APPLICATION STUDY OF SOLID-LIQUID SEPARATION TOWER COUPLED VERTICAL FLOW CONSTRUCTED WETLAND IN POND-CULTIVATED TAILWATER

Although the pond captive model has several practical advantages, such as being ecologically friendly, resource conserving, and economic effective, research on the treatment mode of pond-cultivated tailwater is still relatively insufficient. In order to reduce the pollution load of captive tailwater and improve the environmental quality of cultured water, we systematically investigated the characteristics of contaminant content in pond-cultivated tailwater during the middle period (from August to October) of pond circle cultivation. The study evaluated the treatment capacity of a solid-liquid separation tower and vertical flow constructed wetland unit for pond captive tailwater, and analyzed the effect of the solid-liquid separation tower vertical flow artificial wetland process to purify cultured tailwater bodies. The results showed that after settling for 1h using a solid-liquid separation tower, the average removal rates of TN and TP in pond-cultivated tailwater were 35.05% and 62.85%, respectively. After settling in a combined vertical flow constructed wetland and improving the intermittent aerated constructed wetland by adjusting the influent COD/N, the DO concentration was improved and the average concentrations of \rmNH^+_4 -N、\rmNO^-_2 -N and soluble phosphate (\rmPO^3-_4 -P) in the reused tailwater were 0.45, 0.02 and 0.48 mg/L, and the average TN and TP removal rates reached 68.04% and 81.49%, respectively, recycling or up to the standard discharge of pond-cultivated tailwater in ponds can be achieved.