硝化液回流比对ABR-MBR工艺反硝化除磷效能的影响

基于ABR工艺与MBR工艺的耦合联动,以低C/N比生活污水为研究对象,构建生物相分离、液相循环和功能联动的ABR-MBR新型组合工艺,以实现稳定、高效、节能的多功能生物除污(去碳-脱氮-除磷)为目标,通过优化水力停留时间(HRT)以获得ABR优质碳源提供与MBR短程硝化实现的最佳组合,并进行了硝化液回流比为100%、200%、300%和400%时对反硝化除磷的影响研究.ABR-MBR耦合工艺在不同条件下的运行研究结果表明,将溶解氧(DO)维持在低浓度(0.3~1.0 mg·L-1)下及HRT维持在较短(HRTMBR=3 h)情况下在MBR中实现了短程硝化,亚硝酸盐积累率达到60%以上;随着硝化液回流比的增大,ABR中反硝化除磷效能先升高后下降,以300%时反硝化除磷效果为最佳,此时亦处于MBR短程硝化阶段,实现了短程反硝化除磷(主要以NO-2作为电子受体的反硝化除磷),且短程反硝化除磷在系统除磷中占据了主导作用.

Effect of NOx--N Recycling Ratio on Denitrifying Phosphorus Removal Efficiency in the ABR-MBR Combined Process

Based on the coupling of the ABR process and the MBR process, a novel combined ABR-MBR process, including biophase separation, liquid circulation, and functional linkage, was developed to achieve simultaneous carbon, nutrient, and phosphorus removal when treating domestic wastewater with low carbon/nitrogen ratio and to obtain the best combination of ABR, providing a quality carbon source, and MBR, achieving shortcut nitrification by optimizing hydraulic retention time (HRT). The influence of NO_x^--N recycling ratio on nitrogen and phosphorus removal was investigated at NO_x^--N recycling ratios of 100%, 200%, 300%, and 400%, respectively. The experimental results under different conditions showed that the efficiency of denitrifying phosphorus removal in the ABR was found to increase with increasing NO_x^--N recycling ratio from 100% to 300% but decreased when the NO_x^--N recycling ratio was 400%. Shortcut nitrification was achieved by controlling the low dissolved oxygen (DO) concentration ranges from 0.3 to 1.0 mg·L^-1 with the short HRT of 3 h in the MBR reactor. The nitrite accumulation ratio was above 60%, when the NO_x^--N recycling ratio was 300%. Meanwhile, shortcut denitrifying phosphorus removal (where NO₂^--N mainly acted as the electron acceptor for denitrifying phosphorus removal) was achieved and played the dominant role in phosphorus removal.