Batch activated sludge treatment method for wastewater containing nitrate groups

摘要

PURPOSE:To increase the efficiency of removal of nitrogen from waste water by pouring the waste water into a treating tank contg. sludge kept at a specified temp., aditating them for a specified time without aerating and then carrying out aeration until the COD and BOD of the waste water are reduced to prescribed values or below. CONSTITUTION:When waste water contg. nitric acid radicals is denitrified, it is poured into a treating tank contg. activated sludge kept at 20-30 deg.C and they are agitated for a time calculated by an equation, agitation time (hr)=NO3 concn. (ppm)/(400-650) at 20-30 deg.C without aerating. Aeration is then carried out until the COD and BOD of the waste water are reduced to prescribed values or below. Nitrogen in the waste water can efficiently and economically be removed.