Study on the Application and Optimization of Domestic Sewage Treatment Demonstration Based on a Novel Biofilter-Constructed Wetland Coupling System
Abstract A novel biofilter-constructed wetland coupling system has been applied more than 160 domestic sewage treatment projects in different cities of Zhejiang province, China. The performance of a randomly selected project (flux rate was 27.0 m3/d) based on the coupling system was evaluated in long-term, and the effluent monitoring by big data analysis showed a relatively stable and good water quality. The effluent concentrations of CODCr, NH4+-N and TP was 37.57 ± 11.17 mg/L, 5.64 ± 1.69 mg/L and 0.82 ± 0.16 mg/L, respectively, which met the first class of "Standards for Discharge of Water Pollutants from Rural Domestic Sewage Treatment Facilities" (DB33/973–2015). The concentrations of effluent TP showed a strong polynomial curve fitting with effluent NH4+-N concentrations (R2 = 0.9329) according to the big data analysis. Besides, the concentrations of effluent CODCr had a strong positive linear correlation with the concentrations of effluent NH4+-N (R2 = 0.9297), which increased with the increase of effluent TP concentrations (R2 = 0.6957). Results also showed C/N had stronger correlation with pH (R2 = 0.6441), while the concentration of effluent NH4+-N and effluent TP had weak correlation with pH (R2 = 0.3348 and R2 = 0.4834, respectively). The findings might have very important guiding significance for the future monitoring methods of water effluent quality of treatment facility and the cost reduction of monitoring management. Moreover, a demonstration and experiments were carried out for a contrast study of the enhanced system (b) and original system (a). The removal efficiency of CODCr, NH4+-N and TP of the enhanced system (b) was 81.33 %, 90.22 %, and 75.44 %, respectively, which increased by 4.33 %, 9.11 % and 13.77 % respectively compared to the original system (a).
