Nature Environment and Pollution Technology

Devlina Das ¹, R. Vimala ¹, Nilanjana Das ¹

Affiliations
1 Environmental Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore-632 014, T.N., IN

Abstract

This study described the removal of Ag(I) from wastewater using macrofungus Pleurotus platypus in a packed bed column. The effect of operating parameters such as bed height, flow rate and initial metal concentration were investigated on removal of Ag(I) under optimized condition. The breakthrough curve profile signified that the breakthrough time and exhaustion time increased with an increase in bed height and a decrease in flow rate and initial metal concentration. The data were supported by 3D mesh diagrams and perturbation plots obtained from 2D factorial design. The column data were analysed using four models viz., BDST model, Emperical model, Thomas model and Yan model. The BDST model was found to be the best to fit the breakthrough curves at experimental conditions. The column was regenerated using 0.01 M HCl solution and sorption-desorption studies were carried out for three cycles. The obtained results implied that P. platypus may serve as suitable adsorbent material for the removal of Ag(I) from wastewater.

Keywords

Ag(I), Biosorption, Pleurotus platypus, Electroplating Wastewate, Packed Bed Column.

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R. Vimala ¹, Nilanjana Das ¹

Affiliations
1 Environmental Biotechnology Division, School of Biotechnology Chemical and Biomedical Engineering, VIT University, Vellore-632 014, Tamil Nadu, IN

Abstract

Lead, like other heavy metals, is introduced into natural waters by industrial and domestic wastewater discharges causing environmental pollution. Conventional methods are extremely expensive or inefficient for removal of metals from wastewaters containing low concentration of dissolved metals. Biosorption is a process in which sorbents of biological sources are employed for binding heavy metals. It is a promising alternative to treat industrial effluents, mainly because of its low cost and high metal binding capacity. In the present work, lead (II) biosorption process by the fruiting bodies of a macrofungus (Agaricus bisporus) has been studied. The work considered the determination of lead-biomass equilibrium data in batch system. The studies were carried out in order to determine some operational parameters of lead sorption such as the effects of pH, initial metal ion concentration, biomass dosage and time required for the metal biosorbent equilibrium, contact period, etc. All the parameters showed important effect on biosorption rate and capacity.

Keywords

Biosorption, Lead, Macrofungus, Agaricus bisporus, Langmuir Isotherm, Freundlich , Isotherm.

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D. Charumathi ¹, R. Vimala ¹, Nilanjana Das ¹

Affiliations
1 School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore-632 014, Tamil Nadu, IN

Abstract

Studies have shown that fungal organisms possess the capacity of heavy metal removal. In the present investigation, a study in batch system was conducted using the macrofungus, Agaricus bisporus as biosorbent for evaluating its potentiality to adsorb lead (II) ions from aqueous solution. To improve the bioadsorption capacity, the biosorbent was pretreated with NaOH, Na₂CO₃ and NaHCO₃. Pretreatment with NaOH resulted in a significant improvement in bioadsorption capacity. The experimental equilibrium data were adjusted by adsorption isotherms from Langmuir and Freundlich models and their equilibrium parameters were determined. For the untreated biosobent, the Langmuir model supplied q_max = 28.8 mg/g and b = 0.02 L/mg and for the Freundlich model parameters are K_f= 1.7 and n =1.8. For the sodium hydroxide (NaOH) treated biomass, the parameters were q_max = 34.6 mg/g, b= 0.08 L/mg, K_f = 5.3 and n = 2.3. The best adjusted model to the experimental equilibrium data for both untreated and sodium hydroxide (NaOH) treated biosorbent was the Langmuir model.

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