Study On The Water Pollution Control Engineering Of Baihua Lake, Guiyang

China is one of the13nations that have the lowest per-capita water resourcesallocation in the world. Lake is an important part of water resources, and the lakes inChina suffer a serious lake eutrophication issues now. Baihua Lake locates in thecentral of Guizhou province, is an important potable water sources of Guiyang City.But after the1990s, with the increasingly enhancement of human activities and therapid development of industry and agriculture, the water qulity of Baihua Lakedeterioration quickly, and threatens Guiyang’s drinking water security seriously.Although the water qulity has now recovered to Class III dut to the local govermentstrengthens the extents of treatment, the agricultural non-point source pollution andlake sediment is still a big problem to Baihua Lake. Therefore, this paper relies on thenational water pollution control and treatment technology major projects, mercurypollution control and water treatment technology and engineering demonstrationsub-topics, focus on Baihua Lake, studies on how to control the external and theinternal pollutions of Baihua Lake, Findings are as follows:(1) The main pollutants of the stabilization pond-constructed wetland system inthe inflow waters are TN and TP, and rural sewage and agricultural ranoff water arethe main sources. The highest concentration of ammonia and TP in the outflow waterrespectively are0.8mg·L-1and0.037mg·L-1, it can meet the requirements of Class IIIstandard, but the system has a worse removal efficiency in TN, the concentration isjust below1.6mg·L-1.The stabilization pond can stabilize the water quality, and helpto removal the pollutants.(2) Aeration can inhibit the sediment from releasing N and P, and its ammonia,TN and TP inhibitory effects are about30%,20%and25%better than the groupsthose without aeration. Sunlights has little effects in inhibiting the sediment fromreleasing TN, but it has a positive effect in inhibiting the ammonia released from thesediment. Otherwise, illumination has an approximately120%promotion effect in TP’s relesae compares with the groups that sheltering the sunlights.(3) The effects by using natural zeolite, natural soil, kaolin, biochar and limoniteas the covering layer to control ammonia and TN is as follows: biochar> limonite>natural soil> natural zeolite> kaolin, and the covering effects of TP is as follows:limonite> kaolin> natural soil> natural zeolite> biochar. Limonite covering layerhas a better effects in dealing with all the pollutants, but it will turn the water’s colourto light red. Biochar has the best ammonia and TN control effects, but it will sharplyincreases the overlying water’s TP contentration.(4) When using natural zeolite as the covring layer, when the values of particlesize, cover thinkness, sunlights and aeration respectively are20mesh,3cm, with nosunlihts and with aeration, it will get the best ammonia control effect. When the fourvalues respectively are20mesh,1cm, with no sunlights and with aeration, it will getthe best TN control effect. When the four values respectively are40mesh,2cm, withsunlights and no aeration, it will get the best TP control effect. When considering allthe three pollutants, the best values of the four factors respectively are20mesh,3cm,with sunlights and aeration. When using natural soil as the covring layer, when thevalues of the four factors espectively are20mesh,3cm, with sunlights and aeration, itwill get the best ammonia control effect. When the four values respectively are10mesh,2cm, with no sunlights and with aeration, it will get the best TN control effect.When the four values respectively are20mesh,1cm, with no sunlights and aeration,it will get the best TP control effect. When considering all the three pollutants, thebest values of the four factors respectively are20mesh,2cm or3cm, with nosunlights and with aeration.