旋转电极耦合膜分离同步浓缩消化污泥技术机制研究

The process of using membrane for simultaneous thickening and digestion of sludge (MSTD) is paid more attention, due to its advantages such as small footprint, high effluent quality and high efficiency of sludge digestion. However, membrane fouling has blocked the further application of MSTD to sludge treatment. Membrane-coupled rotatable electrodes for simultaneous sludge thickening and digestion（MRESTD）is new technology, which not only combines electrophoresis and electrostatic repulsion to control membrane fouling, but also uses electrochemical oxidation and electro-coagulation to improve the digestibility of sludge and the effluent quality. First, on the basis of the preparation and performance evaluation of the charged membrane module and rotatable electrodes, the operation effect and influence factors of MRESTD will be studied by using response surface model. After that, on the basis of floc destruction mechanism, organic matter metabolism and microbial population evolvement rules, the digestion theoretical model of MRESTD will be established. Moreover, compared with the digestion mechanism of MSTD and MRESTD, the differences of digestion mechanism under effect of electric field will be elucidated. Ultimately, the effect of change of sludge properties and membrane foulants under electric field effect on the membrane fouling will be studied by using of statistical model based on theoretical foundation of membrane fouling mathematical model. Furthermore, according to comparative analysis of membrane fouling mechanism of MRESTD and MSTD, the evolution membrane fouling mechanism under effect of electric field will be elaborated. Therefore, the results of this research will provide theoretical guidance and technical support for application of MRESTD.

膜分离同步浓缩好氧消化污泥技术以占地小、出水水质好、污泥消化效率高等优势得到研究者的关注，然而膜污染较严重制约了其运用。旋转电极耦合膜同步浓缩消化污泥技术是一种利用电泳和静电排斥原理控制膜污染，并结合电极氧化和电絮凝作用提高污泥消化性能和出水水质的新型技术。本研究以带电膜组件、旋转电极制备和性能研究为基础，借助响应面模型，对该技术运行效果及影响因素进行深入研究；然后，以污泥絮体破解机理、有机物代谢规律和微生物种群演变规律为理论基础，建立污泥消化理论研究模型，并与普通膜分离同步浓缩消化机理对比，阐明电场作用下污泥消化机理；最后，以电场作用下膜污染理论数学模型为理论基础，结合统计模型研究分析电场作用下污泥性质演变和膜面污染物演变对膜污染变化影响，并与普通膜处理污泥技术污染机理对比，探索电场作用下膜污染演化机制。因此，本研究成果可为新技术的实际运用提供理论指导和技术支撑。

随着污水处理设施建设高速发展，污泥产量不断上升，而污泥中含有的大量有毒有害物质如处理不当极易对环境造成严重污染。基于膜技术在污水处理领域的广泛应用，膜的高效固液分离能力也逐步应用于污泥处理，然而由于膜同步浓缩消化污泥过程中污泥浓度较高膜污染较为严重，阻碍了膜技术的实际应用。本课题是以剩余活性污泥为研究对象，首先考察了膜分离处理技术中膜污染演变机理，同时，研究外加电场作用下剩余活性污泥性质变化，并分析其电场对膜污染的影响，最后探究了旋转电极耦合膜分离处理剩余活性污泥工艺最佳运行参数和运行效果，阐明新技术污泥消化及控制膜污染机制，为我国污泥稳定化处理提供新的思路。.本课题获得以下结论：（1）外加电场有利于提高剩余活性污泥脱水性及溶胞性，提高污泥稳定效果；电压过高会降低导电膜的临界通量，反而加剧膜污染程度；同时，加电会使污泥混合液 pH 逐渐下降导致带负电粒子逐渐减少，而阴极膜会吸引带正电颗粒，颗粒不断在膜面沉积，使膜污染加剧；（2）10 V 电压条件已超过导电微滤膜的临界场强，电场强度过大使污泥混合液中颗粒不断在膜表面聚集，堵塞膜孔，膜污染加剧；随着污泥浓度和电压梯度的升高，导电膜临界通量逐渐下降，膜过滤性能逐渐降低；实验得出的MRESTD 工艺的最佳电压为 1 V，最佳转速为 60 rmp/min；（3）MRESTD 工艺对比MSTD 工艺污泥消解率略高，说明适当的电场可以提高污泥的消化效果。在最佳的电场强度（1V）作用下污泥粘度、EPS 和 SMP 略微下降，说明微弱电场可以促进消化速率，对污泥混合液的性质也有一定影响，电场作用有利于延缓膜污染。