固废中典型有机物测定的前处理方法比选

发布时间：2018-06-02 21:03

本文选题：固体废物 + 前处理　；参考：《南京农业大学》2015年硕士论文

【摘要】：近十几年来,随着经济的高速发展,人们的生活水平日益提高,同时伴随着大量固体废物的产生,各行各业产生着各自不同的固体废物,他们含有的物质种类差异巨大,因此处理的方式也不一样。如果是普通性固体废物,可通过普通方法进行处理,若是特殊性固体废物,按照国家规定要求,必须经过特殊处理和特殊处置,以尽量减少对环境的污染,保护人们的健康。所以,固体废物在处理处置之前,必须进行危险性的鉴定。固体废物是否具有危险性主要是从以下几个特性进行鉴定的,第一,是否具有腐蚀性。第二,是否具有急性毒性。第三,是否具有浸出毒性。第四,是否具有易燃性。第五,毒性物质含量是否超标,鉴定方法为直接针对固体废物进行毒性物质含量测定,如果其中有一种或多种物质含量超标,则鉴定为危险废物。固体废物如具有五种特性中一种或多种,固体废物的鉴定结果就为危险废物。本论文针对危险固体废物鉴定中毒性物质含量测定展开研究,主要对固体废物中有机毒性物质测定过程中的前处理过程进行了深入的研究。分别从固体废物有机毒性物质的提取,提取后样品液的净化,上机测定前的浓缩三个方面进行了方法的优化研究。基于实验室条件,比较了几种不同的提取方法,几种不同的净化方法,几种不同的浓缩方法的效果。以自然土壤代替固体废物,分别添加一定浓度的以下几类固体废物中常需鉴定的几种有机毒性物质,有机磷化合物,有机氯化合物,多氯联苯,含氯烃化合物,代表物为甲基对硫磷、氧乐果、α-HCH、β-HCH、γ-HCH、δ-HCH、艾氏剂、七氯、七氯联苯、六氯苯十种物质。分别使用不同的提取方法,不同的净化方法,不同的浓缩方法,同时改变相关条件,测定其回收率。结果如下:(1)分别采用加速溶剂萃取仪提取法,超声提取法,机械振动提取法对10种添加的有机毒性物质进行提取,结果显示,加速溶剂萃取仪提取法效果最好,回收率最高,数据重复性也最好,其平均回收率和相对标注偏差分别为92.2%和6.06%。超声萃取效果次之,机械震荡的萃取效果最差,两者平均回收率分别为85.9%和79.5%。使用不同的单一和混合提取溶剂进行提取发现,丙酮/正己烷(1:1)的效果最好。每种提取方法的最佳提取时间分别是:加速溶剂萃取仪静态提取9min,超声提取分两次一次30min共60min,机械震荡提取分两次每次45min共90min。加速溶剂萃取的最佳提取温度是80°C。(2)提取后的样品液分别采用固相萃取柱和浓硫酸进行净化,经实验发现三种固相萃取柱中的Florisil(弗罗里硅藻土)填料柱和C_(18)硅胶柱效果比较好,HLB柱的效果一般,而采用浓硫酸净化效果也不错,唯一的问题是有些物质具有酸不稳定的性质,导致浓硫酸净化效果不佳,通过回收率,适用性和实用性等因数比较,固相萃取柱是最好的净化方式。(3)上机前的样品液采用氮吹法浓缩和旋转蒸发法进行浓缩,结果表明:两者平均回收率分别为98.9%和94.3%,相对标准偏差分别为3.2%和5.0%,氮吹浓缩的效果稍好。经实验研究可知两者各有优劣,氮吹法适合浓缩体积相对较小的样品且可一次处理相对较多的样品,但时间较长,旋转蒸发法适合浓缩体积相对较大的样品且速度相对较快,但损失相对较多而且容易交叉污染。(4)结论:对于研究的十种有机毒性物质来说,最佳的提取方法是加速溶剂萃取仪提取法,提取温度为80°C,提取时间为9min,提取溶剂为丙酮/正己烷(1:1)。最佳的净化方法是采用Florisil填料柱或C_(18)硅胶柱。最佳的浓缩方法是氮吹浓缩,浓缩温度为45°C。本论文的研究结果可对危险固体废物毒性物质含量测定的前处理方法提供基础数据和基础经验,从而为固体废物危险性鉴定方法提供科学依据。
[Abstract]:In the past ten years, with the rapid development of economy, people's living standard is increasing day by day. At the same time, with the production of a large number of solid waste, different solid wastes are produced in all walks of life. They contain a great variety of material, so the ways to deal with them are different. If it is a common solid waste, it can be entered through ordinary methods. If special solid wastes are treated, special treatment and special disposal must be carried out in accordance with the requirements of the state, so as to minimize pollution to the environment and protect people's health. So, before the solid waste is treated and disposed of, the risk must be identified. The risk of solid waste is mainly from the following characteristics. Identification, first, whether it is corrosive. Second, whether it has acute toxicity. Third, whether it has the leaching toxicity. Fourth, whether it has flammability. Fifth, the content of toxic substances exceeds the standard, the identification method is to determine the toxic substance content directly against solid waste, if one or more material content exceeds the standard, it will be used as a warning. As a hazardous waste. Solid waste, such as one or more of five characteristics, is a hazardous waste identification result. This paper studies the determination of toxic substance content in the identification of hazardous solid waste, and studies the process of the pretreatment of organic toxic substances in solid waste. Not from the extraction of organic toxic substances in solid waste, the purification of sample solution after extraction, and the optimization of three aspects of concentration before the test. Based on the laboratory conditions, several different extraction methods, several different purification methods and several different concentration methods are compared. Several organic toxic substances, organophosphorus compounds, organic chlorides, polychlorinated dimethoate, alpha -HCH, beta -HCH, gamma -HCH, Delta -HCH, aldrin, seven chlorine, seven chlorobiphenyl, and six chlorobenzene, were added to several kinds of organic toxic substances which are often identified in the following kinds of solid waste, respectively. The results are as follows: (1) 10 kinds of organic toxic substances are extracted by accelerated solvent extraction, ultrasonic extraction and mechanical vibration extraction, respectively. The results show that the extraction method of accelerated solvent extraction is effective. The best recovery rate and data reproducibility are the best. The average recovery rate and the relative annotation deviation are 92.2% and the 6.06%. ultrasonic extraction results are the worst. The extraction effect of mechanical shock is the worst. The average recovery of both of them is 85.9% and 79.5%. is extracted by different single and mixed extraction solvents, and acetone / hexane (1:1) is found. The best extraction time for each extraction method is the static extraction of 9min with the accelerated solvent extraction instrument, two times 30min co 60min by ultrasonic extraction, and the best extraction temperature of two times 45min Co 90min. accelerated solvent extraction by mechanical shock extraction, and the solid phase extraction column and sulphur respectively after the extraction of 80 degree C. (2). The effect of Florisil (Flori diatomite) packing column and C_ (18) silica gel column in the three solid phase extraction columns is better. The effect of HLB column is general and the effect of concentrated sulfuric acid purification is good. The only problem is that some substances have the character of acid unstable, which leads to the poor purification effect of concentrated sulfuric acid and through recovery rate. The solid phase extraction column is the best purification method compared with the practical and practical factors. (3) the sample solution before the machine is concentrated by the method of nitrogen blowing and rotary evaporation. The results show that the average recovery is 98.9% and 94.3% respectively, the relative standard deviation is 3.2% and 5% respectively. The effect of nitrogen blowing concentration is slightly better. The experimental study is known. Both have advantages and disadvantages. The nitrogen blowing method is suitable for a relatively small concentration of samples and can deal with relatively more samples at once, but the time is longer, and the rotary evaporation method is suitable for the relatively large concentration of the sample with relatively faster concentration, but the loss is relatively more and easy to cross pollution. (4) conclusion: for the ten organic toxic substances studied The best extraction method is the extraction method of accelerated solvent extraction instrument, the extraction temperature is 80 C, the extraction time is 9min, the extraction solvent is acetone / n-hexane (1:1). The best method of purification is using Florisil packing column or C_ (18) silica gel column. The best concentration method is the concentration of nitrogen blowing and the concentration temperature is 45 C.. The pretreatment methods for determination of toxic substances in solid wastes provide basic data and basic experience, so as to provide scientific basis for the identification of solid waste hazards.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X705

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