响应曲面法优化Anammox-MBR工艺及膜表征

Optimization of Anammox-MBR Process by Response Surface Methodology and Membrane Characterization

针对膜生物反应器(MBR)的厌氧氨氧化(Anammox)工艺常面临反应参数难以调控、污泥菌种难以富集等问题,基于Box-Behnken响应曲面法对Anammox-MBR影响因素进行了研究,并模拟得到总氮去除率的二次回归方程。结果表明:在最佳总氮去除条件(温度为36℃、HRT为10.01 h、无机碳源浓度为0.90 mg/L)下,响应曲面优化后的实测总氮去除率(88.98%)与响应曲面拟合所得模型的预测值(89.29%)基本吻合,该模型可用于优化Anammox-MBR对总氮的去除效能。经响应曲面优化后,PVDF中空纤维膜的热力学稳定性下降,活化能降低;膜丝表面官能团发生了变化,增加了醛羰基、羧酸羰基、酯羰基和酮羰基等基团;中空纤维膜表面在调控优化过程中附着污泥、微生物等物质而导致粗糙度增加,总体上有向膜污染发展的趋势。

Anammox in the membrane bioreactor(MBR) often faces problems such as difficulty in regulating reaction parameters and enrichment of functional species.Influence factors of Anammox-MBR were explored by using Box-Behnken response surface methodology,and a quadratic regression equation for predicting total nitrogen removal efficiency was obtained.Under the optimal conditions of total nitrogen removal(temperature of 36 ℃,HRT of 10.01 h and inorganic carbon source concentration of0.90 mg/L),the measured total nitrogen removal efficiency(88.98%) after response surface optimization was basically consistent with the predicted value(89.29%) simulated by the model fitted by response surface methodology,indicating that the model could be used to optimize the removal efficiency of total nitrogen by the Anammox-MBR.After the optimization by response surface methodology,both the thermodynamic stability and activation energy of the PVDF hollow fiber membrane decreased.The functional groups on the surface of the membrane changed,in which aldehyde carbonyl group,carboxylic acid carbonyl group,ester carbonyl group and the ketone carbonyl group appeared.The attachment of sludge,microorganisms and other substances on the surface of the PVDF membrane in the process of adjustment and optimization led to the increase of roughness and an overall profile towards membrane fouling.