21. Bioassays for environmental impacts of water-soluble matters eluted from lignite

Abstract

When several lignites were subjected to hot water extraction (HWE) and hydrothermal treatment (HTT), the leaching of organic matters from coal was evaluated by total organic carbon (TOC). The degree of TOC in the HTT eluent was greatly increased as the HTT temperature was raised from 200 to 350℃. The extracts obtained from the HWE and HTT eluents for LY lignite were assessed in terms of Ames Salmonella mutagenicity assay and acute toxicity test for D. magna and O. latipes. The extract from the HWE eluent (EX-HWE) did not show any notable mutagenicity. However, an appreciable degree of mutagenicity after chlorination was observed for the EX-HWE. The eluent from HTT indicated a considerable acute toxicity for D. magna and O. latipes.