基于铁碳内电解的物化—生物耦合深度脱氮

Advanced Nitrogen Removal by a Physicochemical and Biological Coupling Process Based on Iron-Carbon Internal Electrolysis

以自制复合铁碳填料为载体,建立物化-生物耦合脱氮体系,考察了HRT、DO含量、进水pH对低C/N(COD/ρ(TN)=1.5:1)污水脱氮的影响,并通定量了物化作用对脱氮的贡献率。结果表明,在耦合体系中,NH_4^+-N通过氨氧化菌和硝化菌的作用生成NO_3^--N和NO_2^--N,NO_3^--N和NO_2^--N进入生物膜内部,自养反硝化菌以载体原电池反应所产生的[Fe^(2+)]、[H]为电子供体实现反硝化脱氮,其适宜运行条件为:HRT为4.0 h,DO的质量浓度(2.0±0.1)mg/L,进水pH为7.0±0.1,此时污水COD、NH_4^+-N、NO_3^--N、TN去除率分别可达94.6%~97.3%、82.1%~83.6%、92.1%~94.7%、89.3%~92.5%。适宜的HRT低于其它同步硝化反硝化脱氮过程。反应器内反硝化所需电子37.9%由载体物化反应供给,消除了传统生物脱氮过程对有机碳源的依赖,源缩短了脱氮所需停留时间。故该耦合体系可实现低C/N污水的高效深度脱氮。

A physicochemical and biological coupling process was developed with the composite iron-carbon based biological carrier and applied in a plug-flow pilot scale cylindrical reactor for treatment of wastewater with COD/ρ（TN）=1.5：1.The result indicated that the NO_3^--N and NO_2^--N were reduced in to N_2 by the autotrophic denitrifying bacteria using[Fe^（2＋）]and[H]as electron donor.The suitable HRT,DO,and initial pH of 4.0 h,（2.0±0.1） mg/L and7.0±0.1 were gained,with the COD,ammonia,nitrate,and TN were degraded removal of 94.6%-97.3%,82.1%-83.6%,92.1%-94.7% and 89.3%-92.5%,respectively.37.9% of the electrons that were used in denitrifying were supplied by the physicochemical reaction in the carrier,which eliminated dependence of denitrification on the organic carbon source.Hence,the physicochemical and biological coupling process appears to be a viable method to advanced low C/N wastewater treatment.