Method for performing nitrogen biological removal on low-temperature low-carbon nitrogen ratio sewage

Abstract

The invention relates to a method for performing nitrogen biological removal on low-temperature low-carbon nitrogen ratio sewage. A device with anoxia ponds and aerobic ponds which are distributed alternatively, arrayed continuously and are communicated with one another, sewage raw water respectively flows into each anoxia pond, outlet water of the tail end aerobic ponds respectively flows back to each anoxia ponds, and biological membrane modules are arranged in each aerobic pond to maintain biomass of activated sludge. Compared with the prior art, the nitration efficiency in the aerobic section is effectively improved by the method through optimizing the raw water to inlet water ratio and equinox backflow ratio in second-stage anoxia-aerobic process, the biomass of activated sludge is maintained by using the biological membrane modules, on one hand, the outlet water quality is improved under normal work conditions, and on the other hand, high-efficient nitration under low-temperature condition is realized. The COD value, the ammonia nitrogen content and total nitrogen level of the outlet water are lower in average, and the first level A standard can be reached under a low-temperature low- carbon nitrogen ratio condition.

Description

technical field [0001] The invention relates to a method for carrying out biological denitrification of sewage, in particular to a method for carrying out biological denitrification of low-temperature low-carbon-nitrogen ratio sewage. Background technique [0002] The sewage influent of urban sewage plants has the characteristics of low carbon-to-nitrogen ratio, and its carbon-to-nitrogen ratio (COD / TN) is generally much lower than the ideal biological denitrification requirement of 10:1. Constrained by insufficient organic carbon sources, and the nitrification reaction is inhibited under low temperature conditions in the north, the denitrification effect is further weakened, making it difficult for the total nitrogen in the effluent to reach the standard. At present, the mainstream activated sludge process in urban sewage plants is anoxic-aerobic process, which has the advantages of stable operation, simple operation and maintenance, and effective denitrification. [0003]...

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Problems solved by technology

[0003] In order to strengthen the biochemical efficiency of the anoxic-aerobic process under low temperature conditions, at present, people mainly focus on engineering measures to adjust the working parameters (sludge age and bioburden), that is, by maintaining high sludge age and low bioburden of activated sludge. , in order to achieve effective removal of refractory complex organic matter, but the characteristics of the sludge are guaranteed by the overall optimization of the environmental conditions. It is difficult to maintain the ideal sludge properties for a long time if the parameters of individual working conditions are changed. If the load is reduced alone, it is difficult to maintain The sludge has high activity and high sludge concentration, and the overall performance of the anoxic-aerobic system is difficult to maintain stability

In existing engineering applications, the mixing and shearing effect in the tank is also enhanced by strengthening the air aeration intensity of the aerobic tank (O tank), but this will inevitably cause waste of energy consumption for air aeration, and the effect obtained is not significant

[0004] Therefore, the current anoxic-aerobic process has low nitrification, denitrification and organic pollutant removal efficiency, so that the COD value, ammonia nitrogen content and total nitrogen level of the effluent are still high

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