Abstract
The value of Chemical Oxygen Demand for the wastewater discharged from the purification process of BDF production was very high (ca.50,000 ppm) because the wastewater contained BDF. So it is not permitted to discharge the wastewater out. We have had a good result by that the wastewater was treated by a activated sladge after removing BDF from the wastewater. But it is important for cost down of BDF production to minimize the volume of the wastewater. In this study, the volume of water added to the purfication process and times of washing operation are discussed.
Four times washing carried under the rate of volume of water added to crude BDF(BDF:water = 10:2) was recomeded. And using absorbance or erectrical conductivity was also recomended as an indicator for degree of refining.
