补充碳源强化潮汐流人工湿地脱氮效果的研究

Study on the enhancement effect of supplementary carbon source on nitrogen removal in tidal flow constructed wetland

针对人工湿地处理农村生活污水现存问题,构建了以加气混凝土、火山岩和砾石作为组合基质的潮汐流人工湿地(TFCW),探究进水碳氮比(C/N)对其去除污染物的影响;以河南省两种常见的农业废弃物(玉米芯和小麦秸秆)浸出液作为碳源,探究补充碳源对TFCW去除污水中污染物的强化效果。结果表明:提高进水C/N可以不同程度地增强TFCW对化学需氧量(COD)、总氮(TN)和总磷(TP)的去除率,但对氨氮的去除率影响不显著。玉米芯和小麦秸秆系列固体碳源浸出液前期释碳速率较快,结合浸出液的可生化性与反硝化性能,确定热处理玉米芯浸出液适合作为补充碳源。热处理玉米芯浸出液作为补充碳源能够使TFCW对各污染物处理达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。TFCW在农村地区的运用具备一定可行性,制备的固体碳源浸出液作为TFCW的补充碳源,能为农村地区人工湿地高效脱氮提供一种经济化方案。

According to the existing problems of rural domestic sewage treatment by constructed wetland,a tidal flow constructed wetland(TFCW) with aerated concrete,volcanic rock and gravel as the combined matrix was constructed,and the influence of influent carbon to nitrogen ratio(C/N) on pollutant removal was investigated.To explore the enhancement effect of carbon source leaching solution on the removal of pollutants in sewage,two common agricultural waste in Henan Province(corncob and wheat straw) were taken as the materials.The results showed that increasing the influent C/N could enhance the removal efficiency of COD,TN and TP by TFCW to varying degrees,but had no obvious effect on the removal efficiency of ammonia nitrogen.The early carbon release rate of leaching solution of corncob and wheat straw series solid carbon materials was faster.Combining with the experiment of biodegradability and denitrification ability of the leaching solution,it was determined that the heat treated corncob leaching solution was suitable for supplementary carbon source.The TFCW with heat treated corncob leaching solution as an supplementary carbon source could meet the Class 1A standard of “Discharge standard of pollutants for municipal wastewater treatment plant”(GB 18918-2002).The application of TFCW in rural areas had certain feasibility,and the prepared solid carbon source leaching solution used as the supplementary carbon source of TFCW could provide an economic scheme for efficient nitrogen removal of constructed wetlands in rural areas.