Bourgeous K N, Darby J L, Tchobanoglous G
Department of Civil and Environmental Engineering, University of California at Davis, 1 Shields Avenue, Davis, CA 95616, USA.
Water Res. 2001 Jan;35(1):77-90. doi: 10.1016/s0043-1354(00)00225-6.
The effects that wastewater quality and mode of operation have on the performance of an asymmetric, hollow fiber, polysulfone, ultrafiltration (UF) membrane with a molecular weight cutoff of 100,000 Daltons were investigated. Performance was assessed through monitoring membrane flux, transmembrane pressure, effluent biochemical oxygen demand, and operational cost of the experimental system while treating filtered secondary, secondary, and filtered primary effluents. Fluxes achieved for filtered secondary (129-173 l/m2 h), secondary (101-158 l/m2 h), and filtered primary (20-41 l/m2 h) effluents were compared to those obtained at three other locations where similar UF systems were operated. A conceptual model of the impact of an insufficient backwash and of operating the UF system at constant flux on membrane performance is presented to explain the differences in fluxes. Employing pre-membrane granular filtration to remove a portion of the problematic particles in secondary effluent prior to UF led to optimal operational conditions. The costs associated with the operation of pre-membrane granular filtration were offset by the increase in production achieved. Although the use of recirculation could increase maintainable flux when treating a concentrated feed (e.g., filtered primary effluent), the associated costs were high. Improved UF performance was found to result from allowing flux to decline naturally, rather than using a constant flux mode of operation. The effluents produced when filtered secondary and secondary effluents were the feeds would be equivalent to an oxidized, coagulated, clarified, and filtered wastewater as per Title 22 California Wastewater Reclamation Criteria.
研究了废水水质和运行模式对截留分子量为100,000道尔顿的不对称中空纤维聚砜超滤（UF）膜性能的影响。在处理过滤后的二级出水、二级出水和过滤后的一级出水时，通过监测膜通量、跨膜压力、出水生化需氧量和实验系统的运行成本来评估性能。将过滤后的二级出水（129 - 173升/平方米·小时）、二级出水（101 - 158升/平方米·小时）和过滤后的一级出水（20 - 41升/平方米·小时）所达到的通量与在其他三个运行类似超滤系统的地点所获得的通量进行了比较。提出了一个关于反冲洗不足和超滤系统在恒定通量下运行对膜性能影响的概念模型，以解释通量差异。在超滤之前采用膜前颗粒过滤去除二级出水中一部分有问题的颗粒，可实现最佳运行条件。膜前颗粒过滤运行相关的成本被产量增加所抵消。尽管在处理浓缩进料（如过滤后的一级出水）时使用再循环可以提高可维持的通量，但相关成本很高。发现允许通量自然下降而非采用恒定通量运行模式可提高超滤性能。当以过滤后的二级出水和二级出水作为进料时产生的出水，根据加利福尼亚州第22号废水回收标准，相当于经过氧化、混凝、澄清和过滤的废水。
