Sewage treatment method

Abstract

The invention discloses a sewage treatment method. The method comprises the following steps: step 1, pretreating sewage by adopting an electrode; step 2, performing flocculation treatment in a flocculation tank by adopting ferrous sulfate as a flocculating agent; and step 3, treating by adopting a biochemical process. The method has the beneficial effects that the BDD electrode or the graphene electrode is used for pretreatment so that COD in the sewage is reduced, organic matters which are difficult to biodegrade are decomposed into small molecular organic matters, organic nitrogen is converted into inorganic nitrogen, and organic phosphorus is converted into inorganic phosphorus, the biodegradability of the sewage is greatly improved, the mineralization degree of pollutants in the sewageis improved, and subsequent flocculation treatment is facilitated; part of pollutants can be removed through flocculation treatment, the pollutants can react with residual active oxygen of electrooxidation, and the influence on the subsequent biochemical process is reduced. The sewage treatment method is easy to operate and can be used for effectively treating sewage.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a sewage treatment method. Background technique [0002] With the rapid development of economy and society and the gradual improvement of people's quality of life, the discharge of industrial wastewater and domestic wastewater is increasing day by day. Water pollution seriously endangers the health and life of people and animals, and seriously threatens human production, life and ecology. Balance, for sewage that is difficult to biodegrade, advanced oxidation is generally used as pretreatment. Advanced oxidation includes Fenton and ozone electrooxidation. The Fenton process needs to add a large amount of ferrous sulfate and hydrogen peroxide, and the process produces a large amount of solid waste. However, the oxidation ability of ozone is too weak, generally only 20mg / L of COD can be reduced, and the biodegradability of sewage is not greatly improved. Electrooxidatio...

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Problems solved by technology

The current density of the DSA electrode generally does not exceed 200A / square meter, and the current density of graphite or carbon steel generally does not exceed 100A / square meter. The active oxygen produced by these two systems after treating sewage is relatively low. Generally, the sewage is aerated and then enters the biochemical system. However, these two electrodes have two weaknesses. One is that the electrode life does not exceed 2 years, and the other is that the degradation depth of sewage does not exceed 50%, and the market acceptance is low. Therefore, the present invention provides a combination of BDD electrodes and graphene electrodes. method of sewage treatment

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