伽玛辐射降解环己丁酸的研究

发布时间：2018-04-24 23:13

本文选题：环己丁酸 + γ　；参考：《南京航空航天大学》2015年硕士论文

【摘要】：在油砂污水(OSPW)和炼油厂污水中,环烷酸是最常见的有毒成分之一。环烷酸对水生环境中的动植物具有较高的毒性,若未经处理直接排放,将对环境造成重大污染并危害人类健康。目前,以羟基自由基为基础的高级氧化技术已成为环境有机污染物降解的研究热点。γ辐射技术是一种新兴的高级氧化技术,因其具有处理效果好、无需添加任何化学试剂、无二次污染等优点而备受人们的关注,已广泛应用于环境中单一有机污染物和废水的降解研究。由于环烷酸组成复杂,常采用单一组分环烷酸作为替代物对其降解动力学进行研究。本研究选择环己丁酸作为研究对象,探讨了不同因素对伽玛辐射降解环己丁酸的降解效果的影响,并对其辐射降解机理进行了研究。本文完成的主要内容和得出的主要结果如下:(1)采用γ辐射对环己丁酸水溶液进行辐射处理,以化学需氧量(CODCr)、环己丁酸去除率作为表征手段,研究了环己丁酸初始浓度、初始p H值、吸收剂量对环己丁酸的伽玛辐射降解效果的影响。结果表明:在相同剂量条件下,环己丁酸初始浓度越高,CODCr去除率越低;酸性条件更利于溶液中CODCr的去除;环己丁酸的去除率随着吸收剂量的增加而增加,随着初始浓度的增加而降低;环己丁酸浓度随吸收剂量变化的曲线经拟合后呈线性关系(有较高的相关系数),表明环己丁酸辐射降解过程符合准一级动力学方程。(2)采用γ辐射与H2O2联合处理环己丁酸,在一定p H值和吸收剂量的条件下,研究了不同初始H2O2浓度对伽玛辐射降解环己丁酸的影响。结果表明:H2O2对γ射线辐射降解环己丁酸具有显著的增强效应,当p H=2.16、吸收剂量为9.75 k Gy以及H2O2初始浓度为1 mmol?L 1时,其对40 mg?L 1环己丁酸的辐射降解的促进效果较好。(3)采用γ辐射对环己丁酸进行辐射降解的方法,研究了环己丁酸的伽玛辐射降解的机理。通过加入自由基清除剂(硝酸钠、亚硝酸钠和叔丁醇)对辐射降解效果的影响研究,得出环己丁酸的辐射降解机理主要以羟基自由基氧化为主,羟基自由基在辐射降解过程中比氢自由基、水合电子起到更重要的作用;通过紫外分光光度计(UV-vis)、傅里叶红外光谱仪(FTIR)和气相色谱质谱联用仪(GC-MS)的测试,得到了主要的六种降解产物,其质荷比m/z分别为92、106、98、112、140、和142,并推导了环己丁酸伽玛辐射降解的途径。
[Abstract]:Naphthenic acid is one of the most common toxic components in oil sand wastewater and refinery sewage. Naphthenic acid is highly toxic to animals and plants in aquatic environment. If discharged directly without treatment, it will cause serious pollution to the environment and endanger human health. At present, the advanced oxidation technology based on hydroxyl radical has become a research hotspot in the degradation of environmental organic pollutants. Gamma radiation technology is a new advanced oxidation technology, because of its good treatment effect, no need to add any chemical reagents. Due to the advantages of no secondary pollution, it has been widely used in the degradation of single organic pollutants and wastewater in the environment. Because of the complex composition of naphthenic acid, a single component naphthenic acid is often used as substitute to study the degradation kinetics of naphthenic acid. The effects of different factors on the degradation of cyclohexanoic acid by gamma radiation were studied, and the degradation mechanism of cyclohexanoic acid was studied. The main contents and results obtained in this paper are as follows: (1) 纬 radiation was used to treat cyclohexanoic acid aqueous solution. The initial concentration of cyclohexanoic acid was studied by means of chemical oxygen demand (COD) and removal rate of cyclohexanoic acid. Effects of initial pH and absorbed dose on gamma radiation degradation of cyclohexanoic acid. The results showed that the higher the initial concentration of cyclohexanoic acid was, the lower the removal rate of COD _ Cr was, the more favorable the removal of CODCr was to the acidic condition, the more the removal rate of cyclohexanoic acid was increased with the increase of the absorbed dose, the higher the initial concentration of cyclohexanoic acid was, the lower the removal rate of COD _ (Cr) was. With the increase of initial concentration, it decreases. The curve of cyclohexanoic acid concentration with absorbed dose showed a linear relationship (with high correlation coefficient, which indicated that the degradation process of cyclohexanoic acid was in accordance with the quasi-first-order kinetic equation. 2) 纬 radiation combined with H2O2 was used to treat cyclohexanoic acid. The effects of different initial H2O2 concentrations on the degradation of cyclohexanoic acid by gamma radiation were studied under certain pH values and absorbed doses. The results show that: h _ 2O _ 2 has a significant enhancement effect on 纬 -ray radiation degradation of cyclohexanoic acid, when pH 2.16, absorbed dose 9.75 kGy and initial concentration of H2O2 1 mmol?L ~ (-1). The mechanism of 纬 -irradiation degradation of cyclohexanoic acid was studied by means of 纬 -radiation method to promote the radiation degradation of cyclohexanoic acid for 40 mg?L ~ (-1) cyclohexanoic acid. The effects of free radical scavengers (sodium nitrate, sodium nitrite and tert-butanol) on the radiation degradation of cyclohexanoic acid were studied. It was concluded that the main mechanism of radiation degradation of cyclohexanoic acid was hydroxyl radical oxidation. Hydroxyl radicals play a more important role in the process of radiation degradation than hydrogen free radicals, and hydrated electrons play a more important role. The determination of hydroxyl radicals in the process of radiation degradation is carried out by UV spectrophotometer, Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS). Six main degradation products were obtained, whose mass charge ratios m / z were 92106, 98112140, and 142.The methods of gamma radiation degradation of cyclohexanoic acid were deduced.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X74

【相似文献】