High-altitude municipal wastewater treatment method based on nitrogen and phosphorus capture and whole-course autotrophic nitrogen removal

Abstract

The Tibet region in China has the characteristics of high altitude, low air oxygen content, large day and night temperature difference and low night temperature, so that a traditional activated sludgeprocess adopted for domestic sewage treatment at present confronts with the problems of low aeration efficiency, high energy consumption, weak functional microorganism activity and the like when being applied to the Tibet region; meanwhile, the treatment of a large amount of residual sludge threatens the ecological environment of the Tibet region. According to the method, a chemical enhanced primary treatment (CEPT) process and an integrated partial nitrosation-anaerobic ammonia oxidation (CPNA) process are combined, so that the capture of carbon and phosphorus in the inlet water and the whole-course autotrophic nitrogen removal under a low-oxygen condition are realized. The captured carbon source is used for producing biogas through anaerobic fermentation, and can supplement heat for a CPNA process under a low-temperature condition. The CEPT-CPNA process has the advantages of low energy consumption and less residual sludge generation, can solve many problems in the traditional method, and belongs to a sustainable sewage treatment process suitable for a high-altitude environment.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a high-altitude urban sewage treatment method based on nitrogen and phosphorus capture and whole-process autotrophic denitrification. Background technique [0002] The altitude in Tibet is high, the air oxygen content is low, and the temperature difference between day and night is large, and the temperature at night is low. Taking Lhasa as an example, the annual average air pressure, oxygen content and atmospheric density are respectively equivalent to 64%, 60% and 66% of sea level. The annual average temperature is 3-17°C, and the average nighttime temperature is only 3°C. In Tibet, under the same aeration conditions, the actual DO content in water is only about 50% of that in plain areas. Insufficient oxygen supply will affect the growth and metabolism of aerobic organisms, leading to major pollution of carbon, nitrogen, and phosphorus in sewage cannot be effectively ...

AI Technical Summary

Problems solved by technology

However, the traditional CEPT process mainly focuses on the removal of turbidity. Although it can also remove carbon sources (COD) and phosphorus, the removal rate is not high. Among them, the removal rate of carbon sources is less than 70%, and the residual COD is more

Moreover, the traditional CEPT process does not pay attention to the retention of ammonia nitrogen, so it cannot be used as a pretreatment for CPNA

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