ARSENIC REMOVAL METHOD BY UPWARD FLOW, CONTINUOUSLY FLOATING BED FILTRATION IN WATER PURIFYING TREATMENT

摘要

PURPOSE: To lessen the installation surface area and suppress the arsenic concentration to wastewater standard or lower by filtering water in a prior stage by an upward flow, continuously floating bed way filtering method by which arsenic concentration can be adjusted and further carrying out final treatment of water filtration in a post stage by a quick filtration or a slow filtration apparatus. ;CONSTITUTION: Raw water, e.g. underground water, etc., is sent to an upward flow, continuously floating bed-way filtration apparatus 2 by a raw water pump 1. At that time, an oxidizing agent and a flocculant are poured to the apparatus from an oxidizing agent tank 3 and a flocculant tank 4, respectively, and they are mixed with the raw water by a pipe mixer 7. In the filtration apparatus 2, while being drawn out, a part of a filter medium is cleaned by carrying out air lift by a driving water pump 8 and a compressor 9 simultaneously with filtration. The treated water which comes out of the filtration apparatus 2 is stored temporarily in a pump pit 10 and then supplied to a finishing filtration apparatus 12 and finally treated by a quick filtration method or a slow filtration method. The arsenic concentration of the objective raw water to be treated is set to be 0.1mg/l or lower and the cleaned water discharge ratio to the raw water is set to be 5-20%.;COPYRIGHT: (C)1995,JPO