Abstract
A test plant and a wastewater treatment system for a practical and biological treatment of lipid containing wastewater were installed at a Meat Plant in the Sendai district of Japan. In these systems, the raw wastewater was primarily treated in the cultivation tank where a lipid-assimilating bacterium was inoculated. The mixture of the wastewater, bacterial cells and air was taken at the surface of the tank and transported to the bottom of the tank. The wastewater was subsequently treated by activated sludge process as usual.
The test plant was very effective in removing lipid of the wastewater which contained relatively hibh concentration of lipid. When the whole contents of the cultivation tank were transferred to an aeration tank, the digestion of lipid, and the decreases in COD and BOD were further observed. A practical cultivation tank was installed at a prior step to the aeration tank which existed in the Meat Plant. COD and BOD of effluent were lower than 35 and 10mg·l-1, respectively. These values cleared the effluent standard.
From these results mentioned above, it was confirmed that lipid-containing wastewater could be treated by this system without using a physical treatment.
