Pesticide wastewater treatment technology

Abstract

The invention relates to a pesticide wastewater treatment technology. The pesticide wastewater treatment technology comprises the following steps: collecting and treating pesticide wastewater to be treated by class, remixing, diluting the pesticide wastewater till the COD content is 1800-2200mg / L and the NH3-N content is 150-250mg / L by using surface water and domestic food processing wastewater, and adjusting the pH of the diluted wastewater to 7.5-8.5; treating the diluted pesticide wastewater by an A / O technology, enabling the pesticide wastewater treated in the previous step to enter an ozone tower for advanced oxidation, and oxidizing phosphorus in the water into phosphate (PO4<3->); enabling the pesticide wastewater treated in the previous step to enter a moving bed biofilm reactor, enabling the oxidized wastewater to enter a coagulation tank, adding CaO into the coagulation tank, adding polyacrylamide after completion of a reaction, and completing precipitation to obtain effluentwater, namely the successfully treated pesticide wastewater. The pesticide wastewater treatment technology has the advantages of simple operation, a good phosphorus removing effect, a stable effect,and no secondary pollution caused by re-release of the phosphorus.

Description

technical field [0001] The invention belongs to the field of pesticide wastewater treatment, and in particular relates to a pesticide wastewater treatment process. Background technique [0002] Pesticide wastewater is mainly drainage during the production process, product washing water, equipment and workshop floor cleaning water, etc. The main components include benzene series organic matter, phenolic substances, high-concentration salt and organic phosphorus, etc. The main characteristics are: [0003] 1. High concentration of organic matter: The COD of comprehensive pesticide wastewater entering the sewage treatment station is usually between several thousand mg / L and tens of thousands of mg / L, while the COD of synthetic wastewater in the process of pesticide production can be as high as tens of thousands mg / L, sometimes even Up to tens of thousands mg / L. [0004] 2. The composition of pollutants is very complex: the production of pesticides involves many organic chemica...

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Problems solved by technology

[0003] 1. High concentration of organic matter: The COD of comprehensive pesticide wastewater entering the sewage treatment station is usually between several thousand mg / L and tens of thousands of mg / L, while the COD of synthetic wastewater in the process of pesticide production can be as high as tens of thousands mg / L, sometimes even Up to tens of thousands mg / L

[0004] 2. The composition of pollutants is very complex: the production of pesticides involves many organic chemical reactions, and many wastewaters contain not only raw material components, but also many by-products and intermediate products

[0005] 3. High toxicity and difficult biodegradation: In addition to pesticides, intermediates and by-products, there are also a large number of refractory compounds and some highly toxic substances in pesticide wastewater, such as benzene rings, phenols, arsenic, mercury and other toxic substances. It has an inhibitory effect on biodegradation; the wastewater generated during the synthesis of malathion pesticide contains difficult-to-degrade phosphorodithioate compounds

[0006] 4. Smelly and irritating odor: Pesticide wastewater usually has a foul or irritating odor, which has a certain stimulating effect on the human respiratory tract and mucous membranes. In severe cases, it may produce poisoning symptoms and endanger health.

[0007] 5. Unstable water quality and water quantity: Due to the requirements of enterprise operation and management, intermittent operation is required, so that the water quality and water quantity of pesticide production wastewater cannot be in a relatively constant state

For some industrial wastewater before entering the centralized or decentralized sewage treatment plant, in addition to the above-mentioned general pretreatment, water quality and quantity adjustment treatment and other special pretreatments are required, such as neutralization, hair removal, pretreatment, etc. Shen, pre-aeration, etc., if the pretreatment process is not up to standard, it will cause a lot of loss to the subsequent treatment equipment

The anaerobic aerobic process (AO process) is used to remove organic matter in water. A (Anacrobic) is an anaerobic stage, which is used for nitrogen and phosphorus removal; O (Oxic) is an aerobic stage. To improve the nitrogen removal efficiency, It is necessary to increase the internal circulation ratio, thus increasing the operating cost

In addition, the internal circulation fluid comes from the aeration tank, which contains a certain amount of DO, which makes it difficult to maintain the ideal anoxic state in the A section, which affects the denitrification effect, and the denitrification rate is difficult to reach 90%.

[0012] Due to the different types and quantities of pesticides produced, the water quality of pesticide wastewater produced every day fluctuates greatly, which makes the water quality of wastewater entering the biochemical treatment stage also fluctuate, causing a greater impact on activated sludge, affecting the activity of sludge, and reducing Treatment effect on wastewater

The methods in the prior art cannot achieve satisfactory results in the actual operation of the project, and the operating costs are high and the investment is large

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