuistipitata: biosorption kinetics, isotherms, and thermodynamic parameters

The hypothesis that the dried, ground biomass of the red marine alga Gracilaria tenuistipitata could be used for the efficient removal of lac dye from aqueous solution was assessed in this work. The effects of parameters such as initial pH, biosorbent dosage, contact time, initial dye concentration, and temperature on the biosorption capacity of the dye were investigated. Equilibrium data were analysed using Langmuir, Freundlich, and Temkin isotherm models, and the Freundlich model provided the highest coefficient of determination values. Biosorption kinetic data were successfully described with a pseudo‐second‐order model at initial dye concentrations of 50, 80, 100, and 120 mg l−1. The thermodynamic parameters of biosorption – enthalpy change (∆H° = −30.64 kJ mol−1), free energy change (∆G° = 4.32 kJ mol−1 at 303 K to 7.78 kJ mol−1 at 333 K), and entropy change (∆S° = −115.38 J mol−1 K−1) – were determined. The negative value of the enthalpy change and positive values of the free energy change indicate that the biosorption process is exothermic and non‐spontaneous. The negative value of the entropy change is consistent with decreased randomness at the solid–liquid interface with dye biosorption. Attenuated total reflectance–Fourier transform infrared spectroscopic analysis confirmed the presence of lac dye on the G. tenuistipitata material. The efficiency of lac dye removal by this biomass material at 20 g l−1 and with an initial dye concentration of 50 mg l−1 in acidic solution was 71%, which indicated its potential usefulness as a new dye biosorbent.

Kinetic study of the pyrolysis of pine cone shell through non-isothermal thermogravimetry: Effect of heavy metals incorporated by biosorption

The study concerns the pyrolysis kinetics of exhausted pine cone shell after its use as biosorbent of copper and lead from aqueous solutions in a fixed bed column. First, breakthrough curves of biosorption process were obtained. Main dynamic biosorption parameters were determined and analyzed. Then, non-isothermal thermogravimetric experiments were carried out with raw and metal-loaded biomass in a thermobalance under nitrogen atmosphere at different heating rates. A comparative study was performed. The activation energy dependent on the conversion rate was estimated by Flynn–Wall–Ozawa (a free integral or iso-conventional method) and a mechanistic model (an integral or model-fitting method that considers three independent parallel reactions). The fluctuation of activation energy in Flynn-Wall Ozawa model can be considered the result of thermal degradation reactions of different pseudo-components of the lignocellulosic material (hemicellulose, cellulose and lignin). For raw pine cone shell and metal-loaded-pine cone shell, best fit parameters were determined according to a three independent parallel reactions scheme. The copper and lead present in metal-loaded samples did not modify values of determined parameters which describe the pyrolysis process. Finally, chemical analysis of the chars indicated that about 95% and 99% of copper and lead presented on original waste was recovered in generated chars.

Biosorptive removal of inorganic arsenic species and fluoride from aqueous medium by the stem of Tecomella undulate

Simultaneous removal of fluoride (F−), inorganic arsenic species, AsIII and AsV, from aqueous samples has been performed using an economic indigenous biosorbent (Stem of Tecomella undulata). The inorganic As species in water samples before and after biosorption were determined by cloud point and solid phase extraction methods, while F− was determined by ion chromatography. Batch experiments were carried out to evaluate the equilibrium adsorption isotherm studies for AsIII, AsV and F− in aqueous solutions. Several parameters of biosorption were optimized such as pH, biomass dosage, analytes concentration, time and temperature. The surface of biosorbent was characterized by SEM and FTIR. The FTIR study indicated the presence of carbonyl and amine functional groups which may have important role in the sorption/removal of these ions. Thermodynamic and kinetic study indicated that the biosorption of AsIII, AsV and F− were spontaneous, exothermic and followed by pseudo-second-order. Meanwhile, the interference study revealed that there was no significant effect of co-existing ions for the removal of inorganic As species and F− from aqueous samples (p > 0.05). It was observed that the indigenous biosorbent material simultaneously adsorbed AsIII (108 μg g−1), AsV (159 μg g−1) and F− (6.16 mg g−1) from water at optimized conditions. The proposed biosorbent was effectively regenerated and efficiently used for several experiments, to remove the AsIII, AsV and F− from real water sample collected from endemic area of Pakistan.

Biosorptive Removal of Hexavalent Chromium from Aqueous Industrial Solutions by a Novel Wood Apple Shell Powder Biomass

A novel wood apple shell powder (WASP) biomass was used to remove Cr(IV) from aqueous solutions. Study revealed that WASP removed 50 mg/l of Cr(VI) with &gt;99% efficiency. Optimum parameters for maximum biosorption were: pH 2-4, contact time 60 min and biomass quantity 1g/10 ml. Interestingly, it was observed that loading capacity of WASP was higher as compared to conventional activated charcoal. Equilibrium sorption capacity of WASP increased with increasing initial concentration of Cr(VI) from 5-300 mg/L. Biosorption by WASP conformed to the Langmuir and Freundlich adsorption isotherms. Desorption of Cr(VI) took place with &gt;80% efficiency. Continuous mode study in packed bed column showed that WASP has immense potential as “biomaterial” for the removal/recovery of Cr(VI) from aqueous industrial solutions.