SEPARATION OF LIQUID AND SOLID BY FILTER MEDIUM

摘要

PURPOSE:To prevent deterioration of filtration capacity by using accessory material used for aerobic fermentation treatment as a filter medium and holding solid contained in sewage on the filter medium, and also performing work as the accessory material similarily to the case of aerobic fermentation treatment, decomposing and removing solid. CONSTITUTION:When sewage generated from a pig-pen is uniformly spread on the upper surface of a filter medium 1 such as sawdust built-up on a stainless steel network 8 and victoria lawn 7 in the lower part of a filter tank from a sewage spray pipe 3 by a pump, solid contained in sewage is almost filtered and held on the upper layer part of the filter medium 1. Filtrate is passed through a distributing water pipe 10 thereof and stored in a receiving tank 11 and separation of liquid and solid is performed. The solid held on the upper layer part of the filter medium 1 is agitated and mixed by actuation of an agitating and cutting device 2 and aerobic fermentation treatment is performed. In this case, when filtration capacity is deteriorated in a state wherein the present agitation depth is maintained, the agitation depth of an agitation shaft 5 is deepened by an elevating/lowering device 6 of the agitation shaft and the clogging part is agitated and mixed to perform aerobic fermentation treatment. Thereby deterioration of filtration capacity is prevented.