Research On Analysis Of Current Water Environmental Quality And Controlling Strategies In Dongguan City

With the development of economy in Dongguan city, the water in the city was seriously polluted. To protect water resources and realize the sustainable development, it's indispensable to research on analysis of current water environmental quality and Controlling Strategies in Dongguan city. In this study, surface water and shallow groundwater were regarded as a system. The study laid emphasis on the Dongjiang River and shallow groundwater, in order to understand the current water environmental quality fully and research the changes of water environmental quality, and we also investigated the pollution sources. By means of regression analysis, we studied the impact of the contaminated surface water upon groundwater and the variation characters of water quality along the Dongjiang river-way in Dongguan. On the basis of the above-mentioned work, the proposals were put forward to protect the water environmental quality from being polluted.The results obtained demonstrate:(1) In Dongguan city, most of rivers except the Dongjiang River were polluted so seriously that the water quality was below V class level. The seven middle-scale reservoirs all were contaminated in different degrees and all water quality couldn't match the aim of II class level. Drinking water source was lightly polluted by organic contamination, but its quality was relatively good.(2) The quality of shallow groundwater was worse. Among all the spots monitored, only 8% of water quality could reach III class level, others belong to IV or V grade water quality. On the whole, groundwater quality in the middle of the city is better than in the northeastern and the western part of city.(3) In Dongguan City, the majority of pollutant in Dongjiang River comes from coastal and hilly area. Industrial and domestic pollution sources were also main ones to the Dongjiang River. Therefore, it is very important to get some countermeasures to treat the areas and the pollution sources above-mentioned.(4) By analyzing the value of pH and the content of BOD5, CODmn, TP and NH3 - N in the river water, we find out the variation rules of pollutant along theDongjiang river-way in Dongguan. Moreover, we also know that from upstream to downstream, the water quality of Dongjiang becomes worse gradually.(5) Coupling water quality of groundwater and surface water in Dongguan City, we find that groundwater in western river-net was polluted seriously by the surface water above, a transparent linear correlation between them, while there is no such relationship between groundwater and surface water in middle and eastern areas.