【作者】 牟天明；

【导师】 陶长元； 安启洪；

【作者基本信息】 重庆大学 ， 化学工程， 2008， 硕士

【摘要】 氯代有机化合物是一类重要的难降解性有机化合物,具有极大的危害性。几乎所有的氯代有机物都有毒性,其中许多化合物被认为具有“致癌、致畸、致突变”效应;同时,由于很多氯代有机物具有高挥发性和类脂物可溶性,易被皮肤、粘膜等吸收,而对人体、动植物造成严重损害。为此,在使用及生产过程中形成的高浓度氯代有机物工业废水,严重影响人类健康和生态环境安全,已成为一类必需处置的废水。目前,国内外对高浓度氯代有机物废水的处理主要方法有物理法、生物法、化学氧化法和化学还原法等,但尚未成熟,还未找到一条合理、高效的处理工艺路线。本论文以二氯丁二烯生产过程的废液(简称二烯废液)为对象,开展降解氯代有机物的基础和应用研究,并以解决二烯废液脱臭和高浓度COD降解问题为研究目标。二烯废液的主要成分为:NaCl 30%、水55～60%、木焦油、N-亚硝基二苯胺、四氯丁烷、五氯丁烷、二氯丁烯、三氯丁烯、二氯丁二烯等5～10%。该混合废液呈碱性(pH=10～11),其CODCr值可高达32214.2mg/L,有非常强的刺激性臭味。针对该废液的特点,本论文探索性地开展了双金属还原法脱氯和Fenton氧化法降解COD的应用基础研究,初步建立了双金属还原--Fenton氧化联合工艺路线,实现了同时脱氯除臭和降解高COD的目的。论文重点研究了二烯废液基本性质,分析了二烯废液(提馏液、精馏液、混合液)组成及破乳步骤对后续处理过程的影响,探讨了双金属种类及用量、硫酸亚铁用量、过氧化氢用量、初始pH值、温度、反应时间等因素对二烯废液降解效果的影响。研究结果表明,二烯废液的可行处理过程为:先调节二烯混合废液pH值为5～7,加入零价铁和锌粉各0.5～1%进行反应;随后加入0.5～1%硫酸亚铁,然后逐渐滴加浓度为30%H2O2,控制双氧水和亚铁离子的摩尔比为4～6,反应温度为60～80℃。反应完成后,基本消除了刺激性臭味,COD剩余值可达到800mg/L以下。论文研究工作表明,双金属还原-Fenton氧化联合工艺,首先通过双金属还原法实现氯代有机物的脱氯,然后通过Fenton法氧化降低COD值,达到了预期的脱臭和降解COD的处理效果,为二烯废液的进一步工业化处理提供了理论依据和基础数据,也为高浓度氯代有机物废水的处理研究提供了新的途径,对于工业节能减排和生态环境保护具有积极的现实意义。更多还原

【Abstract】 Chlorinated organic compounds are harmful and resistant to degradation. Most of the chlorinated organic compounds are toxic with the negative effects of“carcinogenesis, teratogenesis and mutagenesis”. At the same time, many chloro-organic compounds are highly volatile and soluble as well as easily permealbe to skin, so they are dangerous in enviroment. So, industrial wastewater with high concention of chlorinated organic components heavily imperils human being’s health and zoology enviroment seriously. It had been an obligatory duty to purify this kind of wastewater. At present, the mostly used routs to purify the wastewater containing chloro-organic compounds include the physical method, the biological method, chemical oxidation process and chemical reduction. The investigations for a mature and economically process to deal with the chlorinated-wastewater are of importante meaning and are still under way.In the present work, the foundation research work as well as application exploring aimed to the dechloridation and degradation of the industry wastewater was carried out. The sample of wastewater was taken from a Chemical plant in Chongqing and it was formed in the dichloroprene producing process, so called neoprene wastewater. The compositon of this chlorinated hydrocarbon wastewater is as follows, NaCl (30%), water (55～60%), wood tars, N-nitroso diphenylamine, tetrachloridebutane, pentachlorobutane, chlorinated compounds (5～10%) including dichlorbutene, trichlorobutene, dichloroprene, etc. It is oringinal a mixture with pH of 10-11, CODCr concentration of 32214.2 mg/L and with stongly odour. The goal of the present work is to deodour and reduce COD concentration. Regarding this neoprene wastewater, the foundation research work of a route combine with bi-metal reducing method and Fenton oxidation method was investigated. A novel route of bimetal reducing method incorporated with Fenton oxidation method for the dechloridation and the reducing COD values was established here. The dechloridation for deodour and the degradation of COD were simultaneously relized with this combined route.Experiments were carried out to explore the factors associated with the COD removal ratio and deodoration by the combined process of bimetals reduction and Fenton oxidation. The feasible process was obtained by the purification of chlorinated hydrocarbon from the aspects of amount of bimetals, dosage of FeSO4 and H2O2 at various pH value. Results showed that the zero valent iron powder can have good performance in dechloridation and Fenton reagent can oxidize organics to remove COD. The satisfactory results were obtained by the following operation conditions. The pH value was adjusted to 5～7 by HCl and the zero valent iron and zinc powder were 0.5～1.0wt%, respectively. Then 0.5～1.0 wt% FeSO4 was put in the reactant followed by dropping in 20～30 wt% H2O2 gradually. Molar ratio of H2O2 to iron is in the range of 4～6 at optimal reaction temperature 60～80℃. The good purification performance was achieved with malodor removal and residual COD concentration 800 mg/L.The research work indicate that the route of bimetal reducing method combined with Fenton oxidation method can removel the chlorine from the chlorinated hydrocarbons mixture and reducing COD values by Fenton oxidation. This pilot study provides theory and basic data for the industry applications of treatment of neoprene wastewater. Further more, it also provide an new route for the treatment and purification of high concentration chlorinated organic wastewater.更多还原