Two low-rank coals, a sub-bituminous coal (BA) and a lignite (LY), were treated by hot water extraction (HWE) and hydrothermal treatment (HTT), and the environmental impacts of water-soluble matters eluted from coal by the HWE and HTT processes were evaluated in terms of TOC, mutagenicity, and the acute toxicity against freshwater organisms. When HWE was performed at 80°C, the degree of TOC for LY was much higher than that for BA. However, for HTT, the two coals gave comparable TOC values in L/S ratio of both 100 and 3. The HWE and HTT eluents of two coals were assessed by the Ames mutagenicity assay with Salmonella typhimurium TA100 and TA98 strains, and no notable mutagenicity was observed in the presence or absence of metabolic activation. When the mutagenicity of the 300ºC-HTT eluent of LY was analyzed, no notable mutagenicity was also observed. For the HWE and HTT eluents of LY, the acute toxicity test was carried out by use of Daphnia magna and Oryzias latipes. When the 80°C-HWE eluent was tested, almost no toxicity was observed for D. magna and O. latipes. However, when the HTT eluents were examined, the toxicity increased as the elevation of the HTT temperature, and the toxicity of organic matters dissolved in the 350°C-HTT eluent was comparable to that of reference phenolic compounds. From the FTIR analysis of organic matters eluted in the HTT eluents, it is found that the toxicity is caused by the presence of aromatic compounds with hydrophilic substituents, such as carboxyl and hydroxyl groups.
When base of landfill subsides, deformation occurs in the geomenbrane which is used as a component of liner. Usually, geotextile is being used to protect a geomenbrane from mechanical damage. This geotextile seems to have function as reinforcing the geomenbrane when it deform. A geogrid if it was used together with the non-woven textile may emphasize this reinforcing. This effect was examined here by placing a geogrid together with the geotextiles over soft geomembrane(FPA). Consequently, the amount of the maximum tensile strain creating in geomenbrane reduced to about 50% of that of in case of without geogrid and geotextile.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.