Contrast The Organochlorine Pesticides In Different Mendia In Karst Area

Organochlorine pesticides (OCPs) is a kind of the persistent organic pollutants (POPs), which play the role of endocrine disruption. Owing to its characteristics, such as the biological accumulation, highly toxic, the long-time residue and semi volatile, Organochlorine pesticides are serious harm to the health of human beings and ecological environment. The study of karst has been playing an important position in our country. The unique distribution pattern of karst area has made the ecological environment of karst areas very vulnerable. Once destroyed, it is hard to recover. In recent years, human activities have been made serious harm to ecological environment of karst areas.In this article the Nanshan laolongdong underground river basin which located at Chongqing has been taken as a study case. It aims at studying the influencing factors of organochlorine pesticides to provide a theoretical basis for governance environmental pollution in karst area.This research mainly includes three aspects:Firstly, through collecting the water, sediment, and surface soil of laolongdong underground river basin to analysis the composition and the possible sources of OCPs. Secondly, the article comparison of OCPs between different water of laolongdong underground river basin. Lastly, study the OCPs migration and transfer process. The results as below:1. The HCHs in water, surface soil, sediments mainly comes from lindane, the historical usage of lindane may cause HCHs pollution in surface soil and sediments. The technical DDTs maybe caused DDTs pollution. There have new DDTs input the water, DDTs was dechlorinated under anaerobic conditions. There have new dicofol input the surface soil and sediments, DDTs was dechlorinated under anaerobic conditions.2. The results showed that the concentrations of OCPs have obvious seasonal difference which the dry season is higher than the rainy seasons. Due to the impact of the soil for OCPs, relative to the groundwater, surface water can more accurately reflect the source of HCHs when using a ratio method to judge HCHs source. Due to the effect of soil, the percentage composition of DDTs, HCHs has changed. The difference of OCPs between underground water and surface water is due to they are in different environment. The average concentration of HCHs in recharge area is higher than the mainstream, the average concentration of DDTs, OCPs in underground water is higher than the surface water. The main component of HCHs in recharge area and mainstream showed differences. The recharge area is given priority to with P-HCH may be due to the affected by the water infiltration process in the soil, and the degradation have occurred in the process. The mainstream is given priority to with a-HCH may be due to the affected by the use of lindane. The primary components of DDTs in the sample point are consistent; it may be due to the affected by the use of technical DDTs.3. The similar composition of OCPs between Underground River and other waters showed Surface water and eprkarst spring play an important role on contamination in the river. Analysis of the composition of OCPs in surface sediment, the sediment of underground river, surface soil showed that the OCPs in the sediment of underground river mainly comes from the upstream water, surface soil and surface sediment.