Domestic wastewater treatment using Chlorella vulgaris in an airlift bioreactor

Abstract

A wastewater treatment system using Chlorella vulgaris was applied to treat domestic wastewater in an airlift bioreactor. Nutrients removal present in the wastewater were assessed: Nitrogen (N), Phosphorus (P), Chemical Oxygen Demand (COD). Due to the presence of these nutrients in many aquatic environments, can cause severe environmental problems, such as, reduction in oxygen levels, that can consequently kill fish and other oxygen-dependent fauna. The air lift reactor was operated in continuous mode. The air lift reactor was previously inoculated with C. vulgaris, and three different hydraulic retention times (HRT), were assessed: 24, 36 and 48 h. The results obtained were as following: 22.90%, 38.87% and 49.68% COD; 28.9%, 23.32%, 27.45% N and 44.24%, 48.89%, 54.22% P for 24, 36 and 48 h respectively.