Performance Of Wastewater Treatment By Solar Micro Aeration Combined With Artificial Wetland

In this study, anaerobic/aerobic biofilm and vertical flow constructed wetland(VFCW) were combined to treat domestic wastewater with high concentration, in which modification of zeolite media in VFCW, as well as, the removal of pollutants in the combined system were investigated. Influencing factors for natural zeolite adsorption of ammonia was firstly studied, and several modifying methods, including roasting, acid, alkali, and salt leaching, were thereby evaluated during media modification. And the results showed that theory monolayer adsorption capacity of zeolite could be increased by 16%, upon the coupled modification of roasting and salt leaching. The adsorption process accorded with Langmuir and Freundlich isotherm model, which accords with the pseudo two order kinetics adsorption behavior.Performance of wastewater treatment in the combined system was also examined. Under the conditions of high influent concentration, i.e., COD=582.57 mg/L, NH4+-N=159.89 mg/L, TN=186.54 mg/L, TP=14.49 mg/L, the biofilm reactor could remove a majority of COD and ammonia, whereas the removal of TN and TP was inefficient. The light intensity of solar influenced the power of aeration equipment and air supplement. Higher DO level of 5 mg/L could be remained only during the period of 11:00-16:00, and it thus resulted in better degradation of pollutants in the biofilm reactor.Two VFCWs with different wetland plants of Canna and yellow flag were run respectively, and the results showed that Canna wetland had more satisfying efficiencies in viewpoint of COD and NH4+-N removal, namely 22.6% vs. 15.6% and 14.24% vs. 3.7%. Therefore, stable performance of the domestic wastewater with high concentration could be achieved by adopting the combined system, and the average removal efficiencies of COD, NH4+-N, TN and TP were maintained around 79.8%, 75.2%, 62.4% and 57.1%, respectively.