The removal of Cd (II) from industrial wastewater by macrofungus Pleurotus platypus was investigated in a fixed bed column. Experiments were conducted to study the effect of important parameters such as bed depth (5-15cm) and flow rate (5-15mlmin-1). The bed depth service time model (BDST) fitted well with the experimental data and the adsorption capacity (N0) estimated from this model was 2418.12mgL-1. The effect of co-ions on adsorption of cadmium (II) was analyzed as single and multimetal systems. The breakthrough and exhaustion points were found to be earlier for biosorption of cadmium (II) in the presence of co-ions. The biosorbent was employed for the treatment of industrial effluent in a continuous column mode and its reusability was assessed. The column was regenerated by eluting cadmium (II) using 0.01M HCl and the adsorbent was reused for three sorption-desorption cycles without considerable loss in biosorption capacity. In the three cycles of biosorption, about 3.6L of industrial effluent could be treated to reach the Cd (II) standard (0.1mgL-1) established by the Central Pollution Control Board (CPCB). P. platypus proved to be the potential biosorbent for the removal of Cd (II) from industrial effluents. © 2011 Elsevier B.V.

Vimala R

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Nilanjana Mitra

Charumathi D

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

Desalination

In the present study, response surface methodology (RSM) employing Box-Behnken design was used to optimize the parameters for biosorption of praseodymium(III) onto biowaste materials viz., crab shell (C{\textless}inf{\textgreater}R{\textless}/inf{\textgreater}S) and orange peel (OP). Various process parameters viz., pH (A: 3.0-9.0), biomass dosage (B: 0.05-0.35g/L), initial metal concentration (C: 50-350mg/L), temperature (D: 20-60°C) and contact time (E: 5-60min) were chosen for optimization. A square root transformation was suggested by the Box-Cox plot in the present case. A low p-value of {\textless}0.0001 validated the significance of the model. Maximum Pr(III) uptake of 57.8mg/g for (C{\textless}inf{\textgreater}R{\textless}/inf{\textgreater}S) and 49.9mg/g for OP was noted under optimum conditions. Among the equilibrium isotherms tested, Langmuir was found to be the best fitted model suggesting a homogeneous mode of biosorption for both the biosorbents. Kinetic studies showed better applicability of pseudo-first order model for C{\textless}inf{\textgreater}R{\textless}/inf{\textgreater}S suggesting physisorption and pseudo-second order model for OP confirming chemisorption as phenomena underlying the process. SEM analysis confirmed the homogeneous mode of biosorption. FTIR studies confirmed the involvement of amine, alcohol, ketone and amide groups in the process of Pr(III) biosorption onto C{\textless}inf{\textgreater}R{\textless}/inf{\textgreater}S and OP. Regeneration studies suggested that the biosorbents could be consistently reused upto 7 cycles with a minor metal leaching of 0.97{\%} and 0.89{\%}.

Ecological Engineering

Optimization of parameters for praseodymium(III) biosorption onto biowaste materials using response surface methodology: Equilibrium, kinetic and regeneration studies

The potential of an adsorption coupled reduction process for removal of chromium(VI) was evaluated using immobilized algal consortium (of fresh water isolates, Oocystis, Nostoc, Syncoccus and Desimococcus species) through batch reactor studies. The batch sorption capacity of algae was substantially enhanced on adaptation to Cr(VI) and consortium formation (83.53 mg/g). The batch data followed Langmuir isotherm and pseudo first order kinetics. The effective applicability of the sorbent for Cr(VI) removal was tested in packed bed column reactor. At the adsorbent dosage of 1 g/L, flow rate of 3 mL/min, bed height of 20 cm and initial Cr(VI) concentration of 300 mg/L, maximum adsorption capacity of 579.2 mg/g was achieved. The possible mechanism of adsorption and reduction of Cr(VI) was explained by Fourier transform infrared spectroscopy and electron paramagnetic resonance spectroscopy analysis confirmed the reduction of Cr(VI) to Cr(III) on the sorbent surface.

Fulltext

Asian Journal of Chemistry

Removal of Cr(VI) by Immobilized Consortium of Freshwater Microalgae in Batch and Continuous System

In the present study, response surface methodology employing 5-level Box-Behnken design was used to optimize the biosorption of Zn(II) onto macrofungus Pleurotus platypus. Various process parameters, viz., pH (A: 2-8), biomass dosage (B: 0.5-2.5. g/L), initial metal concentration (C: 50-450. mg/L), temperature (D: 10-70. °C) and time (E: 2-24. h) were chosen for optimization. A natural log transformation was suggested by the Box-Cox plot in the present case. A low p-value of &lt;0.0001 validated the significance of the model. Maximum Zn(II) uptake of 135.1. mg/g was noted at pH 5, biomass dosage 1.5. g/L, initial metal concentration 250. mg/L, temperature 40. °C and time 18.5. h. Among the equilibrium isotherms tested, Freundlich was found to be the best fitted one suggesting a heterogeneous mode of biosorption. Kinetic studies showed better applicability of pseudo-second order model suggesting chemisorption as phenomena underlying the process. SEM analysis confirmed the heterogeneous mode of biosorption. FTIR studies confirmed the involvement of amine, alcohol, ketone and carboxylate groups in the process of Zn(II) biosorption onto P. platypus. Regeneration studies suggested that the biosorbent could be consistently reused up to 5 cycles with a minor metal leaching of 0.92%. © 2013 Elsevier B.V.

Biosorption of Zn(II) onto Pleurotus platypus: 5-Level Box–Behnken design, equilibrium, kinetic and regeneration studies

For the past few decades, biosorption has been widely investigated for the removal of different contaminants in aqueous media. A number of biomasses of different genre have been identified to possess good biosorption capacity. Insights into biosorption mechanisms have been provided by various researchers in order to develop a fundamental scientific understanding of the biosorption process. However, biosorption has not been employed widely for its large-scale commercial applications. The key factors that affect the growth and evolution of biosorption as a practical technology for decontamination of wastewaters include, (1) lack of investigations on multi-component solutions and wastewaters with complex matrix effects, (2) incomplete understanding of physico-chemical characteristics of biomasses of different types, (3) lack of studies to improve the performance of biosorbents through surface functionalization, and (4) non-integration of biosorption in wastewater/water treatment plants. This critical review aims to identify and discuss the practical limitations of biosorption and provide future research directions to make biosorption a technologically viable process with emphasis on selection and modification of biomasses to suit desired treatment applications, identify appropriate operation modes for large-scale applications of biosorption, and perform techno-economic evaluation of overall biosorption processes. © 2015 Elsevier Ltd.

Journal of Environmental Management

Is biosorption suitable for decontamination of metal-bearing wastewaters? A critical review on the state-of-the-art of biosorption processes and future directions

Sorption capacity of oyster mushroom (Pleurotus platypus), button mushroom (Agaricus bisporus) and milky mushroom (Calocybe indica) were evaluated on biosorption of heavy metals, viz. cadmium (II) and lead (II) from aqueous solutions. The optimum sorption conditions were studied for each metal separately. The desired pH of the aqueous solution was found to be 6.0 for the removal of cadmium (II) and 5.0 for removal of lead (II) for all the mushrooms. The percent removal of both the metals was found to increase with the increase in biosorbent dosage and contact time. The fitness of the biosorption data for Langmuir and Freundlich adsorption models was investigated. It was found that biosorption of cadmium (II) and lead (II) ions onto the biomass of the three mushrooms were better suitable to Langmuir than Freundlich adsorption model. P. platypus showed the highest metal uptake potential for cadmium (qmax 34.96 mg/g) whereas A. bisporus exhibited maximum potential for lead (qmax 33.78 mg/g). Milky mushroom showed the lowest metal uptake capacity for both the metals. The present data confirms that mushrooms may be used as efficient biosorbent for the removal of cadmium (II) and lead (II) ions from aqueous solution. © 2009 Elsevier B.V. All rights reserved.

Journal	Data powered by TypesetDesalination
Publisher	Data powered by TypesetElsevier BV
ISSN	0011-9164
Open Access	0