The Distribution Of Organochlorine Pesticides In Danjiang Kou Reservoir Of The North Water Transfer Project Before Water Transfer

Persistent organic pollutants has the characteristics of carcinogenic, teratogenic, mutagenic effects and genotoxicity, and interfere human endocrine system, causing "feminization" phenomenon, existing in various environmental media widespreadly, such as rivers and lakes, sediments and soils. Organochlorine pesticides (OCPs) is one of persistent organic pollutants, which is first to be included in the Stockholm Convention.North Water Transfer Project is a national large-scale water diversion project to adjust the allocation of resources and the sustainable development of regional economy, as Danjiangkou Reservoir is the water source the North Water Transfer Project, the quality safety assurance of water and other related media is quite necessary. The surrounding environment of Danjiangkou Reservoir is a long-term agricultural environment, a variety of farming and tourism throughout the region, the OCPs from agricultural pesticide use and industrial use resulting residue can not be ignored. There were few reports about the OCPs residue on the Danjiangkou Reservoir water, sedimennt and the surrounding soil deposition; meanwhile, the large-scale diversion of water accumulation and tune out, which would greatly affect the physical and chemical properties of various media in the reservoir, which may cause secondary release of pesticides and pollution cycle, based on this,our research intends to study the residue characteristic of organochlorine pesticides in Danjiangkou Reservoir before and after water transfer of North Water Transfer Project,and to establish a diversion model of the system to provide guidance and reference of the basis for other large water diversion activities.This paperis was just the research of organochlorine pesticides of Danjiangkou Reservoir on the residual water, depositing sediment and the surrounding soil before, the possible sources of organochlorine pesticides and related factors. Studies are as follows:1. Establishment the multi-residue analytical methods of organicchlorine pesticides and study their distribution in water samples from Danjiangkou Reservoir of Middle Route Water Diversion Project before the water transfer. Sampling is in the entrance or intersection of the major tributaries in Hubei, Henan reservoir, dispersive liquid-liquid microextraction combined with gas chromatography (GC-ECD) to analyze20OCPs in water (surface water, pore water) of Danjiangkou reservoir.The results were:a-HCH, γ-HCH, p-HCH, hexachlorobenzene (HCB), p, p’-DDT, p, p’-DDD, o, p’-DDT, endosulfan Ⅱ, heptachlor, aldrin and endosulfan sulphate were detected in water samples, p,p’-DDT,endosulfan sulphate and endosulfan Ⅱ, p,p’-DDT,endosulfan sulphate were the main OCPs in surface water and core water, the total concentration range of OCPs in surface water and core water were ND-349ng L-1and ND-271ng L-1respectively. In all samples, the higher concentration of the sample point was D1(Danjiang Dam), D6(JunXian), D7(AiHe) in surface water, D3(LangHekou), H6(SongGang), H7(XiangYan Temple), H8(Xiao Taipingyang) in core water. Concentrations of OCPs residues are relatively low compared with other places, and the pollution is lighter, far below the national standard pesticide residue standards in drinking water.2. Establishment the multi-residue analytical methods of organicchlorine pesticides and study their distribution in sediments of Danjiangkou Reservoir, the sample sites of sediments were the same with the sites of water sample, related basic physical and chemical properties were studied, microwave-assisted extraction and dispersive liquid-liquid microextraction combined technology with gas chromatography (GC-ECD) to analyze the residue conditionof20OCPs in sediments. There were relatively high leverl of HCB, β-HCH,p, p’-DDD and p, p’-DDT, low leverl of2,4,5,6-tetrachloro-m-xylene,α-HCH, γ-HCH,§-HCH, aldrin, β-chlordane, a-chlordane, endosulfan I, dieldrin, o,p’-DDT and endosulfan sulfate in sediments; concentration range of OCPs was ND-5.44ng g-1, D6(JunXian), D11(YunYang gas station), H7(XiangYan temple) were the higher sampleing sites of total OCPs. OCPs in water and sediment were mainly affected by the daily life of nearby residents, operation and fuel supply vessels and fishermen fishing. The source of HCHs and DDTs determined by the proportion of its isomers, the use of lindane and industrial HCH were the source of HCHs, industrial use of DDT was for DDTs.3. The distribution, potential sources and persistence influencing factors of organicchlorine pesticides in surface soil around Danjiangkou Reservoir. Surface soil samples were collected from different usage types, which basic physical and chemical properties were studied; microwave-assisted extraction and dispersive liquid-liquid microextraction combined technology with gas chromatography (GC-ECD) to analyze the residue conditionof20OCPs in soils around the reservoir. According to the measured concentrations and detection frequencies, HCHs, DDTs, HCB and chlordanes were the predominant compounds in soil. EHCHs accounted for36.14%of total OCPs, followed by ΣDDTs (32.35%), HCB (11.86%) and chlordanes (6.18%). Concentrations of HCHs ranged from ND to3.006ng g-1in soils, relatively higher levels were observed in soil samples from Junxian wooden lands and Longkou orange tree lands.Concentrations of DDTs ranged from ND to5.189ng g-1, the main contaminated areas were distributed in Yunyang wharf cotton fields and Qinghui Pu orange tree lands. Source analysis showed that OCPs residues originated mainly from historical application, besides slight recent introduction at some sites; residual persistence factors exhibitedthat pH occupied large degree of influence over the TOC. Compared with the corresponding data from other places, although the region around Danjiang Kou reservoir is generally categorized as a relative slightly polluted area, which is a potential source of water OCPs due to the migration and runoff of OCPs.