Abstract:In order to explore the feasibility of treating saline wastewater in constructed wetlands, a lab-scale constructed wetland was built to compare the removal effects of several typical pollutants under different salinities (0, 0.5%, 1.0%, 1.5%, 2.0%). The results showed that: 1) The effects of salinity on the growth of Phragmites communis in constructed wetlands showed the characteristics of “low salt promoting” and “high salt inhibiting”. Under 0.5% influent salinity, the reed had the highest plant height (1.22 m) and the maximum basal diameter (0.48 cm); 2) The removal rate of COD in constructed wetlands was generally increased first and then decreased with the increase of salinity. When the salinity was 0.5%, COD removal rate reached a maximum (84.86%). 3) Under 0.5% influent salinity, the removal of nitrogen and phosphorus from the constructed wetland were almost not inhibited by salt; when the influent salinity was higher than 1.0%, the removal of TN, NH4+-N, NO3--N, and TP all decreased significantly (P<0.05) with the increase of salinity. Under 2.0% salinity, the removal of TN, NH4+-N, NO3--N, and TP dropped to 44.40%, 58.89%, 49.23% and 49.49% respectively, compared with 0.0% salinity, decreased by 38.5%, 23.4%, 23.8% and 19.2%, respectively. 4) Under the same influent salinity, different pollutants were inhibited by different salt levels. Nitrogen is more easily inhibited by salt than phosphorus. NH4+-N is more easily inhibited by salt than NO3--N.