Accurate chemical dosing system and chemical dosing method for sewage treatment

Abstract

The invention discloses an accurate chemical dosing system and a chemical dosing method for sewage treatment. The system comprises a treatment tank group, a phosphorus removing agent feeding assembly,a carbon source feeding assembly, a disinfectant feeding assembly and a control assembly. The method comprises the following steps: adjusting the feeding of an aluminum salt phosphorus removing agent, a ferric salt phosphorus removing agent and a carbon source according to a monitoring value of water outlet total phosphorus; adjusting the feeding of the carbon source according to a monitoring value of water outlet total nitrogen; adjusting the feeding of a disinfectant according to a monitoring value of water outlet residual chlorine. The system disclosed by the invention has the advantage ofhigh automation degree, the chemical phosphorus removing agent can be fed according to water outlet on-line TP (Total Phosphorus), the water outlet stability is improved, and the problem of standardreaching lag of chemical dosing and water outlet quality is solved to a maximum extent, so that the system is more stable and safer; meanwhile, frequency of a chemical dosing pump can be adjusted according to a feeding ratio so as to control a chemical dosing amount, and therefore, a using amount of a medicament is reduced to a maximum extent, so that chemical dosing phosphorus removal, denitrification and sterilization are more scientific, and the sewage treatment cost is also reduced.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a precise dosing system and a dosing method for sewage treatment. Background technique [0002] Nitrogen and phosphorus nutrients are the main compounds that cause eutrophication of water bodies. With the increasing development and utilization of environmental resources by human beings, a large amount of domestic sewage and industrial wastewater containing nitrogen and phosphorus nutrients are discharged into rivers and lakes, increasing the load of nutrients in water bodies, and the direct consequence is eutrophication of water bodies. Phosphorus in sewage can be removed by chemical and biological methods. Biological phosphorus removal is a relatively economical phosphorus removal method, but since the current biological phosphorus removal process cannot guarantee that the total phosphorus in the effluent can reach the standard of 0.5mg / L, it is often necessary to use ...

AI Technical Summary

Problems solved by technology

Due to manual adjustment, it is difficult to accurately control the dosage of sodium hypochlorite, often resulting in insufficient dosage of chemicals to affect the quality of effluent water, or excessive dosage of chemicals, and excessive dosage of sodium hypochlorite will cause residual chlorine in the effluent High, affecting the discharge water environment

Sodium hypochlorite dosing in some sewage treatment plants with a relatively high degree of automation adopts the precise dosing mode, that is, the instantaneous water inflow is collected through the computer control system, and the flow rate of the sodium hypochlorite dosing pump is automatically adjusted according to the set dosing ratio. The water quality changes greatly. It is not scientific to determine the dosage of sodium hypochlorite according to the fixed dosage ratio, which may easily cause problems such as high residual chlorine content in the effluent, affecting the environment of the discharged water body, or poor disinfection effect.

Both of the above two dosing methods need to use the test data to feedback whether the dosage of sodium hypochlorite meets the disinfection effect, and when each test takes 48 hours, the feedback has a lag and affects the quality of the effluent water

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