高盐工业废水人工湿地处理中植物的筛选

通过人工湿地中试实验,考察了芦苇、睡莲、水葱、狭叶香蒲和宽叶香蒲水生植物单元对经生化处理的石油和精细化工工业区的工业废水中盐含量较高、氮磷营养盐含量较低和化学需氧量(COD)含量较高的废水中污染物的去除情况,研究了在植物不同生长阶段系统中COD的去除同盐度之间的关系,探讨了盐度差异对植物生长状况的影响,为确定人工湿地适合的进水盐度,达到有效去除高含盐量工业废水中有机污染物提供依据。结果表明,芦苇、睡莲和狭叶香蒲3种植物单元内高含盐量工业废水中污染物的净化效果较水葱和宽叶香蒲单元的净化效果好:前3种植物单元内COD、生化需氧量(BOD)和总磷(TP)的去除率大约在38%、55%和62%左右,而水葱和宽叶香蒲2种植物单元内COD、BOD和TP的去除率大约在30%、36%和52%左右;系统中各个单元内总氮(TN)去除率都在85%以上。在植物的不同生长阶段,人工湿地系统中氯离子浓度与COD浓度之间的相关性存在差异:植物生长初期,系统中氯离子浓度与系统中COD浓度之间无显著相关性,而在植物生长旺期和末期,两者则成正相关关系。因此,需根据植物的生长阶段调整人工湿地的进水盐度。

Purification efficiency of different aquatic macrophytes wetland in high-salinity industrial wastewater

Petroleum and fine chemical industrial wastewater,treated by biochemical process with a high salinity,low nutrient content and high COD concentration can be further treated by constructed wetland for reuse.The aim of this study is to determine appropriate feed water salinity of constructed wetland,providing criteria for effective removal of organic pollutants in high-salinity wastewater.Through experiment on pilot-scaled constructed wetlands,effect of organic removals in this wastewater by different vegetations systems such as Phragmites communis,Scirpus tabernaemontani,Nymphaea tetragona ect were investigated,respectively.The relationship between COD removal and salinity of wastewater under the different plants growth was studied;and the impact of various salinity of waste water on species growth was discussed.The results indicate that,pollutant removal effeciancies by Phragmites communis,Nymphaea tetragona and Typha angustifolia system are better than that of Scirpus tabernaemontani and Typha latifolia system: the removal rate of COD,BOD and TP by the first three plants systems is about 38%,55% and 62%,while the removal rate of COD,BOD and TP for the rest two plants systems is about 30%,36% and 52% respectively;removal rate of TN by all the sysytems is above 85%.The relationship between chloride concentration and COD concentration of constructed wetland are various at different stages of plants growth.There is no significant correlation between them at the initial stage of plants growth,but positive correlation is shown in the following stages of plants growth.Therefore,salinity of the inlet should be adjusted according to plant growth stage in the constructed wetland.