Surface modified bacterial biosorbent with poly(allylamine hydrochloride): Development using response surface methodology and use for recovery of hexachloroplatinate(IV) from aqueous solution.
ABSTRACT In this study, poly(allylamine hydrochloride) (PAA/HCl) was cross-linked with fermentation bacterial waste (Escherichia coli) in order to introduce a large amount of amine groups as binding sites for potassium hexachloroplatinate(IV), as a model anionic pollutant. The sorption performance of PAA/HCl-modified E. coli was greatly affected by the dosages of PAA/HCl and crosslinker (epichlorohydrin, ECH), and by the pH of the modification reaction medium. These factors were optimized through the response surface methodology (RSM). A three-level factorial Box-Behnken design was performed, and a second-order polynomial model was successfully used to describe the effects of PAA/HCl, ECH and the pH on the Pt(IV) uptake (R(2) = 0.988). The optimal conditions that were obtained from the RSM were 0.49 g of PAA/HCl, 0.05 mL of ECH and pH 10.02, with 1.0 g of dried E. coli biomass. The biosorption isotherm and kinetics studies were carried out in order to evaluate the sorption potential of the PAA/HCl-modified E. coli that was prepared under the optimized conditions. The sorption performance of the developed bacterial biosorbent was 4.36 times greater than that of the raw E. coli. Desorption was carried out using 0.05 M acidified thiourea and the biosorbent was successfully regenerated and reused up to four cycles. Therefore, this simple and cost-effective method suggested here is a useful modification tool for the development of high performance biosorbents for the recovery of anionic precious metals.
SourceAvailable from: Yeoung-Sang Yun[Show abstract] [Hide abstract]
ABSTRACT: Biosorption is a promising technology not only for the removal of heavy metals and dyes but also for the recovery of precious metals (PMs) from solution phases. The biosorptive recovery of PMs from waste solutions and secondary resources is recently getting paid attractive attention because their price is increasing or fluctuating, their available deposit is limited and maldistributed, and high-tech industries need more consumption of PMs. The biosorbents for recovery of PMs require specifications which differ from those for the treatment of wastewaters containing heavy metals and dyes. In this review, the previous works on biosorbents and biosorption for recovery of PMs were summarized. Especially, we discuss and suggest the required specifications of biosorbents for recovery of PMs and strategies to give the required properties to the biosorbents. We believe this review will provide useful information to scientists and engineers and hope to give insights into this research frontier.Bioresource Technology 02/2014; 160. DOI:10.1016/j.biortech.2014.01.121 · 5.04 Impact Factor
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ABSTRACT: In this study, the cationic bacterial biosorbent, poly(allylamine hydrochloride) (PAA/HCl)-modified Escherichia coli, was successfully immobilized as a chitosan fiber, which was proved to be a sustainable biosorbent for platinum removal and recovery from aqueous solutions in batch and column systems. Compared to the commercial ion exchange resins, PAA/HCl-modified E. coli chitosan fiber showed a quite good performance for Pt(IV) removal. Two-parameter (Langmuir and Freundlich) and three-parameter (Sips and Redlich–Peterson) models were employed to describe the batch isotherm experimental data. Among these four models, the Redlich–Peterson model fit best, with higher coefficient of determination, chi-square and average percentage error values. Thermodynamic parameters (ΔG0 < 0 and ΔH0 > 0) showed the spontaneity and endothermic nature of biosorption process. The kinetics of Pt(IV) biosorption with different initial concentrations were better fit by the pseudo-second-order model, with higher coefficient of determinations and more closely predicted qe values. An acidified 0.005 M thiourea was used to regenerate platinum from exhausted biosorbent maintaining desorption efficiencies over 90.2% until five cycles. In the column studies, the breakthrough curve showed a typical S-shaped curve, with breakthrough and exhaustion times appearing at 36.0 h and 52.5 h, respectively, which was opened up a possibility of column regeneration.Separation and Purification Technology 03/2015; 143. DOI:10.1016/j.seppur.2015.01.023 · 3.07 Impact Factor
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ABSTRACT: Investigation of the performance of a lint camera system in identifying lint using image analysis Optimization of AOX formation during the first chlorine dioxide bleaching stage (D 0) of soda AQ bagasse pulp Determination of the contribution of penetration, diffusion and alkali consumption in the impregnation of Eucalyptus grandis chips Mild steam explosion followed by kraft cooking and oxygen delignification of spruce (Picea abies) Optical characterisation of size, shape and fibrillarity from microfibrillar and microcrystalline cellulose, and fine ground wood powder fractions October -December 2013 Volume 66 Number 4Appita Journal 10/2013; 66(4):306-312. · 0.27 Impact Factor