Stormwater runoff pollution control performance of permeable concrete pavement and constructed wetland combined system: toward on-site reuse

Urban waterlogging and the deterioration of receiving water quality caused by stormwater runoff have become increasingly significant problems. Based on the concept of combining grey and green infrastructure, a combined permeable concrete pavement (PCP) and constructed wetland (CW) system has been developed to treat stromwater runoff and enable on-site reuse. The results showed that the removal rate of suspended solids (SS) by PCP ranged from 96.61 to 99.20%; however, the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) concentrations in the effluent did not meet the standards required for rainwater reuse. For the combined PCP-CW system, the removal rates of COD, TN and TP by the CW were 48.45-75.12%, 47.26-53.05%, and 59.04-75.28%, respectively, under different hydraulic loading (HL) rates; thus, the effluent TN concentrations did not consistently meet the reuse standards. Further optimization of aeration in different parts of the CW revealed that aeration in the middle and front sections of the wetland had the most significant effect on pollutant removal, under which the TN concentrations in the effluent met the standard required for reuse. The effluent from the combined PCP-CW system was able to fully meet the stormwater reuse standards under these optimized conditions, and the reuse of urban stormwater runoff can therefore be realized.

Automated summary

Urban waterlogging and poor water quality caused by stormwater runoff are growing problems. A combined permeable concrete pavement and constructed wetland system was developed to treat and reuse stormwater runoff. The system achieved high removal rates for suspended solids, but the effluent did not meet the standards for rainwater reuse in terms of chemical oxygen demand, total nitrogen, and total phosphorus concentrations. Further optimization of aeration in the wetland allowed the system to meet the standards for stormwater reuse.