Study On High-salt Industrial Wastewater Treatment For Constructed Wetland

Shanghai Chemical Industry Park (SCIP) adhering to the concept of "green economy" and "circular economy". It committed to environmental protection, while developing the economy vigorously, and 22 hectares of constructed wetlands in SCIP is an important manifestation of this work. Because of the bad quality of the treated industrial wastewater, whose salinity is quite high, it is difficult to directly inject this effluent into the wetland. Therefore, we have to select the suitable influent water and salt tolerance plants for the constructed wetland. And an area of approximately 2000m2 pilot wetlands has been established to research wastewater salinity on plants and microbial activity. Wetland system on high-salt waste water purification effect has also been assessed. Depend on the COD concentration of inlet and outlet, a mathematical model has been established to forecast effluent COD concentration. Based on the mathematical model, we can adjust the wastewater salinity of inlet, in order to control the effluent COD concentration.The results show that Typha latifolia, Typha angustifolia, Scirpus tabernaemontani, Phragmites communis and Nymphaea tetragona can grow well in high salinity wastewater. The strongest salt tolerance is Phragmites communis, followed by Typha, then Scirpus tabernaemontani. While the strongest decontamination capability is Phragmites communis, followed by Scirpus tabernaemontani, and then Typha. If influent concentration of chloride ions can be controlled under 3000mg/L, it is good for wetland decontamination capabilities. The kinetic k-C* model has a certain significance on controlling the COD concentration of outlet for surface flow constructed wetland.