Activated carbon block (ACB)-based point-of-use (PoU) drinking water filters are widely used to remove residual disinfectant, heavy metals, and disinfection by-products (DBPs) from household tap water. The filters are not designed to remove bacteria, which can grow in the filter. Based on previous research, we hypothesized that more biofilm would form in PoU filters due to the presence of chlorinated phenolic DBPs, resulting in higher bacterial concentrations in filtered water. Therefore, studies were conducted by operating a manifold system with three sets of ACB PoU filters that received chloraminated tap water spiked with (50 and 100 ng L⁻¹ added) and without (0 ng L⁻¹ added) pentachlorophenol (PCP) as a surrogate chlorinated phenolic DBP. After processing 85% of the manufacturer's recommended water volume, effluent heterotrophic plate counts plateaued at levels up to 100 times greater than influent counts. The upstream filter fabric developed a significant biofilm that lightened with increasing PCP concentration; however, the overall biofilm mass was not different between treatments. Influent, effluent, and fabric samples had distinct bacterial community structures, and the structure of effluent communities was more similar to that of fabric communities than that of influent communities. The bacterial community structure changed across the filter primarily due to the filter environment itself, while PCP effects were subtle yet significant. The relative abundance of Mycobacterium increased within fabric biofilms when PCP was added, and the absolute abundance was estimated to increase in the effluent relative to the influent. In conclusion, ACB PoU filters significantly alter the bacterial abundance and composition of drinking water.

中文翻译：

---

带有或不带有氯化苯酚消毒副产物的活性炭封闭式使用点（PoU）过滤器的微生物定殖

基于活性炭块（ACB）的使用点（PoU）饮用水过滤器被广泛用于从家庭自来水中去除残留的消毒剂，重金属和消毒副产品（DBP）。过滤器不能去除细菌，细菌可以在过滤器中生长。根据先前的研究，我们假设由于氯化酚DBP的存在，在PoU过滤器中会形成更多的生物膜，从而导致过滤水中细菌浓度更高。因此，通过使用三套ACB PoU过滤器操作歧管系统进行了研究，这些过滤器接收了加有（50和100 ng L ^-1）和不加（0 ng L ^-1的）加氯的自来水。添加）五氯苯酚（PCP）作为氯化氯酚DBP的替代物。在处理了制造商建议的水量的85％之后，流出的异养板数稳定在最高至流入水数100倍的水平。上游滤布形成了重要的生物膜，随着PCP浓度的增加而变亮。但是，不同处理之间的总生物膜质量没有差异。进水，出水和织物样品具有不同的细菌群落结构，并且出水群落的结构与织物群落的结构比进水群落的结构更相似。细菌群落结构在整个过滤器中发生变化的主要原因是过滤器环境本身，而PCP的作用却微妙而显着。分枝杆菌的相对丰度当添加五氯苯酚时，在织物生物膜内的碳含量会增加，并且相对于进水，废水中的绝对丰度估计会增加。总之，ACB PoU过滤器可显着改变饮用水中细菌的丰度和组成。