Controlling Factor And Migration Characteristic Research Of Organic Pollutant In Typical Karst Underground Rivers

Karst aquifers contain much of the groundwater resource which is an important water source for many regions around the world. The karst underground water is an important water source in southwest China, because it containts about 1/4 underground water in 1/3 land approximately. As a result of special hydrology geology background in karst areas, the surface water and the ground water transforms rapidly, it causes the surface contamination fall into the underground systerm easily through karst tunnel cave, thus the groundwater is polluted. Specially at present, the karst underground water is polluted by industry, angriculture, mining and humanity sanitary sewage, which causes the underground water comprehensively in danger in southwest China. The organic fertilizer entered the buried river systerm which has alreaday threatened the people's life whose drinking water is karst underground water. Through investigating of POPs's origins, distribution characteristic, influence factor and migration characteristic is contributed to reduce and control the pollution of underground water, solve the drinking water problem maximumly and maintain the life and social stablility in karst areas.The research takes the Chongqing nanshan karst valley as research area, the human activity and angriculture production are the main activities. The main source of pollution in upstream Huang Jueya town has Chongqing Posts and telecommunications University, Chongqing second foreign language school, the large scale hospital, a spring water chicken street and the large-scale amusement park (is constructing), so the sewage flows through the trough valley area after the channel, in addition, midway farmland sewage's interfusion enter the buried river piping system, thus the old natural tunnel buried river water quality.has seriously polluted. This research mainly contains three aspects:Through gathering the samples of underground water and surface deposite in different months, discussing the POPs's space and time distribution characteristic and the mutually transform rules between underground water and surface deposit; Gathering the upstream and downstream's surface deposit, analysing the soil organic carbon, the machinery composition, and discussing the POPs's influence factor in karst rivers; Through comparing with non-karst areas'POPs's migration characteristic, discuss the rule of POPs's migration in karse areas. Through gathering water and surface sediment samples in different months and analyze it'sOCPs and PAHs, we realized that both OCPs and PAHs are high. Moreover, the upstream POPs is higher than downstream, the dry season organic pollutant content is higher than the ample flow time, the organic pollutant contained in the surface deposit is higher than the water body.Through detecting the organic carbon, the soil machinery composition, we realized that the organic pollutant is mainly accumulated in the high soil organic carbon, the content of the thick silt is an important factor which will affect the distribution of the POPs.Through comparing the migration characteristic of POPs in surface sediment with non-karst areas, we found that the reduced degree of OCPs in downstream surface sediment is lower than Haihe river. Because the organic pollutant gets down gradually in the flowing process, the soil in non-karst area is thick, so the organic pollutant is absorbed in the process of flowing, and has experienced the year after year accumulation, which causes the content of OCPs in downstream is lower than upstream.