Sewage treatment system and sewage treatment method

Abstract

The invention provides a sewage treatment technology and particularly relates to a technology for treating low-carbon / nitrogen-ratio sewage on the basis of dominant culture of high-concentration heterotrophic endogenous denitrifying bacteria and autotrophic nitrifying bacteria populations. Specially arranged sedimentation tanks are adopted to prevent dominant growth of heterotrophic microorganisms relative to autotrophic nitrifying bacteria after the heterotrophic microorganisms enter aerobic tanks, so that the autotrophic nitrifying bacteria keep high concentration and high activity, and high-efficiency ammonia-nitrogen nitrification is realized. With adoption of an alternate water inlet and outlet mode, the heterotrophic microorganisms in anaerobic tanks / anoxic tanks convert organic carbon sources into intracellular PHB (poly-beta-hydroxybutyrate) in a first half cycle, intracellular PHB is taken as an electron donor for denitrification in a second half cycle, the limited carbon sources in the sewage are used to the greatest extent for denitrification and are prevented from entering the aerobic tanks and being subjected to oxidation consumption, ammonia nitrogen in the low-carbon / nitrogen-ratio sewage is removed effectively under the condition that an external carbon source is not needed, synchronous nitrification and denitrification are realized, the dephosphorization effect is good, and the technology has good application prospect.

Description

technical field [0001] The invention relates to a treatment technology for sewage, in particular to a technology based on superior cultivation of high-concentration heterotrophic endogenous denitrifying bacteria and autotrophic nitrifying bacteria populations to treat sewage with a low carbon-to-nitrogen (C / N) ratio, which belongs to environmental protection Sewage treatment technology field. Background technique [0002] Water is the source of human life and the foundation of survival. With the development of industrial and agricultural production, water environment problems have become more and more serious, and water quality problems have seriously affected our normal life. Therefore, it is necessary to find effective sewage purification technology to realize the sustainable utilization of water resources. In recent years, people have established many mature and effective sewage treatment methods, such as the activated sludge process in sewage treatment plants in major ...

AI Technical Summary

Problems solved by technology

For example, in the traditional A / O method, organic matter and ammonia nitrogen are oxidized at the same time in the aerobic tank, which will lead to: 1. An increase in energy consumption for aeration of oxygen (need to supply oxygen for the oxidation of organic matter and ammonia nitrogen), 2. Heterotrophic aerobic Type bacteria and autotrophic aerobic bacteria (nitrifying bacteria) grow in the same reaction tank, and heterotrophic aerobic bacteria grow predominantly and gradually dominate the sludge, while the proportion of nitrifying bacteria in the sludge gradually decreases , the nitrification activity gradually weakens; 3. There is not enough organic carbon source for denitrification

Therefore, when treating sewage with a low carbon-to-nitrogen ratio, the denitrification reaction is often incomplete due to insufficient carbon sources.

In order to make the effluent water quality up to standard, it is necessary to add additional carbon sources such as ethanol, which greatly increases the treatment cost

Images