人工湿地植物对高盐废水中COD的去除作用

EFFECT OF WETLAND PLANTS ON COD REMOVAL FOR HIGH-SALINITY WASTEWATER

针对经生化处理的石油和精细化工工业区的工业废水盐含量较高、氮磷营养盐含量较低和COD含量较高的特点,构建了高盐度进水条件下表面流人工湿地的中试试验装置,考察了水葱、芦苇和香蒲在此类高盐废水中的生长状况,比较了三种植物混合试验单元与无植物试验单元对此类高盐废水中COD的去除效果,研究了高含盐量工业废水湿地系统内植物生长对微生物量的影响,以及植物在微生物去除COD过程中的作用。结果表明,高含盐量的工业废水对水葱、芦苇和香蒲的生长有一定的抑制作用,植物单元对工业废水中有机物的净化效果明显好于无植物单元,且植物生长越好,人工湿地内水体中的COD净化效果越好。混合植物单元对高含盐量工业废水中COD的总去除量约为无植物单元的4倍,证明植物的存在可以增强湿地单元内土壤微生物对有机物的去除能力。

Petroleum and fine chemical industrial wastewater,treated by biochemical process with high salinity,low nutrient content and high COD concentration can be further treated by constructed wetland for reuse. A pilot-scale surface-flow constructed wetland was set up to treat the biochemically treated wastewater from petroleum and fine chemical industry,which is characterized by its high salinity,insufficient nutrients and high COD. The growth of three plants and the COD removal comparison between mixed-planted unit and non-planted unit were investigated: onion,reeds and cattails. The effect of plant growth on microbial biomass and COD removal in high-salinity industrial wastewater was also studied. The aim of this study is to determine the indirect ecological effects of wetland plants on COD removal. The results indicate that the growth of the three investigated plants was inhabited by high-salinity industrial wastewater. The COD removal in the mixed-planted unit was better than that in non-planted unit. The better the wetland plants grow,the higher the COD removal rate. The COD removal capacity in the mixed-planted unit was approximately 4 times higher than that in non-planted unit. Therefore,the organism removal capacity of microbes in soil can be improved by plants in constructed wetland.