组合湿地应用于池塘养殖尾水处理的比较研究OA

"Pond+Constructed Wetland"is an effective technology model for aquaculture wastewater treat-ment.Three sets of wetlands with different process combinations were combined with ponds to create three re-circulating aquaculture systems,which have been in operation for several years.With the designed daily water treatment volume set at 15%of the pond water capacity,we conducted a comparative study on the purification and reuse effects of three different wetland combinations:"horizontal subsurface flow+surface flow construc-ted wetland(Combination A)","paddy field+ecological ditch+ecological pond constructed wetland(Combi-nation B)"and"integrated vertical flow constructed wetland(Combination C)".The results showed signifi-cant removal effects on the primary pollutants of pond aquaculture wastewater,such as total suspended solids(TSS),permanganate index(CODMn),total phosphorus(TP)and total nitrogen(TN),with the effluent water quality meeting the current"Requirements for Discharge of Freshwater Pond Aquaculture Water"(SC/T 9101-2007).Combination A had the highest area removal rates for CODMn and TN at 15.54 and 4.63 g/(m2·d),respectively.In contrast,Combination C had the highest area removal rate for TSS and TP,at 141.68 and 0.65 g/(m2·d),respectively.The systems composed of subsurface flow wetlands had lower ratios of the com-bined purification units to pond area,with 9.2%for Combination A and 16.3%for Combination C,compared to 49.3%for the system composed of paddy field wetlands.Regarding construction costs,Combination A was the most expensive,followed by Combination C,with Combination B being the least costly.Therefore,sub-surface wetland systems are more suitable for aquaculture areas with developed economies,land resource short-ages,and high environmental loads,and can also be used as end-of-pipe treatment for aquaculture wastewater.Paddy fields were ideal for the middle and lower reaches of the Yangtze River and southern plain rice-growing areas,providing a good ecological model of"increasing income,saving water,and reducing e-missions"through integrated planting and aquaculture.In practice,the appropriate wetland process combination should be selected based on local conditions,considering both wastewater purification effectiveness and con-struction and operational costs.