Phytoremediation of xenobiotics – A green approach for the treatment of domestic wastewater

Abstract

Remediation of xenobiotics from wastewater is highly essential due to its harmful impacts. Several chemical and physical processes are used to recover xenobiotics from wastewater, including ion exchange, reverse osmosis, electrodialysis, and ultrafiltration. However, the biological method of employing microalgae, has aroused the scientific community’s interest due to its cheap operating costs and effectiveness in absorbing and/or removing organic and elemental contaminants from wastewater. Chlorella vulgaris was used as a biological absorbent, in the remediation of domestic wastewater (DWW). The results of this work indicated that C. vulgaris, effectively eliminated pollutants and improved the physicochemical characteristics of wastewater such as pH, DO, alkalinity. Simultaneously, it also decreased BOD, COD, suspended solids, heavy metals (HMs) such as iron (Fe), zinc (Zn), cadmium (Cd), mercury (Hg), copper (Cu), lead (Pb) and nutrient load (phosphate and nitrate) of DWW. Effective remediation of the pollutants was attained within 4h of C. vulgaris cultivation. The removal of toxic compounds such as 4-methoxy carbonyl benzo hydrazide, benzamine 4,4’ methylene bis, acetamide, and N-(2-methyl phenyl), was confirmed with GC-MS analysis. The removal of polysulfides and aliphatic bromo compounds was evident from the FTIR studies. Pearson’s correlation analysis showed a positive correlation between physicochemical variables and algal biomass. Hence, the current study recommends biological wastewater treatment,by utilizing C. vulgaris as an effective and eco-friendly option, for removing pollutants and restoring the physicochemical properties of water.