Study On Sedimentation & Release Rules Of Nitrogen & Phosphorusin In The Three Gorge

The article chooses the Yangtze River (collected at Chuqimen section) to soak the tested clay (collected at Yunyanshuangjiang Bridge section of Xiao River) to research the N&P sedimentation & release relationship, and the mass ratio of water to soil is 10:1.Through a series of experiment, it is found that the sedimentation & release of TN and TP is related with electrical conductivity, water temperature, pH, TN concentration and TP concentration in water. With the rising of electrical conductivity of water, the release capacity of TN rises too. With the rising of water temperature, the release values of TN and TP rise. If pH values is lowered, the release capacity of TP is enhanced; and on the contrary, if the pH value is raised, then its release capacity will be lessen. The release capacity of TP basically has no changes on the condition of pH values between 3.98 and 10.07, but its release capacity rises extremely obvious if pH values is above 11.05. When the TN concentration is below 15.80 mg/1, the TN will release into the water, and with its lowered concentration, the release capacity of TN is increased. If the TN concentration on the range of 11.96 mg/1 and 15.80 mg/1, TN basically does not be released into the water; while above 19.93 mg/1, TN will be precipitated, and its sedimentation mass will increased with the increasing of TN concentration. TP will be released into the water when its concentration is below 0.015mg/l (TP concentration of Yangtze River); TP will be precipitated when its concentration is above 0.015 mg/1, and the sedimentation mass of TP will be precipitated and its sedimentation mass is directly related with the TP concentration. When the clay diameter is between 10 and 100 items, the TN and the TP releasing mass equals.