Synergistic Effects of High Rate Algal Pond and Submerged Macrophyte Pond on Constructed Wetland for Water Purification

This study was to assess the synergistic effects of high rate algal pond (HRAP) and submerged macrophyte pond (SMP) on constructed wetland (CW) for water purification. The results showed that algae debris and algae-macrophyte photosynthesis could promote the carbon and oxygen level while surplus algae were effectively inhibited by Vallisneria natans, thus facilitating nitrificationdenitrification and organic degradation of subsequent CW in HRAP-SMP-CW hybrid system. Water purification performance in hybrid system was significantly better than that in single HRAP, SMP and CW reactor. The extension of hydraulic retention time in hybrid system was conducive to higher-quality effluent. 89.4 +/- 2.5% algae biomass, 93.2 +/- 1.4% NH4-N, 90.0 +/- 1.4% TN, 99.9 +/- 0.1% TP and 92.4 +/- 2.0% COD could be reduced in hybrid system under 5d-HRT. The study demonstrated that the novel integration of pond-wetland hybrid system could be a cost-effective wastewater treatment technology.

Automated summary

The study showed that the integration of HRAP and SMP in CW had synergistic effects on water purification. The performance of the hybrid system was significantly better than individual reactors. Extending the hydraulic retention time in the hybrid system improved effluent quality, demonstrating the cost-effectiveness of this wastewater treatment technology.