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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Geetanjali Basak ¹, Nilanjana Das ¹

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

Abstract

In the present study, the dead biomass of the two yeast species viz., Candida rugosa and Cryptococcus laurentii were subjected to various chemical treatments to assess the effects of pretreatment on zinc(II) removal from aqueous solution. Yeast biomass was pretreated with anionic surfactants viz., sodium dodecyl sulphate (SDS), sodium dodecyl benzene sulphonate (SDBS) and dioctyl sulphosuccinate sodium (DSS), alkali (sodium hydroxide, sodium carbonate and sodium bicarbonate), acids (hydrochloric acid, sulphuric acid and acetic acid), and organic solvents viz., methanol, formaldehyde and gluteraldehyde. Pretreatment of dead yeast biomass with anionic surfactants was found to improve the zinc(II) removal remarkably compared to all other treatments. Acid treatments resulted in significant reduction in zinc(II) removal efficiency. The pattern of zinc(II) removal efficiency of both the yeast species was found to follow the order: SDS (3 mM) > SDBS (3 mM) > DSS (3mM) > Na₂CO₃ (9 mM) ≥ NaOH (9 mM) ≥ untreated biomass > C₂H₅O₈ (7 mM) ≥ NaHCO₃ (9 mM) > CH₃OH (7 mM) > HCHO (7 mM) > CH₃COOH (5 mM) > HCl (5mM) > H₂SO₄ (5 mM). Maximum zinc(II) removal was noted in case of SDS treated C. rugosa and C. laurentii which exhibited 84.7 % and 74.5 % zinc(II) removal compared to the removal efficiency of 65.4 % and 54.8 % obtained by untreated C. rugosa and C. laurentii.

Keywords

Zinc(II), Removal, Yeast Species, Dead Biomass, Pretreatment.

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V. Lakshmi ¹, Nilanjana Das ¹

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

Abstract

The aim of this work was to ascertain the efficacy of immobilised yeast for the remediation of caffeine in soil under laboratory condition. Biostimulation with inorganic nutrients and bioaugmentation with caffeine utilizing single and mixed yeast cultures viz., Mixed culture 1, Mixed culture 2, Mixed culture 3 and Mixed culture 4 were employed as remedial options for the removal of caffeine from contaminated soil. To promote caffeine removal, biowaste materials (wheat bran, sawdust, peanut hull powder) were used as biocarriers for immobilization of caffeine degrading yeast species following the method of physical adsorption. We constructed laboratory biopiles to compare the treatment bioaugmentation with bioaugmentation combined biostimulation using single and mixed cultures of immobilized yeast. Maximum removal of caffeine was found to be 98.3 % after 24 days in the biostimulated soil which was bioaugmented with sawdust immobilized yeast mixed culture No. 4 consisting of three yeast species viz., Trichosporon asahii, Candida tropicalis and Candida inconspicua. Dehydrogenase activity in the soil was remarkably enhanced to 639 μg TPF g^-1 soil and microbial numbers were also increased for the soil treated under the same conditions described above. Phytotoxicity assay confirmed the reduction of caffeine toxicity in the contaminated soil after treatment. Thus, sawdust immobilized mixed yeast culture No. 4 could serve as potential tool for the remediation of caffeine from contaminated soil.

Keywords

Caffeine Contaminated Soil, Immobilization, Biostimulation, Bioaugmentation, Yeast Species.

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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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V. Vinodhini ¹, Nilanjana Das ¹

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

Abstract

The present study has been undertaken to evaluate performance efficiency of the Common Effluent Treatment Plant (CETP) at Vaniyambadi, Vellore. Waste water samples were collected at four different stages of the treatment units and analysed for various physico-chemical parameters such as pH, temperature, turbidity, EC, TSS, TDS, BOD, COD and heavy metals. The values obtained for different parameters were compared with standard values given by National Environmental Quality Standards (NEQS) for waste water quality. The CETP has been working with the norms of NEQS and Tamil Nadu Pollution Control Board (TNPCB) and meeting the standard discharge limits.

Keywords

Common Effluent Treatment Plant, Tannery Waste, Biological Treatment, BOD, COD.

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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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