title: Self-sustainable Chlorella pyrenoidosa strain NCIM 2738 based photobioreactor for removal of Direct Red-31 dye along with other industrial pollutants to improve the water-quality.
abstract: The genotoxic and carcinogenic effects of diazo dyes from industrial effluents pose a serious environmental threat by contaminating aquatic ecosystem and consequently impact human health. The potential of a diazo dye resistant, self-sustainable photosynthetic green alga Chlorella pyrenoidosa NCIM 2738 provides a viable green technology for an efficient biodegradation of diazo dye Direct Red-31 (DR-31) and overall improvement of water quality. Herein, we for the first time report the degradation of DR-31 using C. pyrenoidosa. Batch experiments were performed to optimize the effect of initial pH, contact time and toxicity-range of DR-31 in order to achieve the optimal conditions for maximum decolourization in continuous cyclic photobioreactor. In batch culture, C. pyrenoidosa exhibited 96% decolourization with 40mgL(-1) dye at pH3. The equilibrium was attained within 30min and the maximum uptake of 30.53mgg(-1) algal biomass was observed during this period. This was found to be fitted well with Langmuir and Freundlich adsorption isotherm. The FT-IR spectra showed a change from -N=N- to N-H suggesting the possible involvement of the azoreductase enzyme. The application of C. pyrenoidosa not only degraded the DR-31 but also improved the quality of water by reducing COD (82.73%), BOD (56.44%), sulphate (54.54%), phosphate (19.88%), and TDS (84.18%) which was further enhanced in continuous cyclic bioreactor treatment. The results clearly showed that C. pyrenoidosa provides an efficient, self-sustainable green technology for decolourization of DR-31 and improved the water quality.
authors.affiliation: Amity Institute of Biotechnology, Amity University, Noida 201308, India.
authors.forename: Surbhi
authors.initials: S
authors.lastname: Sinha
authors.affiliation: Amity Institute of Biotechnology, Amity University, Noida 201308, India.
authors.forename: Rachana
authors.initials: R
authors.lastname: Singh
authors.affiliation: Amity Institute of Biotechnology, Amity University, Noida 201308, India. Electronic address: chaurasia@skku.edu.
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Chaurasia
authors.affiliation: Amity Institute of Biotechnology, Amity University, Noida 201308, India. Electronic address: snigam@amity.edu.
authors.forename: Subhasha
authors.initials: S
authors.lastname: Nigam
mesh_terms: D001391:Azo Compounds / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D002708:Chlorella / Q000254:growth & development / Q000378:metabolism*; D004396:Coloring Agents / Q000378:metabolism*; D007220:Industrial Waste; D008027:Light; D010710:Phosphates / Q000032:analysis; D058433:Photobioreactors; D013431:Sulfates / Q000032:analysis; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification; D060753:Water Quality
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; C501278:Direct Red 12B; D007220:Industrial Waste; D010710:Phosphates; D013431:Sulfates; D014874:Water Pollutants, Chemical
keywords: Biodegradation; Decolourization; Direct Red-31; Enzymatic Activity; Phycoremediation; Textile effluent