TREATMENT OF STOCKBREEDING WASTE WATER

PURPOSE:To satisfy waste water quality standard by markedly reducing COD and BOD by substantially removing suspended solids, by applying ultrafiltration treatment to waste water containing urine of a domestic animal and succeedingly performing reverse osmosis treatment thereto. CONSTITUTION:Waste water containing not only several 1,000ppm of COD and BOD but also a remarkable amount of an SS-component is supplied to an ultrafiltration apparatus from a waste water tank 1 while pressurized by a pump P1 and filtered to remove the SS-component and colloidal components. The filtrate is sent to an intermediate tank 3 and the greater part of the unfiltered liquid is returned to the waste water tank 1 and recirculated to be again filtered. The filtrate is sent to a reverse osmosis apparatus 4 from the intermediate tank 3 while pressurized by a pump P2 and the greater part of the dissolvable COD component is removed herein while treated water after the removal of the COD component is sent to a treated water tank 5 and again reutilized or discharged. Because the reverse osmosis conc. liquid is rich in nutritive substances, it is returned to a farmland or sent to other treatment facilities.