Bioremediation of coke plant wastewater from steel industry with mixed activated sludge–microalgal consortium in lab‐scale semi‐continuous mode

Abstract

BACKGROUND: Removal of toxicities from wastewater has always demanded great attention as it has life-threatening impacts on every living being and the environment. In the present study, bioremediation of ammonia and cyanide from coke plant wastewater (CPWW) by using bacterial consortia with activated sludge (AS) supplemented with microalgal (MA) biomass in semi-continuous mode was performed. Parameters such as pH, total dissolved solids (TDS), dissolved oxygen (DO) and bacterial cell viability, along with any significant effect on the growth of microalgal cells in wastewater, was investigated by determining its specific growth rate (⊘).RESULTS: With pH values remaining constant for the system, the ammonia removal rate with microalgae additions was approximately 38.3% lower than that with AS. Similarly, the cyanide removal rate after addition of microalgae to the system showed a difference of 43% with AS treatment. TDS levels dropped by 22.18% and the concentration of DO increased by 21.91% in comparison to the values obtained by treatment of CPWW with AS and MA to CPWW with AS alone. CONCLUSION: Microalgae additions effectively increase the efficiency of AS treatment of CPWW and thus can be taken to field trials for developing a cost-effective and environmentally friendly strategy of wastewater treatment.