Urban domestic sewage treatment process and its method

Abstract

The city sewage treatment process includes the following steps: utilizing grile and desilting basin to pretreat sewage, adding coagulating agent to make the phosphorus, heavy metal and orgnaic matters existed as colloid and suspended substances feed into anaerobic reactor in the form of sludge to make organic matter convert into impure methane, making the supernatant fluid pass through the next aerobic treatment reactor to remove organic matter and convert the ammoniacal nitrogen into nitric nitrogen, mixing anaerobic discharged water and aerobic discharged water, and making the mixture waterundergo the process of anaerobic treatment to make denitrifcation, finally utilizing secondary aeration and precipitation to completely remove organic matters from sewage so as to attain the goal of cleaning the sewage.

Description

technical field [0001] The invention relates to a process and a method for domestic sewage treatment, and belongs to the technical field of environmental protection and rational utilization of water resources. Background technique [0002] Water pollution and water shortage are one of the serious environmental problems facing our country. According to statistics, since 1985, my country's annual sewage discharge has been maintained at 35 billion to 40 billion m 3 about. my country's urban sewage treatment rate was only 3.3% in 1991, and a large amount of sewage was directly discharged, causing 82% of the country's 532 rivers to be polluted to varying degrees. The direct discharge of a large amount of sewage not only destroys ecology and aggravates water shortages, but also seriously endangers industrial and agricultural production and human health and safety. In order to control water pollution and protect water resources, the state has launched the "Three Rivers and Three...

AI Technical Summary

Problems solved by technology

The main problems are: 1. High power consumption and large footprint

For soluble and rapidly degradable COD, this part is easy to remove; but for COD caused by insoluble and poorly soluble substances, it is very difficult to remove

In order to remove this part of the substance, it is necessary to aerate for a long time, which leads to the extension of the overall aeration time, which results in an increase in the area of ​​the treatment facility, infrastructure investment and operating costs.

Substances must be aerated for a long time, which leads to the extension of the overall aeration time, which results in an increase in the area of ​​the treatment facility, infrastructure investment and operating costs

2. Cannot effectively remove nitrogen and phosphorus in sewage

This will inevitably increase the floor area, power consumption and operating costs

[0010] In order to achieve the phosphorus removal effect, the A-O (anaerobic-aerobic) process is currently used, but due to the limitation of the biomass of the activated sludge method (SS is about 1500~3000mg / l) and the limitation of the phosphorus accumulation characteristics of the phosphorus accumulating bacteria itself, the The phosphorus content in water is generally higher than several mg / l, which makes it difficult to meet the new sewage discharge standards

[0011] In order to simplify the process, the A-A-O (anaerobic-anoxic-aerobic) process for synchronous removal of nitrogen and phosphorus is currently used (the purpose of anaerobic here is only to release phosphorus), but this process also has long aeration time and power The problems of large consumption, large floor area, low removal rate of phosphorus and secondary pollution of phosphorus

3. It is difficult to effectively remove heavy metals, chroma and some refractory organic substances

4. The amount of sludge produced is large, the content of organic matter is high, and the sludge treatment is difficult and costly

Although the sewage in some places has been effectively treated, the sludge has not been properly treated and disposed of, causing secondary pollution

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