聚丙烯小球对人工垂直潜流湿地氮磷去除性能的优化研究

采用页岩和香蒲(Typha latifolia L.)构建人工垂直潜流湿地处理津河富营养化水体,并用聚丙烯小球替代部分页岩研究其对垂直潜流湿地氮磷去除性能的影响.设计水力负荷800 mm/d,理论水力停留时间12h.试验期间(2006-06～2006-11),氮磷月平均去除率在8月份达到最大值.与全页岩湿地相比,聚丙烯小球使氨氮(NH 4-N)、总氮(TN)、溶解性活性磷(SRP)和总磷(TP)月平均去除率分别提高13.38%、8.9%、9.29%和8.25%,使用聚丙烯小球能够有效提高人工垂直潜流湿地氮磷去除效率.试验结束后收割香蒲地上组织(茎和叶),测定地上组织生物量及茎、叶中的氮磷含量.结果表明,聚丙烯小球虽然抑制香蒲地上组织生物量的增加,但却能够有效提高茎、叶中氮磷含量.通过收割香蒲地上组织可使TN和TP去除分别增加29.382 g·m-2和13.469 g·m-2.

Optimization of Nitrogen and Phosphorus Removal in Vertical Subsurface Flow Constructed Wetlands by Using Polypropylene Pellet as Part of Substrate

Constructed wetlands experiments were conducted by using shale and Typha latifolia L as vertical subsurface flow constructed wetland substrate and plant for eutrophic Jin River water treatment, and replace part of shale with polypropylene pellet to investigate its effect on nitrogen and phosphorus removal. In this study, hydraulic loading rate was equal to 800mm/d; theoretic residence time was equal to 12 h. During the entire running period, maximal monthly mean ammonia-nitrogen (NH4+-N), total nitrogen (TN), soluble reactive phosphorus (SRP) and total phosphorus (TP) removal rates were observed in August 2006. In contrast to the full shale used wetland, polypropylene pellet enhanced ammonia-nitrogen, total nitrogen, soluble reactive phosphorus and total phosphorus removal: 13.38%, 8.9%, 9.29%, and 8.25%. After finishing the experiment, aboveground plant biomass (stems and leaves) of Typha latifolia L was harvested, and its weight and nutrient content (total nitrogen and total phosphorus) were measured. Analysis of aboveground plant biomass indicated that polypropylene pellet restrains the increase in biomass but stimulates assimilation of nitrogen and phosphorus into stems and leaves. The subsequent harvesting of the plants resulted in the additional removal of total nitrogen and phosphorus of about 29.382g.m-2 and 13.469g.m-2, respectively.