The mechanism of Cd(II) uptake by the dead biomass of macrofungus Pleurotus platypus was investigated using different chemical and instrumental techniques. Sequential removal of cell wall components of the biosorbent revealed that structural polysaccharides play a predominant role in the biosorption of Cd(II). The adsorption kinetics fitted well with the pseudo second-order model suggested that the adsorption of Cd(II) on P. platypus involved a chemisorption process. Transmission electron microscopy of the cadmium exposed biomass confirmed the deposition of the metal mainly in the cell wall. Fourier transform infrared spectroscopic analysis of the metal loaded biosorbent confirmed the participation of -OH, -NH and C-O-C groups in the uptake of Cd(II). Energy dispersive X-ray analysis of the biosorbent before and after metal uptake revealed that the main mechanism of adsorption was ion-exchange. The effectiveness of CaCl2 in the desorption of cadmium perhaps suggested the exchange of Ca2+ with Cd(II). © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Vimala R

Department of Bio-Medical Sciences

School of Bio Sciences and Technology

Vellore Campus

Nilanjana Mitra

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.

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VIT University

Mechanism of Cd(II) adsorption by macrofungus Pleurotus platypus

Journal of Environmental Sciences

Electricals and electronic equipments that have reached its utilization period are disposed by the consumer are considered as e-waste. The categories of e-waste range from household appliances to machines used in offices and consumer goods. The rise in problem is due to scarcity of proper place for disposing the e-wastes. Hence, the wastes are disposed in open landfills by the consumers which lead to direct reaction of the e-waste with the environment. The release of harmful toxins and chemicals by the e-wastes causes hazardous effects on living beings. Several processes are introduced in recycling and recovering the harmful metals present in the electronic equipments. The most important reasons for e-waste recycling are waste removal as well as recovery of valuable materials present in the waste. Developed countries such as USA and UK follow some strict rules and regulations about managing the increasing amount of e-wastes, whereas India still needs to have a rigid law for the e-waste management. Prior recycling and recovering the important metals from electronic wastes, it is crucial to ascertain the amount of the metal present in the e-waste. Plastics followed by metals are the main components found in electronic wastes. Hazardous metals such as copper, lead and cadmium are predominant in almost all kinds of e-wastes. Determination of the components present in the electronic wastes guides for the proper path to be followed for recovering the components from the wastes. The review deals with status of e-waste across the world and methods of recovery and management. © 2016, Islamic Azad University (IAU).

International Journal of Environmental Science and Technology

Efficient management of e-wastes

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.

Ecological Engineering

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

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 of Hazardous Materials

Biosorption of cadmium (II) and lead (II) from aqueous solutions using mushrooms: A comparative study

Biosorption of As(III) and As(V) from aqueous solution by macrofungus (Inonotus hispidus) biomass: Equilibrium and kinetic studies

Bioresource Technology

Cadmium removal from simulated wastewater to biomass byproduct of Lentinus edodes

Colloids and Surfaces A: Physicochemical and Engineering Aspects

Biosorption of chromium from aqueous solutions by pretreated Aspergillus niger: Batch and column studies

Environmental Pollution

The marine macroalga Cystoseira baccata as biosorbent for cadmium(II) and lead(II) removal: Kinetic and equilibrium studies

Journal	Data powered by TypesetJournal of Environmental Sciences
Publisher	Data powered by TypesetElsevier BV
ISSN	1001-0742
Open Access	0