基于物化生化耦合的污水深度脱氮除磷新工艺

Currently, the conventional wastewater treatment plants have faced many problems such as incomplete nitrification and denitrification with conventional wastewater treatment technologies, high ammonia nitrogen, total nitrogen and total phosphorus concentrations in the effluent, and high operational cost. In this study, based on the physicochemical and biochemical coupling process, a chemical catalytic bio-coupled filter (CCBF) was constructed to treat the drainage from the wastewater treatment plant. The removal efficiencies of ammonia nitrogen, total nitrogen, total phosphorus and COD in this drainage by CCBF were studied. The results showed at DO of 5.5~6.0 mg•L^-1, HRT of 8 h, C/N ratio of 1.5:1, CCBF could reduce NH₄ ⁺-N from 48.5 mg•L^-1 to 4.58 mg•L^-1, TN from 51.2 mg•L^-1 to 6.5 mg•L^-1, TP from 6.6 mg•L^-1 to 0.48 mg•L^-1, and COD from 78.5 mg•L^-1 to 33 mg•L^-1, respectively, and their removal efficiencies corresponded to 89.5%, 85.7%, 92.5% and 57.9%, respectively. The above four indictors of CCBF effluent could meet the first-class A emission level of national pollutant discharge standard of urban sewage treatment plant (GB18918-2002). The nitrogen removal process in the CCBF system was simulated by Eckenfelder equation. Reaction orders of n_{NH4 ⁺} =0.314 76 and n_TN=0.282 21, reactor rate constants of K _{NH4 ⁺} = 0.128 02 and K_TN=0.218 59, were determined with correlation coefficients (R²) of 0.983 3 for the simulation on NH₄ ⁺-N removal. In comparison with the conventional biological treatment technology at hydraulic loading of 0.000 8~0.007 m³•(m²•min)^-1, the CCBF process contained high content and active biomass, and obvious physicochemical and biochemical coupling effects occurred accordingly.