ABSTRACT
ABSTRACT: Aquatic contamination caused by aquaculture has become a major concern in recent years, and the main pollutants are CODMn, Suspended Substance (SS), ammonia nitrogen (NH3-N), Total Nitrogen (TN), and Total Phosphorus (TP). A water recycling system of attapulgite and artificial wetland was constructed to purify polyculture wastewater from crab (Eriocheir sinensis H. Milne-Edwards) and crayfish (Procambarus clarkii) pond breeding, and then the operation effect was also evaluated. Additional constructions were also designed in this system, including Aquaculture Pond (AP), Precipitation System (PS), Ecological Ditch (ED), Adsorption System (AS), Artificial Wetland (AW), water quality testing system (WS), and External Reservoir (ER). Attapulgite clay in AS had an excellent adsorption capacity of TP and NH3-N in synthetic wastewater due to its structure and physicochemical properties. NH3-N and TN concentrations in water decreased significantly in AW. Dissolved Oxygen (DO) in water increased in ED and AW, and the ED has good effects on SS and CODMn removal. The results of the recycling system indicate that it has an excellent performance of relieving aquatic pollution in crab–crayfish polyculture, without any wastewater discharge.
