Short-range nitrification-denitrification dephosphorization and denitrogenation method for reinforced low-carbon/phosphorus-ratio sewage

Abstract

The invention relates to a short-range nitrification-denitrification dephosphorization and denitrogenation method for reinforced low-carbon / phosphorus-ratio sewage, belonging to a wastewater treatment method. The method comprises the following steps: adding sewage to be treated into a reactor, and carrying out anaerobic phosphorus-release and carbon source absorption reaction with microbes which are grown on the bottom in a suspended mode; after the anaerobic phosphorus-release finishes, refluxing the upper mixed solution to a lower suspension growth region, and elevating the ammonia-nitrogen-enriched mixed solution subjected to anaerobic phosphorus-release to an upper attached growth region; aerating the microbes in the attached growth region to enable short-range nitrification of aerobic nitrobacteria; after the aerobic nitrification finishes, circulating the upper nitrification solution to a lower suspension sludge region to carry out anoxic denitrification phosphorus-adsorption reaction; and after the anoxic denitrification phosphorus-adsorption reaction finishes, discharging a certain amount of phosphorus-enriched sludge by an emptying valve / sludge valve. The invention solves the contradiction between the competition of nitrite bacteria and polyphosphate accumulating bacteria for the sludge age and the competition of polyphosphate accumulating bacteria and denitrifying bacteria for the carbon source, has stable and efficient short-range nitrification-denitrification dephosphorization efficacy, saves the aeration and carbon source, and is suitable for denitrogenation and dephosphorization treatment of low-C / P-ratio sewage.

Description

technical field

[0001] The invention relates to a waste water treatment method, in particular to a short-range nitrification and denitrification method for strengthening low-carbon-phosphorus-ratio sewage to remove phosphorus and nitrogen. Background technique

[0002] Eutrophication of water body is a global environmental problem, which is caused by overgrowth of algae caused by excessive nitrogen and phosphorus content in water body. In order to further reduce the harm caused by nitrogen and phosphorus to the water environment, many countries and regions have enacted new discharge standards for nitrogen, phosphorus and other indicators in sewage. For example, the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002) promulgated by our country clearly stipulates stricter TP, NH 3 -The emission standards of N and TN are respectively: TP≤0.5mg / L, NH 3 -N≤5mg / L, TN≤15mg / L (Class A standard). At present, most of the secondary sewage treatment plant...

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