Efficient denitrification method by use of upgraded and modified ICEAS process for urban sewage treatment plant

Abstract

The invention provides an efficient denitrification method by use of an upgraded and modified ICEAS (Intermittent Cyclic Extended Aeration System) process for an urban sewage treatment plant and belongs to the technical field of sewage treatment. The method enables the removal rate of total nitrogen in effluent to be increased by at least 5% based on the original while keeping the removal rate of COD (Chemical Oxygen Demand) and ammonia nitrogen in the effluent basically unchanged, without adding an external carbon source. Relatively low carbon-nitrogen ratio of raw water is a problem that urban sewage plants in China face together; insufficient carbon source at the denitrification stage is a major factor of limiting the total nitrogen removal rate of the urban sewage treatment plants to be low, but external addition of the carbon source to increase the carbon-nitrogen ratio or new addition of a structure to increase the hydraulic retention time of sewage certainly leads to the increase of sewage treatment cost. The efficient denitrification method is characterized in that continuous water feeding is changed into intermittent water feeding, the carbon source in the raw water is utilized efficiently for denitrification instead of only adopting aerobic aeration oxidation, and the operating mode of the system is optimized, and a return pipe from a main reaction region to a pre-reaction region is newly added to comprehensively increase the removal rate of total nitrogen in the effluent. The efficient denitrification method has reference guidance significance for the upgrading and modification of the sewage treatment plants of similar processes.

Description

technical field [0001] The invention relates to an upgrading method for high-efficiency denitrification of urban sewage treatment plants with low carbon-to-nitrogen ratio ICEAS technology, and belongs to the field of sewage biological treatment. Background technique [0002] my country's sewage treatment industry has achieved rapid development since the reform and opening up in 1978, which has greatly improved the level of urban sewage treatment. 98.8% of the total number of cities; a total of 3,451 urban sewage treatment plants have been built in cities and counties across the country, which has greatly improved my country's sewage treatment capacity. [0003] At present, the tail water discharge standards of most sewage treatment plants in my country are implemented or after transformation, the first-level A discharge standards in the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002) are implemented, which stipulates that the total nitrogen co...

AI Technical Summary

Problems solved by technology

Compared with traditional biological denitrification methods, these new technologies for nitrogen removal can significantly improve the total nitrogen removal rate. However, most of t

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