Design of combined purification process for aquaculture tailwater and return water of farmland
Aquaculture wastewater and return water of farmland are two major sources of non-point source pollution in agriculture.In the study,a combined purification process for aquaculture wastewater and return water of farmland was designed based on a 466 666.7 m2 modern agricultural site.This process included three types of modules:ecological purification ditch,farmland purification,and landscape wetland forest.Of which,the ecological purification ditch aims to utilize small-scale river drainage systems to control the concentration of pollutants such as nitrogen and phosphorus.It consists of ecological collection and pre-treatment ditches,suspended ecological bed ditches,ecological water conveyance corridors,and regulating and stabilizing ecological ditches.Taking into account the water quality characteristics of aquaculture wastewater and return water of farmland,the effluent water quality were set as follows:chemical oxygen demand(COD)≤ 40 mg·L-1,total nitrogen(TN)≤3 mg·L-1,total phosphorus(TP)≤ 0.5 mg·L-1.After one year of tracking and monitoring,the effluent water quality reached the design targets.In addition,except for TN,both COD and TP could meet the Class Ⅲ water quality requirements specified in the Environmental Quality Standards for Surface Water(GB 3838-2002)for eight months.After implementing this engineering project,the agricultural site not only retains its original production function but also incorporates water purification and landscape aesthetics.The design concept and engineering practices of this process can serve as a reference for controlling agricultural non-point source pollution,particularly in the combined purification of aquaculture wastewater and return water of farmland in other rural areas.
aquaculture tail waterreturn water of farmlandnon-point sourcesprocess designwater purification and ecological restoration
万方数据
维普
