Method for treating urban sewage with low carbon nitrogen ratio by using sludge liquor as carbon source

Abstract

The invention provides a method for treating urban sewage with low carbon nitrogen ratio by using sludge liquor as a carbon source, which pertains to the technical field of water treatment in environmental engineering. The technical proposal of the invention is characterized in that higher-content organic matters in sludge liquor of excess sludge after thermal decomposition are used as an external carbon source; concentration of ammonian in the sludge liquor of excess sludge after thermal decomposition is lowered by an ammoniomagnesium phosphate settling method, thus raising the C / N ratio of the sludge liquor; and the sludge liquor is applied to sewage of lower total nitrogen deprivation rate due to shortage of carbon source by appropriate proportion, thus achieving the purpose of raising the total nitrogen deprivation rate. Compared with the prior art, the method has the advantages of saving cost on traditional carbon source, facilitating the operation, and having excellent environmental, economic and social benefits by a strategy of controlling waste by waste. Therefore, the method provides a final solution to thermal decomposition of the sludge liquor of excess sludge for sewage treatment plants.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering water treatment, and specifically relates to a method for improving the removal rate of total nitrogen by using the pyrolyzed residual sludge dehydration liquid of a sewage treatment plant as a carbon source in the treatment of sewage with relatively insufficient carbon sources. Background technique [0002] Due to the influence of region, climate and living habits, some cities in my country have a large per capita domestic water consumption, and these cities have more rainfall, resulting in higher groundwater levels, and mostly combined drainage systems and unreasonable septic tanks. Generally speaking, the domestic sewage in these cities has low organic matter concentration and not low nitrogen and phosphorus content. Generally, this kind of urban sewage with low organic matter content and relatively high nitrogen and phosphorus content is called low carbon and high nitrogen. Pho...

AI Technical Summary

Problems solved by technology

[0012] If urban domestic sewage has a relatively sufficient carbon source, the denitrification rate of sewage will be higher, but in fact, the carbon source material in urban domestic sewage is limited. For cities with low or even ultra-low concentrations of low carbon and high nitrogen and phosphorus Sewage, under anoxic conditions, the bioavailable carbon source material is insufficient, it is difficult to achieve the expected denitrification rate, and it also reduces the operating efficiency of the sewage treatment process