Research On The Dynamic Of Water Quality And Its Situ-monitorin In The Input Stream Of West Lake In Hangzhou

Our work was aimed at determining factors of water quality of West Lake in Hangzhou. Laboratory incubation and field in situ studies were conducted to determine the dynamic changes of brooks’nutrients, evaluate the effects of N and P losses in surface runoff of tea plantations on water quality of West Lake and initially establish the application of ion exchange resin capsule in water quality monitoring. The major conclusions are stated as follows:1) Research on West Lake brooks (Long Hongjian, Jin Shaxi, Mao Jiabu) water quality monitoring and N, P losses of the tea plantations. The results revealed that TN was the major factor in entered West Lake brooks, which was higher than the standard limit value of V type water. The highest TN concentration was observed in brook Long Hongjian that was4times higher than the standard limit value. The average concentrations of TN and TP were6.01,0.07mg/L in all the brooks and were5.47,0.48mg/L in tea plantations runoff. The TN and TP losses of tea plantations runoff had little influence on water quality of the West Lake, accounted for0.6%and5.2%of the entered N and P contents of the West Lake. The correlation analysis between tea plantations runoff and meteorological factors suggested that the N and P losses were significantly correlated with rainfall and the r value was between0.32and0.58.2) Laboratory simulation test was carried out to examining the application of ion exchange resin capsule in water quality monitoring. The results suggested that there was a significant difference in ions adsorption of ion exchange resin ball under different rotational speeds. In static state, the resin ball absorbed the ion completely after48h. The adsorption was fulfilled after4h with the speed100r/min. When the speed was increased to250r/min, the fully adsorption was fulfilled after0.5h. The recoveries of different ions from recycled ion exchange resin capsule were higher than90%.3) The in situ studies of ion exchange resin capsule used in the West Lake monitoring test. The results revealed that nitrate concentration of Long Hongjian brook was significantly higher than ammonium and TP concentrations in short-term and long-term cumulative absorption experiments. The three ions absorbed by resin capsule (RAQ value) were in accordance with ions concentration in water. High concentrations of ions in water have higher RAQ values. In contrast, low concentrations of ions have lower RAQ values. In the long term experiments, the RAQ of nutrients was positively correlated with the water flow rate (r=0.59、0.47、0.50). The RAQ of the NO3--N had positive correlation with concentration×flow rate(r=0.46). However, ammonia and total phosphorus had no significant difference with either concentration or flow rate. In short term experiments, except for nitrate, the RAQ of other water nutrients had positive correlation with concentration, flow rate, and concentration×flow rate. The major factors of the RAQ value were ion concentrations and water flow rate. The flow rate had greater influence on RAQ value. Therefore, the application of resin capsule was not suitable for the complex natural water that had diverse flow rate. It can be used in the water that had steady flow rate.