Evaluation of Desmodesmus subspicatus for the treatment of wastewater.

Microalgae are diverse in nature, capable to survive under diverse environmental conditions, and a good method of choice for remediation of polluted waters. Desmodesmus is a recently updated genus having capacity to consume wastewater nutrients under heterotrophic growth conditions. The aim of this study is to investigate the potential of Desmodesmus subspicatus for the treatment of wastewater. The treatment of wastewater was carried out for the period of 20 days at ambient temperature under continuous (24 hr) illumination of 4750 lm by a LED source withaeration at rate of 3.5 L/min by air pump. Treated wastewater samples with microalgae were then analysed for pH, total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia as NH4+ phosphate and nitrate on every 5th day during experiment to monitor the remediation process. The results showed that D. subspicatus significantly lowered COD (84%) and BOD (76%) levels. The removal efficiency of ammonia was maximum (approximately 100%), nitrate (91%), and phosphate (71%) from wastewater was also prominently observable. The treatment effectively reduced (80%) TDS up to permissible limits. D. subspicatus can growin nutrient rich waters and has the potential of remediation under photoautotrophic conditions. [ABSTRACT FROM AUTHOR]