Study On Treatment Of Water Of Enclosing River In Baosteel With Constructed Wetland And Its Plant

The water of enclosing river in Baosteel was studied and the research mainly included three aspects as follows:(1)(?)aboratory experiment of the water using the constructed wetland.(2)Plant composition in the constructed wetland.(3)Pilot experiment of the water using the constructed wetland.The main conclusions are listed as below:Firstly,the temperature,conductivity and pH of the river water were slightly varied when treated by the constructed wetland,while it was much effective in eliminating the chemicals,such as Fe,Mn,COD,NH₃-N,TP,NO₃^--N,with the average removal rate being 96%,95%,93%,55%,78%,93%and 94%,respectively. When the HRT was shortened to 2 days,the indexes of Fe,Mn and turbidity of the effluent could meet to"The reuse of urban recycling water-Water quality standard for industrial uses"(GB/T 19923-2005).Secondly,HRT had little effect on eliminating various pollutants when ranging from 5 days to 2 days.Being planted or not and changes of season and temperature were obviously affect the removal effect of NO₃^--N,but it had little effect on other pollutions.The removal effect was also little affected by flow pattern.The constructed wetland filled with manganese sand was effective in eliminating Fe,Mn, turbid meter,COD,NH₃-N and TP.Thirdly,the quantities of Fe and Mn adsorbed by the plants were relateively large with proportions about 6.1%to 28.1%and 1.5%to 56.5%,respectively,while the absorption quantities of N and P by the plants took the proportion only less of 0.1%in the whole absorption quantities by constructed wetland.The plants grew better in the wetland filled with gravel than the one filled with manganese sand,and the plants in the former wetland adsorbed more Fe and Mn than the latter.Fourthly,the pilot experiment showed the same rules as the laboratory experiment for the removal of pollutions and the effect of HRT,temperature and season.Its average removal rate of Fe,Mn,Turbidity,NO₃^--N,COD and TP were 95%,90%,91%,76%,37%,46%and 68%,respectively.The indexes of Fe,Mn and turbidity of the effluent could also meet to"The reuse of urban recycling water-Water quality standard for industrial uses"(GB/T 19923-2005)under the condition ofHRT=1.5d.Fifthly,there were remarkably differences for different plants in the biological indexes such as plant height,wet weight,water ratio,element content and biomass, while there were little differences for the same plant in different corridors.The growing regions and areas of plants varied in two years with Typhacae and Cyperus slternifolius increasing mildly and Scirpus L.decreasing remarkably.Typhacae was the best plant for absorbing Fe,while Scirpus L.was the worst.Thalia dealbata and Typhacae were the best to eliminate Mn,while Scirpus L.was the worst.The removal quantities of Fe and Mn by reaping the plants accounted for about 1%to 3%and 3%to 7%of the whole quantities of wetland,respectively.