The study evaluated the changes in bacterial numbers across a full-scale membrane bioreactor (MBR) blackwater reuse system. Flow cytometry was used to quantify total and intact bacterial concentrations across the treatment train and during distribution of the recycled water. Membrane passage reduced bacterial numbers by up to 5-log units resulting in coliform-free permeate. A 2-log increase in bacterial cell concentration was subsequently observed after the granular activated carbon unit followed by a reduction in intact cells after chlorination, which corresponds to an overall intact bacteria removal of 3.4-log units. In the distribution network, the proportion of intact cells greatly depended on the free chlorine residual, with decreasing residual enabling regrowth. An initial target of 0.5 mg L⁻¹ free chlorine ensured sufficient suppression of intact cells for up to 14 days (setting the time intervals for system flushes at times of low water usage). Bacterial regrowth was only observed when the free chlorine concentration was below 0.34 mg L⁻¹. Such loss of residual chlorine mainly applied to distant points in the distribution network from the blackwater reuse treatment plant (BRTP). Flushing these network points for 5 min did not substantially reduce cell numbers. At points closer to the BRTP, on the other hand, flushing reduced cell numbers by up to 1.5-log units concomitant with a decreasing proportion of intact cells. Intact cell concentrations did not correlate with DOC, total nitrogen, or soluble reactive phosphate, but it was shown that dead biomass could be efficiently converted into new biomass within seven days.

该研究评估了全尺寸膜生物反应器（MBR）黑水回用系统中细菌数量的变化。流式细胞仪用于量化整个处理过程中以及循环水分配过程中细菌的总浓度和完整浓度。膜通过减少了最多5个对数单位的细菌数，从而产生了无大肠菌的渗透物。随后在颗粒状活性炭单元后观察到细菌细胞浓度增加了2个对数，随后氯化后完整细胞减少了，这相当于完​​整细菌去除了3.4个对数单位。在分配网络中，完整细胞的比例很大程度上取决于游离氯的残留量，而残留的残留量会使再生长。初始目标为0.5 mg L^-1游离氯确保长达14天的完整细胞受到充分抑制（设置低用水量时系统冲洗的时间间隔）。仅当游离氯浓度低于0.34 mg L ^-1时才观察到细菌再生。残留氯的这种损失主要应用于黑水回用处理厂（BRTP）的分配网络中的远处。冲洗这些网络点5分钟并没有实质上减少细胞数量。另一方面，在更接近BRTP的点，冲洗会减少细胞数，最多增加1.5个对数单位，同时完整细胞的比例会下降。完整的细胞浓度与DOC，总氮或可溶性反应性磷酸盐无关，但显示死生物质可以在7天内有效转化为新生物质。