Ao Hongyi

Seasonal variation of water quality of Xinyunliang River,Dianchi Basin and the impact of the riparian ecological restoration

Xinyunliang River is one of the major rivers which flow into Lake Dianchi.Water quality of the river effects the ecological health and environmental safety of Lake Dianchi.We employed single factor pollution indexes to investigate the seasonal variation of the water quality and the main factors which affect the quality.We studied the impact of the riparian ecological restoration on the river water quality taking the lower reaches of Xinyunliang River as an example.The results showed that there were obvious temporal variations in the concentration of ammonia nitrogen,total nitrogen,total phosphorus and chemical oxygen demand.All of the indicates showed declined tendency from May to November which is coincided with the rainy season,and were increased and significantly higher than those from November to next years April,the dry season.The quality of the water is much worse than Grade Ⅴ.The removal efficiency of pollutant in timber pile banks was higher than that in vertical cement banks.The removal efficiency in summer is much higher than that in winter.

Simulation study on in situ purification of lake inlets with artificial floating bed

An in situ simulation study about river purification was carried out in Taige Canal from November 2009 to July 2010,using artificial floating beds which were planted by plants Canna generalis,Oenanthe clecumbens and Lolium perenne.The research showed that the artificial floating bed can purify the river water uninterruptedly.The removal rates are 5%-35%,5%-40% and 5%-20% for TN,TP and CODMn,respectively.The removal effects were better under the conditions of high temperature and the rapid growth of floating plants.Water exchange time in different seasons influenced the removal rates differently.Trend of removal loading with different temperatures and growing stages was similar to removal rates.However,the removal loading would increase with decrease of the water exchange time in any seasons.The main purification effects of artificial floating bed can remove the suspended solid and increase the Secchi depth,so that the particulate nutrient can be removed.In summer,it can removed dissolved phosphorus and ammonia nitrogen significantly.The floating bed had only few effects on the nitrate and nitrite nitrogen.Effects of artificial floating bed on the cycles of nutrients by the changes of physical and chemical environment deserve to pay more attentions.