Browsing by Author "S.H. Hasan"

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Agro-industrial waste 'wheat bran' for the biosorptive remediation of selenium through continuous up-flow fixed-bed column
(2010) S.H. Hasan; D. Ranjan; M. Talat
Present study deals with the utilization of an agro-industrial waste wheat bran for the remediation of selenium species, Se(IV) and Se(VI) by continuous up-flow fixed-bed column system. Laboratory-scale column tests were performed to determine potentiality of wheat bran at various bed height, flow rates and initial metal ion concentration and it was found to be very potential biosorbent as it showed good sorption capacities of 72.54μg/g and 62.51μg/g for Se(IV) and Se(VI) respectively. Different models like Bed Depth Service Time (BDST), Thomas and Yoon-Nelson were applied to the experimental sorption data. The data showed very good fit to BDST model and sorption capacities (No) computed using BDST model were 26,664μg/L and 26,400μg/L for Se(IV) and Se(VI) respectively. Also Yoon-Nelson model was found to show good agreement with the experimental kinetic results as compared to the Thomas model. Wheat bran was amenable to efficient regeneration with 10% NaOH. The biosorbent retained most of its original uptake capacity over three cycles of use. The excellent reusability of the biosorbent could lead to development of a viable metal remediation technology. Life factor calculation revealed that biosorbent bed will have sufficient capacity to avoid breakthrough at time t=0 up to 12.17 cycles for Se(IV) and 6.28 cycles for Se(VI) and bed would be completely exhausted after 56.89 cycles for Se(IV) and 18.73 cycles for Se(VI). © 2010 Elsevier B.V.
Application of response surface methodology for the determination of optimum reaction conditions (Temperature and pH) for starch hydrolysis by α-amylase
(2011) Nivedita Jaiswal; Om Prakash; Mahe Talat; S.H. Hasan; Rajesh Kumar Pandey
α-amylase from soybean seeds was purified to apparent homogeneity by affinity precipitation via entrapment in alginate with 84% recovery and about 20-fold purification. The α-amylase activity and stability was characterized at various pH and temperature. Response Surface Methodology (RSM) using two-level-two-factor full factorial Central Composite Design (CCD) model was employed to optimize process parameters like pH and temperature which affects the kinetics of α-amylase catalyzed hydrolysis of starch. The results predicted by the design were found in good agreement (R2 = 97.85%) with the experimental results indicating the applicability of proposed model. The multiple regression Analysis and ANOVA showed the individual and cumulative effect of pH and temperature on enzyme activity indicating that the activity increased with the increase of pH unto 5.5 and temperature 75°C. Thus, the RSM was successful in determining the optimum reaction conditions for starch hydrolysis by α-amylase. © 2011 Academic Journals Inc.
Biosorption of arsenic from aqueous solution using agricultural residue 'rice polish'
(2009) D. Ranjan; M. Talat; S.H. Hasan
'Rice polish' (an agricultural residue) was utilized successfully for the removal of arsenic from aqueous solution. Various parameters viz. pH, biosorbent dosage, initial metal ion concentration and temperature were studied. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models were used and the system followed all three isotherms, showing sorption to be monolayer on the heterogeneous surface of the biosorbent. The maximum sorption capacity calculated using Langmuir model was 138.88 μg/g for As(III) at 20 °C and pH 7.0 and 147.05 μg/g at 20 °C and pH 4.0 for As(V). The mean sorption energy (E) calculated from D-R model indicated chemisorption nature of sorption. Study of thermodynamic parameters revealed the exothermic, spontaneous and feasible nature of sorption process in case of both As(III) and As(V). The pseudo-second-order rate equation described better the kinetics of arsenic sorption with good correlation coefficients than pseudo-first-order equation. Mass transfer, intraparticle diffusion, richenberg and elovich models were applied to the data and it was found that initially the sorption of arsenic was governed by film diffusion followed by intraparticle diffusion. Rice polish was found to be efficient in removing arsenic from aqueous solution as compared to other biosorbents already used for the removal of arsenic. © 2008 Elsevier B.V. All rights reserved.
Biosorption of Cd (II) from water using Citrobacter koseri
(Springer Verlag, 2008) S.H. Hasan; B.N. Bhattacharjee; D. Ranjan; M. Talat
The potentiality of Citrobacter koseri for the removal of Cd (II) from aqueous solution through sorption was tested. The investigation was conducted in batch mode process and the effect of various parameters such as pH, initial Cd(II) concentration, temperature and biomass doses were studied. Thermodynamic parameters revealed that the sorption process was spontaneous, feasible and endothermic. Since the data fitted well to Langmuir model as compared to the Freundlich model this indicates the monolayer sorption on homogeneous surface of sorbent. Kinetics studies showed that the sorption was followed by the pseudo-second order rate expression. © 2008 Springer-Verlag.
Biosorption of Cr(VI) from aqueous solution using A. hydrophila in up-flow column: Optimization of process variables
(2009) S.H. Hasan; P. Srivastava; D. Ranjan; M. Talat
In the present study, continuous up-flow fixed-bed column study was carried out using immobilized dead biomass of Aeromonas hydrophila for the removal of Cr(VI) from aqueous solution. Different polymeric matrices were used to immobilized biomass and polysulfone-immobilized biomass has shown to give maximum removal. The sorption capacity of immobilized biomass for the removal of Cr(VI) evaluating the breakthrough curves obtained at different flow rate and bed height. A maximum of 78.58% Cr(VI) removal was obtained at bed height of 19 cm and flow rate of 2 mL/min. Bed depth service time model provides a good description of experimental results with high correlation coefficient (>0.996). An attempt has been made to investigate the individual as well as cumulative effect of the process variables and to optimize the process conditions for the maximum removal of chromium from water by two-level two-factor full-factorial central composite design with the help of Minitab ® version 15 statistical software. The predicted results are having a good agreement (R 2∈=∈98.19%) with the result obtained. Sorption-desorption studies revealed that polysulfone-immobilized biomass could be reused up to 11 cycles and bed was completely exhausted after 28 cycles. © 2009 Springer-Verlag.
Biosorption of Cr(VI) from water using biomass of aeromonas hydrophila: Central composite design for optimization of process variables
(2009) D. Ranjan; P. Srivastava; M. Talat; S.H. Hasan
The potential use of biomass of Aeromonas hydrophila for biosorption of chromium from aqueous solution was investigated. The variables (pH, initial Cr(VI) concentration, biomass dose, and temperature) affecting process were optimized by performing minimum number of experimental runs with the help of central composite design. The results predicted by design were found to be in good agreement (R2=99.1%) with those obtained by performing experiments. Multiple regression analysis shows that uptake decreases with increase in pH and biomass dose, whereas it increases with increase in temperature and concentration. The maximum removal of Cr(VI) predicted by contour and optimization plots was 184.943 mg/g at pH 1.5, initial Cr(VI) concentration 311.97 mg/L, temperature 60 °C, and biomass dose 1.0 g. The removal of Cr(VI) was governed by adsorption of Cr(VI) as well as its reduction into Cr(III), which further gets adsorbed. The sorption capacity of biomass was calculated from experimental data using Langmuir sorption model and was found to be 151.50 mg/g at 40 °C and pH 1.5, which is comparable to other biosorbents. In addition to this, Dubinin-Radushkevich model was applied, and it was found that nature of sorption was chemisorption. © Humana Press 2008.
Biosorption of lead using immobilized Aeromonas hydrophila biomass in up flow column system: Factorial design for process optimization
(2010) S.H. Hasan; P. Srivastava; M. Talat
Free and immobilized biomass of Aeromonas hydrophila has been utilized for the removal of Pb(II) from aqueous solution. Fitness of Langmuir sorption model to the sorption data indicated the sorption was monolayer and uptake capacity of biomass was 163.9 and 138.88mg/g for the free and immobilized biomass respectively. 85.38% Pb(II) removal was achieved at bed height of 19cm and flow rate of 2mL/min and BDST model was in a good agreement with the experimental results (r2>0.997). An attempt has been made to optimize the process conditions for the maximum removal using Central Composite Design with the help of Minitab® 15 software and the result predicted by optimization plots was 88.27% which is close to the experimental data i.e. 85.38%. Sorption-desorption studies revealed that polysulfone immobilized biomass could reused up to 16 cycles and bed was completely exhaust after 33 cycles. © 2009 Elsevier B.V.
Biosorption of Pb(II) from water using biomass of Aeromonas hydrophila: Central composite design for optimization of process variables
(2009) S.H. Hasan; P. Srivastava; M. Talat
Biomass of Aeromonas hydrophila was successfully utilized for the removal of lead from aqueous solution. The effect of process variables such as pH, initial Pb(II) concentration, biomass dose and temperature on the uptake of lead were investigated using two level four factor (24) full factorial central composite design with the help of MINITAB® version 15 software. The predicted results thus obtained were found to be in good agreement (R2 = 98.6%) with the results obtained by performing experiments. The multiple regression analysis and analysis of variance (ANOVA) showed that the concentration has positive and temperature and biomass dose have negative whereas pH has curved relationship with the uptake of Pb(II). The maximum uptake of Pb(II) predicted by optimization plots was 122.18 mg/g at 20 °C, initial Pb(II) concentration of 259 mg/L, pH 5.0, temperature 20 °C and biomass dose 1.0 g. Langmuir isotherm model was applicable to sorption data and sorption capacity was found to be 163.3 mg/g at 30 °C, pH 5.0 and Pb(II) concentration range 51.8-259 mg/L indicate that the biosorbent was better in comparison of the biosorbent reported in the literature. Dubinin-Radushkevich (D-R) isotherm model was also applied and it was found that sorption was chemisorption (E = 12.98 kJ/mol). FT-IR studies indicate the involvement of various functional groups present on biomass surface in the sorption of Pb(II). © 2009 Elsevier B.V. All rights reserved.
Central composite design for the enzymatic detection of arsenic (III) in aqueous solution from vegetable -waste
(Springer Verlag, 2008) O. Prakash; M. Talat; S.H. Hasan; R.K. Pandey
Urease has been used for the quantitative estimation of As (III) in water. For the parametric optimization of this process Response Surface Methodology was used with the help of two-level-two-full factorial (22), Central Composite Design. Regression coefficient, regression equation and Analysis of Variance (ANOVA) was obtained using MINITAB® 15 software. Predicted values obtained were close to experimental value indicating suitability of model. The 3D Response Surface Plot and Isoresponse Contour Plot were helpful to predict the results by performing only limited set of experiments. Enzyme Urease was extracted from the discarded seeds of pumpkin. It was purified to apparent homogeneity (5.2 fold) by heat treatment at 48±0.1 °C and gel filtration through Sephadex G-200. Effect of As(III) on the activity of homogeneous enzyme preparation (Sp Activity 353 U/mg protein, A 280/A260 = 1.12) was investigated. Inhibition caused by As (III) was non-competitive, irreversible and biphasic. © 2008 Springer-Verlag.
Enzymatic detection of As(III) in aqueous solution using alginate immobilized pumpkin urease: Optimization of process variables by response surface methodology
(2009) Mahe Talat; Om Prakash; S.H. Hasan
Urease immobilized on alginate was utilized to detect and quantify As3+ in aqueous solution. Urease from the seeds of pumpkin (vegetable waste) was purified to apparent homogeneity by heat treatment and gel filtration (Sephadex G-200). Further enzyme was entrapped in 3.5% alginate beads. Urea hydrolysis by enzyme revealed a clear dependence on the concentration and interaction time of As3+. The process variables effecting the quantitation of As3+ was investigated using central composite design with Minitab® 15 software. The predicted results were found in good agreement (R2 = 96.71%) with experimental results indicating the applicability of proposed model. The multiple regression analysis and ANOVA showed that enzyme activity decreased with increase of As3+ concentration and interaction time. 3D plot and contour plot between As3+ concentration and interaction time was helpful to predict residual activity of enzyme for a particular As3+ at a particular time. © 2009 Elsevier Ltd. All rights reserved.
Enzymatic detection of heavy metal ions in aqueous solution from vegetable wastes by immobilizing pumpkin (Cucumis melo) urease in calcium alginate beads
(2008) Om Prakash; Mahe Talat; S.H. Hasan; Rajesh K. Pandey
Enzyme urease is extracted from the discarded seeds of pumpkin. Urease was purified to apparent homogeneity (5.2 fold) by heat treatment at 48 ± 1°C and gel filtration through Sephadex G-200. Effect of model metal ions on the activity of the homogeneous enzyme preparation (sp. activity 353 U/mg protein, A280/A260 = 1.12) of soluble as well as immobilized enzyme was investigated. The soluble and immobilized urease has been used for the quantitative estimation of general water pollution with heavy metal ions like Hg2+, Cu2+, Cd2+, and Co2+. The measurements of the urease residual activity have been carried out in tris-acetate buffer after pre-incubation of model metal salt. The inhibition was found to be biphasic with an initial rapid loss of activity and remainder in slow phase of 10-15 min. The immobilization was done in 3.5% alginate beads leading to 86% of entrapment. There was no leaching of the enzyme over a period of 15 days at 4°C. The beads were fairly stable up to 50°C and exhibited activity even at -10°C. The inhibition by these ions was non-competitive and irreversible, hence could not be restored by dialysis. Based on the values of inhibition constant Ki the heavy-metal ions were found to inhibit urease in the following order Hg2+ > Cu2+ > Cd2+ > Co2+. © KSBB.
Extraction of uranium(VI), plutonium(IV) and some fission products by tri-iso-amyl phosphate
(1997) J.P. Shukla; M.M. Gautam; C.S. Kedari; S.H. Hasan; D.C. Rupainwar
The extractive properties of tri-isoamyl-phosphate (TAP), an indigenously prepared extractant, and the loading capacity of extraction solvent containing TAP for U(VI) and Pu(IV) ions in nitric acid solution have been investigated. The dependence of the distribution ratio on the concentration of nitric acid showed that TAP has an ability to extract these actinides, while the fission product contaminants are poorly extracted. The distribution data revealed a quantitative extraction of both U(VI) and Pu(IV) from moderate nitric acidities in the range 2-7 mol·dm-3. Slope analysis proved predominant formation of the disolvated organic phase complex of the type UO2(NO3)2·2TAP and Pu(NO3)4·2TAP with U(VI) and Pu(IV), respectively. On the contrary he extraction of fission product contaminants such as 144Ce, 137Cs, 95Nb, 147Pr, 106Ru, 95Zr was almost negligible even at very high nitric acid concentrations in the aqueous phase indicating its potential application in actinide partitioning. The recovery of TAP from the loaded actinides could be easily accomplished by using a dilute sodium carbonate solution or acidified distilled water (≃0.01 mol·dm-3 HNO3) as the strippant for U(VI) and using uranous nitrate or ferrous sulphamate as that for Pu(IV). Radiation stability of TAP was adequate for most of the process applications.
Factorial design for the optimization of enzymatic detection of cadmium in aqueous solution using immobilized urease from vegetable waste
(2008) Om Prakash; Mahe Talat; S.H. Hasan; Rajesh K. Pandey
Free as well as alginate immobilized urease was utilized for detection and quantitation of cadmium (Cd2+) in aqueous samples. Urease from the seeds of pumpkin (Cucumis melo), being a vegetable waste, was extracted and purified to apparent homogeneity (Sp. Activity 353 U/mg protein; A280/A260 = 1.12) by heat treatment at 48 ± 0.1 °C and gel filtration through Sephadex G-200. The homogeneous enzyme preparation was immobilized in 3.5% alginate leading to 86% immobilization and no leaching of the enzyme was found over a period of 15 days at 4 °C. Urease catalyzed urea hydrolysis by both soluble and immobilized enzyme revealed a clear dependence on the concentration of Cd2+. The inhibition caused by Cd2+ was non-competitive (Ki = 1.41 × 10-5 M). The time dependent inhibition both in the presence and in absence of Cd2+ ion revealed a biphasic inhibition in the activity. A Response Surface Methodology (RSM) for the parametric optimization of this process was performed using two-level-two-full factorial (22), central composite design (CCD). The regression coefficient, regression equation and analysis of variance (ANOVA) was obtained using MINITAB® 15 software. The predicted values thus obtained were closed to the experimental value indicating suitability of the model. In addition to this 3D response surface plot and isoresponse contour plot were helpful to predict the results by performing only limited set of experiments. © 2008 Elsevier Ltd. All rights reserved.
Green synthesis of gold nanoparticles from Dunaliella salina, its characterization and in vitro anticancer activity on breast cancer cell line
(Editions de Sante, 2019) Ankit Kumar Singh; Ratnakar Tiwari; Vikas Kumar Singh; Prabhakar Singh; Sk Riyazat Khadim; Urmilesh Singh; Laxmi; Vikas Srivastava; S.H. Hasan; R.K. Asthana
An ecofriendly and efficient method (photoinduced) has been used for green synthesis of stable gold nanoparticles (AuNPs) using aqueous extract as a reducing and stabilizing agent, derived from halotolerant microalga Dunaliella salina. Synthesis of AuNPs was confirmed by UV–Vis spectroscopy showing sharp SPR band at 560 nm after 30 min exposure of sunlight. The synthesis was optimized further as exposure(75min) to sunlight, aqueous extract of Dunaliella (AED) inoculum dose(30%) and HAuCl 4 .xH 2 O (1 mM). The presence of nearly spherical shape of AuNPs with average size of 22.4 nm and crystalline nature were confirmed by TEM, SAED and XRD analysis. The XPS analysis of AuNPs showed presence of two individual peaks at 85.17 and 88.94eV that attributed to Au 4f7/2 and Au 4f5/2 respectively. Phycochemical analysis of AED demonstrated presence of phenolics, flavonoids, tannin and proteins. AED when subjected to SDS-PAGE showed protein bands of 92 and 66 KDa. AuNPs were tested for anticancer activity on MCF7 (cancer) and MCF 10A (normal) cell lines, keeping commercial drug cisplatin as positive control. AuNPs selectively killed cancer cells and were not detrimental to the normal cell line whereas cisplatin killed normal cells also at 48 h exposure, therefore, such AuNPs may be used as an anticancer agent. © 2019 Elsevier B.V.
One pot hydrothermal synthesis of fluorescent NP-carbon dots derived from Dunaliella salina biomass and its application in on-off sensing of Hg (II), Cr (VI) and live cell imaging
(Elsevier B.V., 2019) Ankit Kumar Singh; Vikas Kumar Singh; Mamata Singh; Prabhakar Singh; Sk. Riyazat Khadim; Urmilesh Singh; Biplob Koch; S.H. Hasan; R.K. Asthana
The impact of hazardous chemicals and toxic metal ions in the environment played havoc to the ecosystem. In the present work green chemistry approach was applied for one-step hydrothermal synthesis of nitrogen, phosphorus dual doped carbon dots, utilizing green precursor i.e, biomass of halophilic microalgae Dunaliella salina (algal derived nitrogen phosphorous carbon dots i.e A-NPCDs). Synthesized A-NPCDs were characterized through TEM, FT-IR, P-XRD, DLS and XPS. It showed appreciable optical properties with significant fluorescence quantum yield (8%)and exhibited blue color under UV – light (λ ex = 365 nm). A-NPCDs acted as fluorescent turn off sensor for toxic metal ion such as Hg (II) and Cr (VI) with good selectivity and sensitivity. Interestingly, ANPCDs detected Cr (VI) up to 0.018μM which was below the permissible level of Cr (VI) in drinking water. Such sensing resulted because of combination of inner filter effect and dynamic quenching mechanism. Moreover, it also showed good selectivity (0.018μM) for Hg (II) via dynamic quenching mechanism. MTT assay of A-NPCDs on HEK-293 cell line showed biocompatibility with negligible cytotoxicity. Therefore, these were successfully employed for live cell imaging and intracellular detection of Hg (II) and Cr (VI) in HEK-293 cell line. Thus, green synthesized A-NPCDs may be a good alternative for chemically derived CDs in intracellular detection of Hg (II) and Cr (VI) of a complex biological environment. © 2019
Optimization of sorption of Pb (II) from water using rice bran
(Springer Verlag, 2008) S.H. Hasan; D. Ranjan; B.N. Bhattacharjee; M. Talat
Response Surface Methodology (RSM), which is a statistical technique, was used for the optimization of the sorption of Pb (II) from aqueous solution using agricultural waste rice bran. For this purpose a 24 full factorial Central Composite Design (CCD), which is one of the important design of RSM, was utilized to investigate various parameters such as pH, initial [Pb(II)], temperature and biomass dose which are effecting the sorption process. The maximum sorption of Pb (II) was found to be 112.0 mg/ g at 20 °C, pH 5.5, [Pb (II)] 200 mg/L and a biomass dose of 300 mg/50 mL aqueous solution. Multiple regression analysis, 3D response and contour plots and optimization curves were used to further evaluate, confirm and optimize the experimental results. Finally a model was developed for predicting the uptake of Pb (II). The predicted values were found to be in good agreement with the experimental results. Thus the proposed model can be employed for the better removal of Pb (II) with minimum experimental set up. © 2008 Springer-Verlag.
Photo-induced biosynthesis of silver nanoparticles from aqueous extract of Dunaliella salina and their anticancer potential
(Elsevier B.V., 2017) Ankit Kumar Singh; Ratnakar Tiwari; Vijay Kumar; Prabhakar Singh; S.K. Riyazat Khadim; Anupam Tiwari; Vikas Srivastava; S.H. Hasan; R.K. Asthana
The synthesis of silver nanoparticles (AgNPs) via green route, using biological entities is an area of interest, because one of the potential applications in the nanomedicine. In the present study, we have developed photo-induced, ecofriendly, low cost method for biosynthesis of the stable silver nanoparticles using aqueous extract of Dunaliella salina (AED) which act as both reducing as well as stabilizing agent. Biosynthesis of the AgNPs was optimized as: sunlight exposure (30 min), AED (5% (v/v)) and AgNO3 (4 mM). Biosynthesis of AgNPs was monitored by using UV–Vis spectroscopy which exhibited sharp SPR band at 430 nm after 30 min of bright sunlight exposure. SEM and TEM analyses confirmed the presence of spherical AgNPs with average size of 15.26 nm. Crystalline nature of AgNPs was confirmed by SAED and XRD analyses where Braggs reflection pattern at (111), (200), (220) and (311) corresponded to face centered cubic crystal lattice of metallic silver. FTIR analysis revealed the involvement of various functional groups present in AED. AFM analysis confirmed the average surface roughness of synthesized AgNPs as 8.48 nm. AgNPs were also screened for anticancer potential using assay of calcein AM/PI, Annexin/PI and cancer biomarkers against cancer cell line (MCF-7), while normal cell line (MCF-10A) were kept as control. Interestingly, anticancer potential was comparable to the known anticancer drug (Cisplatin), and was not detrimental to the normal cell line. Therefore, such green synthesized AgNPs may be explored as anticancer agent. © 2016 Elsevier B.V.
Removal of basic dyes from aqueous solutions using coconut hard shell powder as a sorbent
(Indian Chemical Society, 2006) J. Pathak; D.C. Rupainwar; M. Talat; S.H. Hasan
The potentiality of sorbent coconut hard shell powder (CHSP) has been investigated as an effective sorbent to removal of malachite green and crystal violet from aqueous solutions. The maximum removal of malachite green and crystal violet have been found at pH 10.5 and 10.2, initial dyes concentration 5 mg L-1 and temperature 30°C, respectively. The effects of different parameters such as contact-time, particle diameter of the sorbent, dyes concentration, pH of the solution and temperature have been investigated.
Removal of Cr(VI) from aqueous solutions using agricultural waste 'maize bran'
(2008) S.H. Hasan; K.K. Singh; O. Prakash; M. Talat; Y.S. Ho
Novel biosorbent 'maize bran' has been successfully utilized for the removal of Cr(VI) from aqueous solution. The effect of different parameters such as contact time, sorbate concentration, pH of the medium and temperature were investigated and maximum uptake of Cr(VI) was 312.52 (mg g-1) at pH 2.0, initial Cr(VI) concentration of 200 mg L-1 and temperature of 40 °C. Effect of pH showed that maize bran was not only removing Cr(VI) from aqueous solution but also reducing toxic Cr(VI) into less toxic Cr(III). The sorption kinetics was tested with first order reversible, pseudo-first order and pseudo-second order reaction and it was found that Cr(VI) uptake process followed the pseudo-second order rate expression. Mass transfer of Cr(VI) from bulk to the solid phase (maize bran) was studied at different temperatures. Different thermodynamic parameters, viz., ΔG°, ΔH° and ΔS° have also been evaluated and it has been found that the sorption was feasible, spontaneous and endothermic in nature. The Langmuir and Freundlich equations for describing sorption equilibrium were applied and it was found that the process was well described by Langmuir isotherm. Desorption studies was also carried out and found that complete desorption of Cr(VI) took place at pH of 9.5. © 2007 Elsevier B.V. All rights reserved.
Rice polish for the removal of arsenic from aqueous solution: Optimization of process variables
(2009) S.H. Hasan; D. Ranjan; M. Talat
Rice polish, a waste from the rice milling industry, was utilized as a potential biosorbent for removal of arsenic from aqueous solution. Optimization of process variables (pH, initial metal concentration, and temperature) and their cumulative effect were investigated using Box-Behnken Design (BBD) with only 15 sets of experimental runs. A second-order polynomial regression model was used, and results predicted showed high value of regression coefficients (R2, i.e., 95.69% for As(III) and 98.42% for As(V)) indicating good agreement with experimental data. The main effect plot showed uptake of arsenic having a curved relationship with pH, initial metal ion concentration having a positive effect, and temperature having a negative effect. The maximum removal of As(III) (41.18 μg/g) and As(V) (49 μg/g) predicted by contour and optimization plot was achieved at pH 6.84 and 4.29, respectively, at an initial metal ion concentration of 1000 μg/L, temperature 20 °C, and biomass dose of 1 g/50 mL. Scanning electron microscopy (SEM) analysis was carried out to find out the changes on the biosorbent surface during the sorption process. © 2009 American Chemical Society.