两类土壤铅的生物可给性及健康风险评价研究

发布时间：2018-05-17 19:40

本文选题：土壤 + 铅　；参考：《山西大学》2015年硕士论文

【摘要】：为了推进全国重金属污染防治的实施,开展污染土壤的健康风险评价已成为污染土地再利用的必要手段。传统健康风险评价体系过分保护人体健康,以致污染场地过分修复。研究者推荐采用生物可给性完善风险评价体系。目前,不同的体外方法设计原理和初始目的不同,且方法的选择缺乏标准、统一的原则。这不仅使得不同体外试验方法的结果缺乏可比性,也造成了对体外消化方法选择和使用的随意性。为了完成体外消化方法的统一化、标准化,本文选用的提取方法为五种常见的体外试验方法(PBET、SBET、IVG、RIVM、DIN法),供试土壤为两类性质差异较大的土壤。围绕常见的、分布广、危害大的铅元素,研究主要包括了酸性和碱性土壤铅生物可给性比较和体外方法的筛选、消化酶的提取作用及以生物可给性为基础的对生物质炭修复效果评价。主要结论有以下三点：(1)适合酸性和碱性土壤铅的体外试验方法主要为PBET法。PBET法对酸、碱土壤铅的生物可给性分别为13.5%-38.5%、5.4%-17.1%,与动物相关性较好,且从安全角度考虑PBET土壤筛选值142.9 mg·kg-1,320.9 mg·kg-1相对符合GB15618-2008居住用地标准和风险控制趋势。(2)试验分别比较了三种体外消化方法(PBET、IVG和SBET法)中添加消化酶和不添加消化酶时,土壤铅生物可给性的差异。结果表明,消化酶对不同类型土壤铅提取能力有差异：消化酶对碱性土壤铅提取作用影响较明显,对酸性土壤铅的提取作用影响无明显差异。同时揭示了胃蛋白酶和猪胆盐、胰酶对两类土壤铅提取作用较显著。(3)试验分别利用三种体外消化方法(PBET、IVG和SBET法)评估生物质炭修复效果。结果表明：第一从健康风险评价角度,对于非农业用地土壤修复生物质炭可能的最适添加量为2%-4%之间；对于高浓度铅污染土壤,生物质炭修复的效果不理想。第二不同体外试验方法影响评估生物质炭的修复效果,因此,选择合适的体外方法至关重要。
[Abstract]:In order to promote the implementation of heavy metal pollution prevention and control in China, health risk assessment of contaminated soil has become a necessary means for the reuse of contaminated land. Traditional health risk assessment system overprotects human health, resulting in excessive remediation of contaminated sites. Researchers recommend using bioavailability to improve risk assessment systems. At present, different in vitro method design principle and initial purpose are different, and the method choice lacks the standard, the unification principle. This not only makes the results of different in vitro test methods not comparable, but also makes the selection and use of in vitro digestion methods arbitrary. In order to unify and standardize the digestion methods in vitro, five common in vitro test methods were used in this paper. Around the common, widely distributed and harmful lead elements, the research mainly includes the comparison of bioavailability of lead in acidic and alkaline soils and the screening of methods in vitro. Extraction of digestive enzymes and evaluation of biomass carbon remediation based on bioavailability. The main conclusions are as follows: (1) the main in vitro test method for acid and alkaline soil lead is PBET method. The bioavailability of lead in alkaline soil is 13.5-38.5% -5.4- 17.1g, respectively, which has a good correlation with animals. Considering that the PBET soil screening value of 142.9 mg kg-1320.9 mg kg-1 was in accordance with the GB15618-2008 residential land standard and the risk control trend from the safety point of view, the experiments were conducted to compare three in vitro digesting methods, I. e., the addition of digestive enzymes and the absence of digestive enzymes, respectively. Differences in the bioavailability of lead in soils. The results showed that the ability of digestive enzymes to extract lead from different types of soils was different: the effect of digestive enzymes on the extraction of lead in alkaline soils was obvious, but there was no significant difference in the extraction of lead in acidic soils. It was also revealed that pepsin, porcine bile salt and trypsin had significant effects on the extraction of lead from two kinds of soils. The results showed that: first, from the health risk evaluation point of view, the optimal amount of biomass carbon remediation for non-agricultural soil was between 2- 4%, and for high-concentration lead-contaminated soil, the effect of biomass carbon remediation was not ideal. Second, different in vitro test methods affect the evaluation of biomass carbon remediation, so it is very important to select a suitable in vitro method.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X825

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