MOVING BED TYPE CONTINUOUS SAND FILTERING METHOD AND SYSTEM THEREFOR

摘要

PROBLEM TO BE SOLVED: To effectively allow the treatment of backwashing wastewater to correspond to the concentration of a pollutant in raw water. SOLUTION: Backwashing wastewater discharged from a sand filtering apparatus is distributed by a moving bed type continuous sand filtering system having a solid removing device in its pretreatment stage and a part thereof is guided to the solid removing device and treated along with raw water to be allowed to meet with the remaining backwashing wastewater and this combined water is sent in a filter apparatus as filter supply water and the distribution amount of backwashing wastewater is controlled on the basis of the concentration of a solid in the filter supply water. Only a necessary amount of backwashing water is circulated to a solid treatment apparatus in the high- degree cleaning of sewage wastewater or domestic wastewater wherein biological treatment method and a flocculation and sedimentation treatment method is used jointly to perform rational and efficient operation to reduce treatment cost.