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Thesis basin key pollution sources nitrated aromatics wastewater targeted to human health and ecological security, based on the wastewater throughout treatment and toxicity reduction, developed the nitration wastewater toxicity full cut technical methods. Specifically, the overall control system mainly by the new zero-valent iron (ZVI) - Fenton (Fenton) pretreatment, biological treatment and resin depth processing of three parts. Pretreatment process bottlenecks restricting the overall treatment effect of wastewater and running costs, however there is still a lack of a cost-effective nitrification wastewater pretreatment technology. This article attempts to adopt a new ZVI-Fenton integrated process as nitration wastewater pretreatment technology, and the study of the process on the characteristics of poison pollutant nitrobenzene (NB) transformation and removal mechanism and toxicity reduction. New ZVI reactor operation mode full hybrid, not only effectively avoid the traditional ZVI bed (tower) easy to plug the engineering problems, and has the advantage of reduction efficiency easy to control. NB reduction conversion rate can be adjusted by changing the the novel ZVI reactor ZVI mass concentration and solution pH value. NB reductive transformation rate increases to help reduce effluent toxicity, however, difficult to restore toxic pollutants in wastewater still makes the wastewater has strong toxicity. Compared ZVI reduction, Fenton oxidation Degradation in a wider variety of toxic pollutants, but it may form more poison byproduct in the oxidation process, however. For example, traditional Fenton oxidation NB removal rate of 97%, resulting in up to 5% of the 1,3 - dinitrobenzene (1,3-DNB) nitrification byproducts, its toxicity is about 30 times nitrobenzene toxicity or so. Accordingly, poisoned by the formation of byproducts is the limiting factor for reduction of toxicity of the conventional Fenton oxidation. Novel ZVI-Fenton process can be effectively suppressed produce 1,3-DNB, mainly due to the reduction product of ZVI process and Fe2 · NO2 inhibition. When the ZVI NB restore conversion rate 48% ,1,3-DNB yield relative reduction of 92% (from 5% to 0.4%), waste water toxicity also will significantly reduce. In order to verify the feasibility of the application of the novel ZVI-Fenton integrated process, nitrification wastewater for a large chemical company, to carry out a comparative study of several typical pretreatment process. Novel ZVI-Fenton integrated process than the ZVI column and traditional Fenton oxidation treatment effect has obvious advantages, novel ZVI-Fenton integrated process toxic unit (TU) reduced by 83%, the ZVI column cut only 35%, traditional Fenton process for 59 percent. In addition, the novel ZVI-Fenton integrated process processing cost is only about 1/3 of the enhanced Fenton oxidation. Full control \After pretreatment of industrial wastewater TU dropped from 6.3 (extremely toxic) 1.77 (toxicity) the biodegradability (BOD5/CODcr) increased to 0.45, can be further processed into biological systems. Biological treatment process of wastewater DOC and toxicity have good removal of biochemical tail water, however, is still residual trace amounts of toxic pollutants, manifested as toxic (TU 1.49), and therefore need the depth of processing in order to protect the water quality safety. The use of enhanced coagulation and adsorption (composite functional resin, activated carbon), or to strengthen the integration process of coagulation and ion exchange, not only to further remove the DOC, biochemical tail water toxicity can be reduced to no acute toxicity (TU below 1). Oxidation disinfection process, easy to toxic disinfection byproducts, with adsorption techniques (such as the composite functional resin, activated carbon) coupled removed before non-toxic emissions.
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