硝化是氯化饮用水系统的主要挑战,导致不希望的消毒剂残留损失。因此,异养细菌生长增加,对水质产生不利影响,引起味道,气味,和健康问题。在配水系统(WDS)的易感区域定期监测各种水质参数有助于在较早阶段检测硝化,并有足够的时间采取纠正措施来控制它。监测WDS中硝化的策略需要进行各种微生物测试或评估受微生物活性影响的替代参数。此外,微生物衰变因子(Fm)被水务公司用来监测硝化状态。相比之下,在WDS中管理硝化的方法包括控制影响一氯胺衰变率和铵底物可用性的各种因素,可以抑制硝化。然而,其中一些控制策略可能会提高受管制的消毒副产品水平,这可能是一个潜在的健康问题。在本文中,严格审查了WDS中监测和控制硝化的各种策略。主要发现是:(I)一些方法的适用性需要使用真实的WDS进一步验证,由于最初的研究是在实验室或中试系统上进行的;(ii)没有发现将替代参数与硝化细菌浓度相关的链接/公式,这可能会提高硝化监测性能;(iii)需要改进的方法/监测工具来检测早期的硝化;(iv)需要进一步的研究来了解可溶性微生物产品对替代参数变化的影响。根据目前的审查,我们建议使用许多这些方法的成功结果通常是特定地点的,因此,在考虑经济和可持续性方面时,水务公司应根据其常规经验做出决定。
Nitrification is a major challenge in chloraminated drinking water systems, resulting in undesirable loss of disinfectant residual. Consequently, heterotrophic bacteria growth is increased, which adversely affects the water quality, causing taste, odour, and health issues. Regular monitoring of various water quality parameters at susceptible areas of the water distribution system (WDS) helps to detect nitrification at an earlier stage and allows sufficient time to take corrective actions to control it. Strategies to monitor nitrification in a WDS require conducting various microbiological tests or assessing surrogate parameters that are affected by microbiological activities. Additionally, microbial decay factor (Fm) is used by water utilities to monitor the status of nitrification. In contrast, approaches to manage nitrification in a WDS include controlling various factors that affect
monochloramine decay rate and ammonium substrate availability, and that can inhibit nitrification. However, some of these control strategies may increase the regulated disinfection-by-products level, which may be a potential health concern. In this paper, various strategies to monitor and control nitrification in a WDS are critically examined. The key findings are: (i) the applicability of some methods require further validation using real WDS, as the original studies were conducted on laboratory or pilot systems; (ii) there is no linkage/formula found to relate the surrogate parameters to the concentration of nitrifying bacteria, which possibly improve nitrification monitoring performance; (iii) improved methods/monitoring tools are required to detect nitrification at an earlier stage; (iv) further studies are required to understand the effect of soluble microbial products on the change of surrogate parameters. Based on the current
review, we recommend that the successful outcome using many of these methods is often site-specific, hence, water utilities should decide based on their regular experiences when considering economic and sustainability aspects.