British Geological Survey, Keyworth, Nottinghamshire NG12 5GG, UK; UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK.
British Geological Survey, Wallingford OX10 8BB, UK.
Sci Total Environ. 2021 Jan 1;750:141284. doi: 10.1016/j.scitotenv.2020.141284. Epub 2020 Jul 27.
Regular monitoring of drinking water quality is vital to identify contamination of potable water supplies. Testing for microbial contamination is important to prevent transmission of waterborne disease, but establishing and maintaining a water quality monitoring programme requires sustained labour, consumables and resources. In low resource settings such as developing countries, this can prove difficult, but measuring microbial contamination is listed as a requirement of reaching the UN's Sustainable Development Goal 6 for water and sanitation. A nine-month water quality monitoring programme was conducted in rural Malawi to assess the suitability of tryptophan-like fluorescence (TLF), an emerging method for rapidly detecting microbial contamination, as a drinking water quality monitoring tool. TLF data was compared with thermotolerant coliforms (TTCs, E. coli) and inorganic hydrochemical parameters. A large (n = 235) temporal dataset was collected from five groundwater drinking water sources, with samples collected once or twice weekly depending on the season. The results show that TLF can indicate a broader contamination risk but is not as sensitive to short term variability when compared to other faecal indicators. This is likely due to a broad association of TLF with elevated DOC concentrations from a range of different sources. Elevated TLF may indicate preferential conditions for the persistence of TTCs and/or E. coli, but not necessarily a public health risk from microbial contamination. TLF is therefore a more precautionary risk indicator than microbial culturing techniques and could prove useful as a high-level screening tool for initial risk assessment. For widespread use of TLF to be successful, standardisation of TLF values associated with different levels of risk is required, however, this study highlights the difficulties of equating TLF thresholds to TTCs or E. coli data because of the influence of DOC/HLF on the TLF signal.
定期监测饮用水水质对于识别饮用水供应的污染至关重要。检测微生物污染对于防止水传播疾病的传播很重要，但建立和维护水质监测计划需要持续的劳动力、消耗品和资源。在发展中国家等资源匮乏的环境中，这可能证明是困难的，但测量微生物污染被列为实现联合国可持续发展目标 6 关于水和卫生的要求。在马拉维农村进行了为期九个月的水质监测计划，以评估色氨酸样荧光（TLF）作为饮用水质量监测工具的适用性，TLF 是一种新兴的快速检测微生物污染的方法。将 TLF 数据与耐热大肠菌群（TTCs、大肠杆菌）和无机水化学参数进行了比较。从五个地下水饮用水源收集了大量（n=235）时间数据集，根据季节每周采集一次或两次样本。结果表明，与其他粪便指标相比，TLF 可以指示更广泛的污染风险，但对短期变化的敏感性较低。这可能是由于 TLF 与来自各种不同来源的升高的 DOC 浓度广泛相关。升高的 TLF 可能表明 TTCs 和/或大肠杆菌持续存在的有利条件，但不一定存在微生物污染的公共卫生风险。因此，TLF 是一种比微生物培养技术更具预防性的风险指标，可作为初步风险评估的高级筛选工具。然而，要成功广泛使用 TLF，需要标准化与不同风险水平相关的 TLF 值，但本研究强调了由于 DOC/HLF 对 TLF 信号的影响，将 TLF 阈值等同于 TTCs 或大肠杆菌数据的困难。
