Research On Removal Mechanism For Pollutant In Vertical-Flow Constructed Wetland

Owing to the wastewater treatment technology of constructed wetlands is a sort of simple, convenient and effective zoology treatment technology, it have wide appliance foreground because the constructed wetlands adapt to the situation of our country and the wastewater treatment in country and town. However, the wastewater treatment technologies of constructed wetlands have also some shortage, for example, pollutant removal mechanism, the improvement of removal effect, management, etc. According to the self character of vertical-flow constructed wetlands, this thesis research the pollutant removal mechanism and transforming characteristics, the pollutant improving effect and so on. It is importance to improve the pollutant removal effect, to optimize theoretic parameter in engineering design and to popularize the appliance range of the vertical-flow constructed wetlands.The following conclusions were concerned by this study.(1) Under the different temperature, this study ascertain the difference of the static adsorption ability of nitrogen and phosphorus and the actual removal ability of pollutant for different substrate. The constructed wetland, which is composed of some substrate that has abundant iron and calcium, will improve the removal ability of phosphorus pollutant. Otherwise, the constructed wetlands will improve the adsorption of nitrogen if it is composed of the aluminiferous substrate. In the initial operation stages of constructed wetland, the removal effect of total phosphorus is related to the max adsorption and Porosity of substrate. After that stage, it is related to the max adsorption of substrate.(2) Coal-ash, blast furnace slag and steel slag have better phosphorus removal adsorption because of the chemical adsorption. The surface of steel slag will come into beingCa₁₀(OH)₂(PO₄)₆, A1PO₄ and Fe₂PO₅ in the process of wastewater treatment. The surface of Coal-ash and blast furnace slag will come into being Ca₃ (PO₄ )₂ in the process of wastewater treatment.(3) In the substrate pole of singleness size, the biomembrane content be reduces...