Wastewater Treatment Using Microalgae

Six different concentrations of Chlorella vulgaris microalgae culture are incorporated with raw wastewater to improve treatment efficiency in three phases. In phase one of study, 30% and 40% microalgae were incorporated with raw wastewater with 24 hrs retention period for 18 days in a batch mode and these conditions are made same for all phases. During phase two and phase three of study, 20%, 25% and 35%, 45% micro-algae concentrations used to treat raw wastewater respectively. Amongst all the six concentrations, 30% microalgae behaves most efficiently and is able to reduce 34 to 81% COD, 43 to 75% nitrate, and 36 to 99% of phosphorous. Overall ammonia nitrogen reduction varies from 80% to 99%. No attempt was made to control temperature or evaporation losses. These attempts can definitely increase the growth process of microalgae and increase the removal efficiency of nutrients in wastewater.