BATCH TYPE ACTIVATED SLUDGE PROCESS FOR POLLUTED WATER

摘要

PURPOSE: To process the waste water containing ammonia nitrogen and phosphoric acid phosphorus in a short time by a batch type activated sludge treatment even if a lowest treatment water temperature is equal to a specific low temperature. CONSTITUTION: A nitration process for ammonia nitrogen, a denitrification process for nitrous acid nitrogen and/or nitric acid nitrogen, a process for taking phosphoric acid phosphorus into activated sludge, and a process for separating activated sludge and treated water are performed in one bioreactor. When a lowest processing temperature of polluted water is 5-10 deg.C, (time for nitration process)/(time for denitrification process) is made 2-3 to make the time for nitration precess longer than the time for denitrification process. Immediately before the separation process, a flocculant is added directly to the bioreactor to remove phosphoric acid phosphorus, and it is preferable that iron chloride (II), as the flocculant, is added to the polluted water under conditions that the mole ratio of the iron chloride to the phosphorus contained in the waste water Fe/P is 0.5-3.