Abstract
Microalgae cultivation systems are important for utilizing sewage resources or producing biomass in a wastewater treatment plant (WWTP). The aim of our study was to establish an naturally generating microalgae cultivation system that utilizes several sewage resources in a WWTP. To this end, we investigated the utilization of sewage sludge, which is a sewage resource, in relation to microalgae cultivation. Excess sludge was diluted with raw wastewater and was used as a substrate for microalgae cultivation.
Results showed that when substrate added dilutied sludge, microalgae biomass (SS and chlorophyll a) was increased, with a higher SS concentration. Furthermore, approximately 80% - 90% of COD (Chemical Oxygen Demand) in raw wastewater were removed because of the microalgae cultivation utilizing sewage sludge. In addition, additional amounts of CO2 for microalgae cultivation can be reduced by the presence of bacteria, and the total amount of heat value of cultured microalgae can be increased by the addition of sewage sludge.
In this study, it was shown that a microalgae cultivation system utilizing sewage sludge could produce more microalgae biomass and had a higher efficiency than that without using sewage sludge in WWTPs.
