WASTEWATER TREATMENT SYSTEM AND METHOD FOR COMBINED OZONE AND BIOLOGICAL FILTERS

摘要

Disclosed is a wastewater treatment system and method for an advanced treatment of refractory organic matters in wastewater. The wastewater treatment system comprises an ozone treatment device (1) and a biological filter (2). An ozone dosing device (3) of the ozone treatment device (1) prepares ozone by electric discharge using air or pure oxygen as a raw material. A mixed gas including ozone and excess air or oxygen discharged therefrom is introduced into an ozone-oxygen contact tank (7) such that the wastewater to be treated is subjected to ozone oxidation treatment and oxygen absorption, and an effluent is introduced into the biological filter (2), so that the biological filter (2) does not need to provide an aeration device to increase oxygenation for microorganisms. The wastewater treatment system and method fully utilize the supersaturated dissolved oxygen in the effluent of the ozone treatment device (1) to replace the aeration system of the subsequent biological filter (2), and have the advantages of high mass transfer efficiency, high biological activity, high volume load, high removal rate, and the like. The filter (2) has a simple structure and high backwashing efficiency, which significantly reduces operating costs. For the removal of refractory COD, the economics of the overall process are greatly improved.