Enhanced sewage biological nitrogen and phosphorus removal method bases on polyhydroxyalkanoate metabolism regulation

Abstract

An enhanced sewage biological nitrogen and phosphorus removal method based on polyhydroxyalkanoates metabolic regulation, the method comprising the following steps: 1) passing the sewage through a primary sedimentation tank (3) to obtain granular organic substance, and importing the obtained granular organic substance together with the surplus sludge discharged from a secondary sedimentation tank (5) into a sludge thickening tank (6) for thickening; 2) anaerobically fermenting the thickened organic waste obtained from step 1) in a polyhydroxyalkanoates precursor production reactor (9) to synthesize a polyhydroxyalkanoates precursor; 3) after removing nitrogen and phosphorus from the anaerobically fermented mixture in a sludge conditioning tank (10), pumping the liquid into a polyhydroxyalkanoates precursor storage tank (11); 4) pumping the polyhydroxyalkanoates precursor into the polyhydroxyalkanoates production reactor (9) to produce polyhydroxyalkanoates; 5) pumping the polyhydroxyalkanoates produced in step 4) into a sewage biological nitrogen and phosphorus removal reactor (4) for nitrogen and phosphorus removal. The method increases the nitrogen and phosphorus removal rate to around 80% and 95%, and enables the effluent discharged after sewage treatment to meet the first level standard A of the sewage discharge standards, and also has advantages of easy process control, less production of greenhouse gas and sludge, and low transformation process cost, and the like.

Description

technical field [0001] The invention belongs to the technical field of biological treatment of water, waste water or sewage, and relates to a method for enhancing phosphorus and nitrogen removal of urban sewage by regulating the metabolism of polyhydroxyalkanoate (PHA) by an in-situ carbon source. Background technique [0002] With the development of the economy and the improvement of living standards, the discharge of industrial and domestic sewage has increased year by year, and the problem of water pollution has become increasingly serious. A large amount of nutrients such as nitrogen and phosphorus flow into natural water bodies such as rivers and lakes, resulting in widespread eutrophication. The discharge of nitrogen and phosphorus in sewage is the main cause of water eutrophication. Activated sludge method has become a main method for removing nitrogen and phosphorus in sewage because of its advantages such as easy operation. However, on the one hand, this method wi...

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Problems solved by technology

However, on the one hand, this method will cause greenhouse gas emissions and a large amount of primary and secondary sedimentation sludge is difficult to deal with; on the other hand, urban sewage generally has the problem of low carbon source concentration, and the low carbon-nitrogen ratio of sewage is difficult. Meet the increasing requirements of phosphorus and nitrogen removal

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