Phytoremediation capability of Anabaena sp. for high organic and chromium-loaded wastewater in membrane bioreactors

Abstract

The efficiency of Anabaena sp. was analyzed for the phytoremediation of wastewater loaded with organic matter and heavy metals like chromium. Simulated wastewater was contaminated with chromium. A side-stream membrane bioreactor was used for the treatment of wastewater. A feed tank of 20 L capacity was used with a stirring arrangement. A ceramic microfiltration membrane composed of clay and alumina was obtained from Johnson & Johnson. The removal efficiency of chemical oxygen demand, biochemical oxygen demand, and chromium was evaluated. The process was used for algae harvesting and wastewater treatment. About 92% of chemical oxygen demand (COD), 98% chromium, and oil and grease were completely removed. Membrane fouling was explained by the pore blocking and cake resistance model. Stress in algal cells was determined from the superoxide dismutase (SOD) and catalase (CAT) analysis. The lipid content of algal cells was measured. HIGHLIGHTS A side-stream ceramic membrane bioreactor was used for the treatment of wastewater containing toxic heavy metals.; Application of algae-based bioremediation of chromium (Anabaena sp.) was done.; Reduction of COD (92%), Cr(VI) (98%), and complete removal of turbidity and oil was obtained in the process.; Algal harvesting and wastewater treatment were achieved in the process.; The biodiesel and lipid content of algae growing in wastewater are compared.;

Keywords

• algae
• bioreactor
• ceramic membrane
• filtration model
• lipid
• biodiesel