Study On Bioremediation And Ecological Restoration In Dishui Lake Diversion Channel

Dishui Lake is the representatives and a symbol of Shanghai Lingang New City,It is located in the southeast corner of Shanghai and adjacent to the East China Sea.In addition,it is the largest artificial Landscape Lake in china.The main way to refresh the lake water is to connect this lake with rivers nearby through C-Port and D-Port.The lake water is Lack of mobility.According to the water quality status monthly report provided by shanghai hydrologic central station and shanghai water environment monitoring center.The source quality of Dishui Lake was between in standardâ…£and inferior standardâ…¤,Based on chemical parameters as total phosphorus(TP) and total nitrogen(TN),the lake quality is now had been on the status of Low-Middle eutrophic condition,and tends to be eutrophic.According to the treating eutrophication water experience at home and abroad,improvement of diversion water quality channel plays a vital role in improving the environmental quality of lake water.Taking the C-Port,main diversion channel of Dishui Lake,as the research object. "Biological Contact Oxidation Process" "ecological floating islands" and "ecological riverbank" was used in the experiment site.To improve the water quality of diversion channel water environment,further improve the water quality of Dishui lake.The research results are followed:1.Biological Contact Oxidation Process was started in December 10,2007,during the process, it was 6.9-11.9℃.After 30 days,the removal rates of Ammonia-N were 54%-63.5%,the removal rates of other nutrients were 10%-15%,Bio-film becoming brown.It is means that the success of the bio-film cultivation.2.When the hydraulic retention time(HRT) is0.7d,day treatment water amount is 2.58×10⁴m³, Ammonia nitrogen removal rate was 47.3%,COD_Mn removal rate was 21.7%,purifying effect.will have a good deal results.3.The experimental period,the reed stem volume of nitrogen and phosphorus did not significantly change,maintains basically between 11.1-16.2 g/kg;Leaves of nitrogen and phosphorus content simultaneity reached the peak in the October 27,respectively 30.2g/kg and 2.6g/kg.Peak of Calamus stem nitrogen content had a little delay,appears in the November 17, was 27.6g/kg;and Phosphorus content reached the peak in the November 7,and was 3.68g/kg. Nitrogen content of cattail reached the peak in the November 17,was 14.4g/kg;Phosphorus content reached the peak in the November 27,was 2.12g/kg.Nitrogen content of Myriophyllum spicatum reached the peak in the November 17,was 39.3g/kg;Phosphorus content reached the peak in the October 27,was 3.3g/kg.Comprehensive consideration,the law of inside plant volume of nitrogen and phosphorus change with time can determine the best harvesting time when the end of October and early November.4.During 3 months after slope protection engineering by vegetation,Slope-protecting Plants grow well.After grows the 80d investigation to demonstrate,Live staking and live Fascine sallow's survival percentage was all above 95%.Among them,live staking sallow's plant height reached a highest value of 90cm,but live Fascine sallow's plant height was more than 100cm. Each all growed 3-5 adventitious root,the root diameter from 1-2mm to 3-5mm was different,the longest root surpasses 50cm,the root fibril was developed.The vegetation restored quickly,had built the suitable habitat for other species.Canadian goldenrod which is Alien Species on the sloping shore was under the effective suppression.Supplementary water treatment technology of Dishui Lake in this paper has an important practical significance and guiding role in protecting water environment,especially Dishui lake water quality.At the same time,this study also has an important theoretical significance and practical value in the development of domestic landscape water conservation technologies and protection works of similar cases.