重庆地区有机化工精馏残渣污染特性及其环境风险评价

发布时间：2018-09-12 15:22

【摘要】：在有机化学工业生产过程中,通过精馏分离技术获得有用产品或中间产物的同时,大多还会在塔釜产生一定量的残渣或者残液,其中常含有较多杂质以及有毒有害物质,在我国危险废物管理中常称其为精馏残渣(HW11)。随着有机化工行业的发展和精细化率的提高,精馏残渣产生量也在不断增加,但目前国内对精馏残渣还缺乏系统的研究,管控措施还很薄弱。因此,通过对典型有机化工企业进行调研,深入分析精馏残渣产生环节和污染特征,并对其组分进行分析,进而开展残渣的健康风险评价,具有十分重要的意义。论文在总结典型有机化工企业调研结果的基础上,进一步对所采集的残渣样品进行分析。精馏残渣多为粘稠的焦油状液体或固体,且成分复杂,残渣中的主要污染物一般可分为苯系物、多环芳烃、卤代物、重金属和其他类。运用风险评价指标体系,分别用线性和指数型两种评分法对精馏残渣中的五种特征污染物做风险等级评定,两种评价方法结果都表明多环芳烃和苯系物的风险等级最高,属极高风险等级。采用潜在生态危害指数法定量评价固态精馏残渣中重金属的环境污染风险,PTA精馏残渣的潜在生态风险等级为强,Ni为主要的污染因子,潜在生态风险指数为474.85,并且Ni、Cr、Zn、Cu是普遍存在于精馏残渣中的污染隐患。按暴露途径的不同将残渣中的污染物分为非挥发性和挥发性污染物两种,分别对其开展人群健康风险评价。以重金属为例研究精馏残渣中非挥发性污染物的健康风险。研究结果表明被评价的四种精馏残渣中重金属的经口摄入途径致癌风险值分别为8.55E-04、4.91E-04、4.48E-03、4.19E-04,致癌风险强。致癌污染因子是Cr和As,且As的致癌性比Cr强。计算得出这四种残渣每年导致的致癌人数分别为38.5、12.3、22.4、25.1。以挥发性和毒性较强的氯代烃为例研究精馏残渣中挥发性污染物的健康风险。研究结果表明被评价的三种精馏残渣中氯代烃的综合致癌风险值分别为3.62E-05、3.68E-06、9.81E-06。致癌风险主要来自呼吸途径,CCl4和C2HCl3是主要的污染因子,风险贡献率分别为66%和33%。计算得出每年受残渣污染导致的致癌人数分别为116、0.552、11.3,若甲烷氯化物的生产工艺得以优化,可使年致癌人数从116人减至3人。
[Abstract]:In the production process of organic chemistry industry, while obtaining useful products or intermediate products by distillation separation technology, most of them also produce a certain amount of residue or residual liquid in the tower kettle, which often contains more impurities and toxic and harmful substances. In China, hazardous waste management is often referred to as distillation residue (HW11). With the development of organic chemical industry and the improvement of refining rate, the amount of distillation residue is also increasing, but at present, there is still a lack of systematic research on distillation residue in China, and the control measures are still very weak. Therefore, it is of great significance to investigate typical organic chemical enterprises, deeply analyze the production and pollution characteristics of distillation residue, and analyze its components, and then carry out the health risk assessment of residue. On the basis of summing up the research results of typical organic chemical enterprises, the paper further analyzes the residue samples collected. The residue of distillation is mostly viscous tar liquid or solid, and the composition is complex. The main pollutants in the residue can be divided into benzene series, polycyclic aromatic hydrocarbons (PAHs), halogenates, heavy metals and other kinds. Using the risk evaluation index system, the five characteristic pollutants in distillation residue were evaluated by linear and exponential scoring methods respectively. The results of two evaluation methods showed that polycyclic aromatic hydrocarbons (PAHs) and benzene series had the highest risk grade. Very high risk level. Environmental pollution risk of heavy Metals in solid Distillation residue was evaluated by using potential Ecological Hazard Index method. The potential ecological risk grade of PTA rectification residue was strong Ni as the main pollution factor. The potential ecological risk index is 474.85, and Ni,Cr,Zn,Cu is a common pollution hazard in distillation residue. The pollutants in residue were divided into non-volatile and volatile pollutants according to different exposure pathways, and the population health risk assessment was carried out respectively. Taking heavy metals as an example, the health risk of non-volatile pollutants in distillate residue was studied. The results showed that the carcinogenic risk of heavy metals in the four kinds of rectified residue was 8.55E-04 ~ 4.91E-04N 4.48E-03N 4.19E-04, respectively. Carcinogenic pollution factors are Cr and As, and As is more carcinogenic than Cr. The number of carcinogens caused by these four residues was calculated to be 38.5% 12.322.4% 25.1 respectively. The health risks of volatile hydrocarbons in distillate residue were studied by taking chlorohydrocarbons with high volatility and toxicity as an example. The results showed that the comprehensive carcinogenic risk values of chlorinated hydrocarbons in the three kinds of distillation residues were 3.62E-05n3.68E-06n9.81E-06respectively. CCl4 and C2HCl3 are the main pollution factors, and the risk contribution rates are 66% and 33% respectively. It is calculated that the number of carcinogens caused by residue pollution is 116U 0.552c11.3 per year. If the production process of methane chloride is optimized, the number of carcinogens per year can be reduced from 116 to 3.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X783;X82

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