Biosorption of landfill leachate by Phanerochaete sp. ISTL01: isotherms, kinetics and toxicological assessment

ABSTRACT

The study investigates the ability of fungus Phanerochaete sp. ISTL01 for biosorption of color from landfill leachate. Batch mode experiments were conducted to study the effects of pH, temperature, adsorbent dose, contact time and initial leachate concentration on biosorption. Maximum biosorption capacity was determined as 17.73 mg g⁻¹ of biomass. Equilibrium isotherms and kinetics were further studied. The biosorption data were found to fit well to the Freundlich isotherm and pseudo-second-order kinetic model. The value of activation energy suggested that chemisorption mechanism was involved. Biosorption efficiency was also evaluated by the Methyltetrazolium (MTT) assay for cytotoxicity and alkaline comet assay in HepG2 human hepato-carcinoma cells. The fungus reduced toxicity as shown by 1.3-fold increase in MTT EC₅₀ and 1.5- and 1.1-fold reduction in Tail moment and Olive tail moment, respectively, after 12 h biosorption. The fungus showed good biosorption characteristics in terms of contaminant-level reduction per unit mass of adsorbent, process kinetics and toxicity reduction, envisaging its application in leachate treatment.

KEYWORDS:

• Landfill leachate
• biosorption
• fungi
• isotherm
• toxicity reduction

Acknowledgements

We would like to express our sincere thanks to Council of Scientific and Industrial Research, Government of India, New Delhi, for providing SRF (Ghosh, P). We also thank Dr J.K Tripathi (SES, JNU, New Delhi) for ICP-AES analysis, Dr Manoj Pratap Singh, Dr Ruchita Pal (Advanced Instrumentation Research Facility – AIRF, JNU, New Delhi) for FTIR and SEM-EDX analyses. We would also like to extend our sincere thanks to Dr Mihir Tanay Das, Ms Moni Kumari, Ms Swati and Mr Subhanjan Sengupta for their excellent technical assistance in preparing the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.