基于物化生化耦合的污水深度脱氮除磷新工艺

为了解决常规污水处理技术无法进行完整的硝化反硝化过程,污水厂出水中氨氮、总氮、总磷偏高以及运行成本较高的问题,以某污水厂排水为研究对象,通过物化与生化耦合,构建化学催化生物耦合床(CCBF)脱氮系统,研究CCBF系统对污水厂排水中氨氮、总氮、总磷和COD的去除效能。结果表明：当DO为5.5~6.0 mg·L⁻¹、RT为8 h、C/N为1.5∶1时,CCBF可将${rm{NH}}_4^{+} $-N从48.5 mg·L⁻¹降至4.58 mg·L⁻¹、TN从51.2 mg·L⁻¹降至6.5 mg·L⁻¹、TP从6.6 mg·L⁻¹降至0.48 mg·L⁻¹、COD从78.5 mg·L⁻¹降至33 mg·L⁻¹,去除率分别达到89.5%、85.7%、92.5%和57.9%;污水经处理后,氨氮、总氮、总磷、COD均达到城镇污水处理厂污染物排放标准(GB 18918-2002)一级A排放标准。利用Eckenfelder方程对系统脱氮过程进行模拟,求得${n_{{rm{NH}}_4^ +{text{-}} {rm{N}}}} $=0.314 76,n_TN=0.282 21,${K_{{rm{NH}}_4^ +{text{-}} {rm{N}}}} $=0.128 02,K_TN=0.218 59,与水力负荷为0.000 8~0.007 m³·(m²·min)⁻¹的常规生物处理相比,系统内部生物量充足、活性高,物化与生物耦合强化效果明显。

Mechanism of strengthened deep nitrogen and phosphorus removal from sewage based on physicochemical and biochemical coupling process

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 ${rm{NH}}_4^ + $-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_{{rm{NH}}_4^ + {text{-}} {rm{N}}}} $=0.314 76 and nTN=0.282 21, reactor rate constants of ${K_{{rm{NH}}_4^ + {text{-}}{rm{N}}}} $= 0.128 02 and KTN=0.218 59, were determined with correlation coefficients (R2) of 0.983 3 for the simulation on ${rm{NH}}_4^{+} $-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.