Use of the microalgae Chlorella Sorokiniana for municipal wastewater treatment: batch experiments

Batch experiments were conducted in order to investigate the use of microalgae Chlorella sorokiniana for the treatment of different types of municipal wastewater (raw sewage, anaerobically treated wastewater, aerobically treated wastewater) and investigate the role of light and addition of ammonium on its growth. All experiments were conducted in triplicates and lasted for 7 days. Several parameters were monitored during the experiments in order to check the experimental conditions (pH, temperature, DO), the growth of biomass and the removal of major pollutants (COD, NH4-N, PO4-P, NO3-N) from wastewater. According to the results, the target microalgae can be sufficiently developed in raw and anaerobically treated sewage, while it can remove an important part of the major pollutants found in raw sewage, reaching up to 94%, for COD, 99% for PO4-P and 94% for NO3-N. The addition of NH4-N in aerobically treated does not enhance growth of biomass, while the application of mixotrophic conditions (16h light/8h dark) enhanced microalgae growth and major pollutants’ removal.