Fate of Harmful Chemical Substances in Landfill and Establishment of Safety Evaluation Method for leachate

自从发现了对人类有害的化学物质对地下水的污染后，一些化学物质如农药和有机溶剂被添加为环境标准的控制对象。在垃圾填埋场及周边地区的地下水中也检出了塑料增塑剂和阻燃剂，渗滤液的安全性成为公众关注的问题。因此，我们选择了诱变剂试验作为有害化学物质，特别是致癌物的检测方法，并对渗滤液的致突变性进行了检测。结果表明，诱变剂试验是垃圾渗滤液安全检测的有效方法，但诱变剂的提取、抑制剂的去除等问题亟待解决。此外，还可以通过废物的生物分解来产生和降解诱变剂。因此，我们试图解决这些问题，并在垃圾填埋场清除诱变剂的命运。本研究的结果如下：1)通过调节pH到2，大部分诱变剂被浓缩；2)蓝色粘胶吸附不能浓缩所有渗滤液中的诱变剂；3)在渗滤液中诱变剂的回收率方面，溶剂萃取法和CSP树脂吸附法没有太大差异；4)内标法可能不能作为抑制诱变剂试验的校正方法；5)10%2PrOH/正己烷可以去除诱变剂试验的抑制物；6)垃圾在好氧条件下的生物降解，特别是硝化过程，是垃圾在填埋层中产生和降解诱变剂的过程。7)硝化作用和反硝化作用都会产生诱变剂。8)在含有焚烧残渣的垃圾填埋层中，硝基芳烃可能是作为诱变剂产生的。

Since the pollution of underground water by the chemcial substances, which are harmful to man, was found, some chemical substances such as pesticides and organic solvents have been added as the control subjects of environmental standard. The plasticizers and fire retardants of plastics also were detected in the undergraoud water in the landfill site and the surrounding areas and the safety of leachate become the public concern. So, we selected a mutagen test as the detection method of harmful chemical substances, especially the carcinogen, and surveyed the mutagenicity of leachate. From the results, it was cleared that the mutagen test was useful method as the safety indicator for leachate, and that some problems opf mutgen test, such as the extraction of mutagen adn teh removal of inhibitermmust be solved. Moreover, the mutagen may be produced and degraded by the biological decomposition of wastes. So, we tried to solve these problems and to clear the fate of mutagen in the landfill site. The results of this study are as follows ;1) Most of mutagens were concetrated by the adjustment of pH to 2.,2) Blue rayon adsorption could not concentrated the mutagens from all of leachate.,3) On the recovery percentages of mutagen from leachate, there were not great difference between the solvent extraction and CSP resin adsorption.,4) The internal standard method may be unuseful as a correction method against the inhibitation for the mutagen test.,5) The inhibiters of mutagen test can be removed by 10%2PrOH/Hexane.,6) The production and degradation of mutagens in the landfill layr occur by the biodegradation of wastes in an aerobic condition, especially the nitrification process.,7) The mutagens were not only produced by the nitrification, but also the denitrification.,8) It is suggested that Nitroarene may by produced as the mutagen in the landfill layr contained incineration residues.