Experimental Study On The Treatment Of Polluted River Water By Overland Flow Systems

Land treatment systems have been put into pratice for many years to treat polluted water. And it showed good efficiency for pollutant removal. This method has been gradually developed since 1980 in China. In land treatment systems, contaminants in water can be removed or degraded by the functions of substrate (soil), plants and microbes. Thus, the threats of polluted water to aquatic environment can be reduced. Besides, in some cases, the treated water can be reused.Overland flow system is one of land treatment systems. It has the low requirement for pretreatment. It is not limited by ground water level and doesn't have great effects on ground water. It can be used to treat various kinds of industrial wastewater and sewage. It can also be used as pretreatment system for other land treatment systems.In this thesis, pilot scale experiments using overland flow systems were carried out to treat polluted water from Xinyi River. The main research contents include: (1) The efficiency and ability of overland flow systems in treating polluted river water;(2) The differences of the purification efficiencies of different plant species; (3) Effects of different hydraulic loads, different pollutant loads and temperatures on purification efficiency; (4) The differences of pollutant degradation at different sections along the slope of the land treatment systems.The results show that overland flow systems have high removal efficiency in treating polluted river water, especially for the removal of ammonium nitrogen. Through experiments, several system parameters under special conditions were recommended, which will provide important reference for the further application of overland flow systems in the control of water environment of Xinyi River.