Department of Civil Engineering, University of New Mexico, 210 University Blvd NE, Albuquerque, NM 87106, USA.
Water Res. 2014 Feb 1;49:53-61. doi: 10.1016/j.watres.2013.11.006. Epub 2013 Nov 21.
The effect of the solids retention time (SRT) in a membrane bioreactor (MBR) on the fouling of the membranes in a subsequent reverse osmosis (RO) process used for wastewater reuse was studied experimentally using a pilot-scale treatment system. The MBR-RO pilot system was fed effluent from the primary clarifiers at a large municipal wastewater treatment plant. The SRT in the MBRs was adjusted to approximately 2, 10, and 20 days in three experiments. The normalized specific flux through the MBR and RO membranes was evaluated along with inorganic and organic constituents in the influent and effluent of each process. Increasing the SRT in the MBR led to an increase in the removal of bulk DOC, protein, and carbohydrates, as has been observed in previous studies. Increasing the SRT led to a decrease in the fouling of the MBR membranes, which is consistent with previous studies. However, the opposite trend was observed for fouling of the RO membranes; increasing the SRT of the MBR resulted in increased fouling of the RO membranes. These results indicate that the constituents that foul MBR membranes are not the same as those that foul RO membranes; to be an RO membrane foulant in a MBR-RO system, the constituents must first pass through the MBR membranes without being retained. Thus, an intermediate value of SRT may be best choice of operating conditions in an MBR when the MBR is followed by RO for wastewater reuse.
采用中试规模处理系统，实验研究了膜生物反应器（MBR）中固体停留时间（SRT）对后续用于废水再利用的反渗透（RO）过程中膜污染的影响。MBR-RO 中试系统以大型城市污水处理厂初沉池出水为进水。在三个实验中，将 MBR 中的 SRT 分别调整至约 2、10 和 20 天。评估了通过 MBR 和 RO 膜的归一化比通量，以及每个过程进水和出水的无机和有机成分。正如以往研究中所观察到的那样，增加 MBR 中的 SRT 导致大量 DOC、蛋白质和碳水化合物的去除率增加。增加 SRT 导致 MBR 膜的污染减少，这与以往的研究一致。然而，RO 膜污染的趋势却相反；增加 MBR 的 SRT 导致 RO 膜的污染增加。这些结果表明，导致 MBR 膜污染的成分与导致 RO 膜污染的成分不同；在 MBR-RO 系统中，要成为 RO 膜的污染物，这些成分必须首先在不被截留的情况下通过 MBR 膜。因此，当 MBR 之后是 RO 用于废水再利用时，MBR 中最佳的操作条件可能是中间值的 SRT。
