Study On Toxicity Identification Evaluation And Casusality Analysis Of Laohe River Sediment

Sediments can accumulate pollutants in water, and with the overlying water disturbance,it will re-release pollutants into the water to form secondary pollution. This study adopts arepresentative selection of benthic animal chironomid larvae as model organisms, and usessediment toxicity screening assessment methods (TIE) to preliminary assess the sedimenttoxicity of Liaohe River’s main streams. Besides, it uses the vitro bioassay techniques to testthe content of aromatic hydrocarbon receptor effects, estrogenic effects and thyroid effects inthe sediment, providing a theoretical basis for the future prevention of pollution and sedimentcontrol.The10-day chironomid toxicity screening experiment shows that the surface sedimentsin Chaihe River, Changgouzi River, Fujiawobao Branch, Yanfeili Branch, Zuoxiao River,Yitong River, Pangxie River and Raoyang River, which are the main streams of Liaohe River,have higher toxicity to chironomid larvae.By TIE first stage adding zeolite analysis, Fujiawobao Branch, Yitong River, PangxieRiver and Raoyang River are the points with toxicity caused by ammonia nitrogen. By TIEfirst phase adding cation exchange resin analysis, in Liaohe River’s main streams,Changgouzi River, Fujiawobao Branch, Pangxie River and Raoyang River are the points withtoxicity caused by heavy metals. Through the analysis, it’s found that in Liaohe River’s mainstreams, the sediments pollution points caused by heavy metal are Changgouzi River, PangxieRiver, Raoyang River. And the pollution points caused by heavy metal Cd are ChanggouziRiver and Fujiabao Branch.TIE second stage toxicity identification test results show that the fort pay home nestdrained, dominate the river, crabs ditch, four sections around the sun river sediment toxicityof ammonia units are greater than1, indicating that ammonia is a major cause toxic pollutants;Changgou Son River section of heavy metals in sediments of as, Cd between TEC and PECvalues between content, indicating that Cd and as may cause toxicity of sediments; pay homeDiwobao drained section Cd concentration in sediments between TEC and PEC values room description Cd toxicity may cause sediments. Crab ditch and around Caiyanghe As contentbetween TEC and PEC values, indicating As sediments may cause toxicity...