Research On Improvements Of Outlet Quality By Wetlands With Aeration Inside And Its Stoppage Control

Constructed Wetlands Treatment system is a new sewage treatment technology, it has developed rapidly because of solving the problem of high capital and operating costs of conventional sewage treatment process, especially in the western developed countries, and this technology is widely used. But wider use of wetlands is seriously constraint by the problem of low removal rate of nitrogen and phosphorus.There are many researching on improving the removal rate of nitrogen and phosphorus and preventing stoppage about the wetland. The results show that low dissolved oxygen is the mainly reason of low removal rate of nitrogen and phosphorus in the wetland system, Nitrification and denitrification of nitrogen and Fe2+ cannot be oxidized to Fe3+, together with PO43- to form stable compounds which affect the removal of phosphorus. SS and organic matter in wastewater was absorbed by fill on the wetland surface which resulting in sewage sedimentation is the main reason to cause the stoppage of wetlands. Therefore, wetlands were constructed to improve the dissolved oxygen by the aeration inside the wetland and process of ammonification- nitrification- denitrification of organic nitrogen by Microorganisms and oxidizing Fe2+ to Fe3+ so as to form stable compounds in wastewater. In this study, different plants were planted at different levels of wetland, and secondary wetlands were selected as the test site, by measuring the different removal effect of nitrogen and phosphorus in wastewater. Conclusions were drawn by studying the variation of dissolved oxygen, and removal effect of nitrogen and phosphorus and change in congestion in wetland:â‘ when aerating inside the wetland at 30cm, dissolved oxygen tends to saturation, the greater the pressure, the shorter the time requiredâ‘¡Aeration inside the wetlands can increase the removal efficiency of COD, and removal efficiency of Nitrogen and phosphorous is related with the depth of aerating. Aerating at 55cm can enhance the removal efficiency of Ammonia, TP, and 33cm turns opposite.â‘¢Studies have shown that aerating can reduce the water content of substrate and increase matrix porosity by comparing these two indicators with wetlands without Aeration system. Therefore, aerating inside the wetland can be improved the degree of wetland clogging to some extent.The innovation of this study is realized aeration inside the wetland.