Treatment method for paraquat pesticide wastewater

Abstract

The invention discloses a treatment method for paraquat pesticide wastewater, and belongs to the technical field of treatment of the three wastes. The treatment method comprises the following steps: carrying out ozone oxidization, concentration and crystallization, and salt-leaching, introducing ozone for 1-2 hours after adding an adsorbent to completely oxidize cyanides; adding hydrogen peroxide to promote ozone oxidization speed, adding less hydrogen peroxide and then keeping the color of the mixture stable after the oxidization is ended, filtering to remove waste residues, and directly concentrating the obtained wastewater, rinsing the obtained salt with less washing water to reach industrial salt standards. The treatment method is applied to treating the paraquat pesticide wastewater, is relatively low in treatment cost, low in equipment requirement, low in operation cost, great in value of recycled salts and suitable for wastewater treatment of small and medium-sized enterprises.

Description

technical field [0001] The invention relates to a treatment method for paraquat pesticide wastewater, belonging to the technical field of three wastes treatment. Background technique [0002] With the rapid development of agriculture, the types and amounts of pesticides are also increasing rapidly. At this stage, most of the pesticides used in my country are organic pesticides, many of which are highly toxic and difficult to decompose. Pesticide wastewater has become a major problem in the field of water treatment. . Currently commonly used methods are: biochemical treatment, incineration, super oxidation, etc.: biochemical treatment generally requires long-term domestication of microorganisms, and the effect is unstable. Many pesticides cannot be completely decomposed, and some microorganisms will convert them into more difficult and more toxic pesticides. products; the incineration method requires harsh conditions, the cost is too high, and it is easy to leak toxic and har...

AI Technical Summary

Problems solved by technology

Currently commonly used methods are: biochemical treatment, incineration, super oxidation, etc.: biochemical treatment generally requires long-term domestication of microorganisms, and the effect is unstable. Many pesticides cannot be completely decomposed, and some microorganisms will convert them into more difficult and more toxic pesticides. The product of the incineration method is harsh, the cost is too high, and it is easy to leak toxic and harmful gases; super oxidation requires high equipment, so the cost is high, and the operation risk is relatively high, so it is difficult to popularize

[0003] Some enterprises use activated sludge method combined with incineration method to treat paraquat wastewater (Zhang Yongmei, etc.), and the estimated cost is about 2,000 yuan / ton of wastewater; some enterprises use catalytic oxidation method (CN 1576242A), adding catalyst to wastewater, at 100-200 ℃, 0.9-1.5MPa under the conditions of reaction for 12-24 hours, the removal rate of COD is higher than 90%, the removal rate of cyanide is almost completely removed, and the removal rate of chroma is also more than 90%. The effluent can directly enter the biochemical pool, but this process The required pressure is relatively large, the reaction time is long, and the cost is too high. It is not suitable for continuous industrial wastewater treatment systems for small and medium-sized enterprises and large enterprises; process, recovery of paraquat by extraction method, absorption of cyanide with alkaline emulsion, and second-effect evaporation of waste water after cyanide removal to obtain ammonium salt. This process recovers most of the harmful substances, but the recovery process is complicated and requires chemicals There are many types and high prices, it is difficult to automate management and the cost is high; Fu Guanglong and others published an article in 2012, using TiO 2 / Fly ash synergistically treats paraquat wastewater with Fenton reagent, TiO 2 / The preparation method of pulverized coal reagent is complicated, the cost is too high, and it is difficult to popularize

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