Study On Constructed Wetlands In Series For Treating Polluted River Water

Based on the south-to-north water diversion's requirement of treating sewage, contaminated water is collected in Qing'an River and sent to south of channel, then goes to the Yellow Sea. For the average water quality of Qing'an River is worse than V, it is necessary to dispose it in order to keep the quality of south of channel and the Yellow Sea.This dissertation was sponsored by the project of polluted water ecological treatment of Huaihe River from the environmental protection agency of Jiangsu province. After the high nitrogen concentration was determined as one of the main contamination characters, integrated vertical flow constructed wetland, surface flow constructed wetland, subsurface flow constructed wetland were used in series to dispose the polluted water from Qing'an River. In this dissertation, the effects of pollutants removed by constructed wetlands using different substrates and plants in series and its mechanism were discussed, and the microorganism community distribution and its' relevance with the nitrogen removal were also discussed. The main contents and conclusions of this dissertation are as follows:(1) The results of experiments of choosing substrates indicate that the slag is the best substrate of adsorption of ammonium and TP in the static adsorption experiments and the combination of sand and slag has the best effect of disposing contaminations in the dynamic adsorption experiments.(2) The results of experiments of choosing plants indicate that Scirpus tabernaemontani Gruel, Typha latifolia L., Acorus gramineus can all survive in Qing'an river, The capability of resuming oxygen are as follows, Acorus gramineus>Typha latifolia L.>Scirpus tabernaemontani Gruel.(3) The results of study on the effect of constructed wetlands' treatment indicate that the effects of removing COD_Mn,TN,NH₄⁺-N,TP these seven contaminations is good in IVFW, SFW, SSFW separately, the effect by the three types in series is better, the average efficiency is about 80%.(4) The results of study on the effect of removing nitrogen compounds and its mechanism indicate that the dynamic disciplinarian of the nitrogen compounds accords with the one dimension dynamic equation in IVFW, SFW, SSFW.(5) The results of study on the distribution of microorganism community and its relation with the efficiency of removing nitrogen compounds indicate that the disciplinarian of distribution of nitrifiers in three types constructed wetlands are as follows: the amount above > the amount middle > the amount below, the disciplinarian of distribution of denitrifying bacteria in three types constructed wetlands are as follows: the amount above < the amount middle