Study On The Influencing Factors And The Polluting Characteristics Of Organochlorine Pesticides In Typical Irrigation Area Soils

It is known to us that the organic chlorine pesticides(OCPs) are the environment pollutants that should be controlled first.The OCPs are also typical continuous pollutants.They have the characteristics of difficult-degradation,semi-volatility,biology-accumulation and high-toxic.They can exist in the nature for a long time,and concentrate through the food chains.They are tremendously bad for human health and the environment.In recent years,plenty studing works about the OCPs residual conditions,distributions and characteristics in the surface layer soils of sewage irrigation,resurgent water irrigation and clear irrigation had been already done,but few works about OCPs residual conditions,distribution and characteristic in depth soils of different irrigation areas.this article was mainly about the condition of sewage irrigation area,resurgent water irrigation area and clear irrigation area,on the basis of American EPA standard method which examined OCPs , adopting GC-ECD gasphase chromatograph which examined the contents of the OCPs in different soil profiles, researching the OCPs migrating,transformating , mainly accumulating layers and the main factors of affecting them physical and chemical behaviors under different irrigating conditions.Firstly,this article carried on the drilling samples from the sewage irrigation area,the resurgent water irrigation area and the clear irrigation area and analising them,identified the main pollutants were:HCHs,DDTs, Aldrin ,HCBand Heptachlor in the three profile soils.p,p'-DDE andδ-HCH were the main isomer of DDTs the HCHs separately. HCHs,DDTs, Aldrin and HCB were mainly detected things of the surface soils, the detectable concentrations respectively were:28.20μg/kg,8.64μg/kg,1.15μg/kg,and they shown a phenomenon: Clear irrigation area < resurgent water irrigation area < dirty irrigation area;under the surface, HCHs, Aldrinand Heptachlor were the mainly detected things. The detectable concentrations of the totle OCPs in sewage irrigation were less than 1μg/kg ,the detected most concentration was 1.01μg/kg in resurgent water irrigation areas,compared with sewage irrigation and resurgent water irrigation, detected the most concentration of the clear irrigation was 4.54μg/kg .The totle OCPs contents shown a phenomenon : Clear irrigation area >resurgent water irrigation area>dirty irrigation area;from these phenomenons ,we could know the surface was the accumulating layers.The totle OCPs concentrations of the study areas were nearly same under the surface,but the mainly detected things had differently downward migration.The picking out rates of the heptachlor in the three profile soil were the highest, and the migration ability of it was the strongest.Secondly,this article compared the detectable concentrations of the total organic chlorine between in soils and in the water from irrigation in the study areas, found the both had good consistency,which illustrated the irrigation water was one of important inputing sources.Thirdly,this text used SPSS statistical analysis software to make samples relevant analysis to find the physical and chemical parameter of three typical irrigated area soils:clay mineral contents,clay contents and CEC had excellent correlation.At the same time,literary followed the stepwise regression analysis,obtained the multiple regression equation of the sewage and the reclaimed water irrigated areas: Yocps=0.569XTOC-0.632X Moisture content andYocps=0.637Xtoc-0.558X Moisture content. these two equations were very good reflecting that the moisture content of soil and TOC had much better correlation with the contents of organochlorine pesticides.this phenomenon was found in clear irrigation.