Abstract

The present study investigated the removal of toxic pollutants and reduction of heavy metals from tannery wastewater using Chlorella vulgaris. The physiochemical parameters like pH, electrical conductivity (EC), biological oxygen demand (BOD), chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), chloride, total hardness (TH), bicarbonate, magnesium, ammoniacal nitrogen, phosphate and heavy metals (Cu, Cr, Zn, Ni and Fe) were analysed using standard methods. Functional group of toxic chemicals in tannery wastewater and C. vulgaris treated wastewater were analysed by Fourier transforms infrared spectroscopy (FT-IR) and gas chromatography – mass spectrometry (GC-MS). 20 to 60% of chemicals (bicarbonate, chloride, nitrogen, phosphate and magnesium) were reduced by the treatment using C. vulgaris within 28 days. FT-IR and GC-MS analysis reveals that the functional group of azo compounds was not in C. vulgaris treated wastewater. Thus, the results obtained conclude that C. vulgaris can be used as a suitable tool for the removal of toxic chemicals of tannery wastewater.

Key words: Chlorella vulgaris, toxic chemicals, tannery wastewater, physio-chemicals, Fourier Transforms Infrared Spectroscopy (FT-IR), Gas Chromatography – Mass Spectrometry (GC-MS).