School of Environmental Science & Engineering, Tianjin University, Tianjin 300350, China.
School of Environmental Science & Engineering, Tianjin University, Tianjin 300350, China; Tianjin key Laboratory of Pollution Prevention-Control and Carbon Sink Along Land-Sea Waters, Tianjin 300350, China.
Sci Total Environ. 2024 Dec 1;954:176615. doi: 10.1016/j.scitotenv.2024.176615. Epub 2024 Sep 28.
Microorganisms thriving in drinking water distribution system (DWDS) reduces biological stability of water, causing numerous threats to residents' drinking water safety. Traditional disinfection methods have intrinsic drawbacks, including microbial reactivation and byproduct formation, leading to waterborne diseases. Thus, effective disinfection techniques are required to ensure the microorganism's inactivation and enhance biological stability. Micro-nano bubbles (MNB) provide a promising result to these issues. This study simulates the hydraulic conditions of the tank of DWDS to investigate the enhancement of biological stability in the tank using MNBs with distinct gas sources. The analysis focused on water quality characteristics, biological stability indicators, and microbial community composition. The results showed that the dissolved gas method could generate abundant bubbles with a particle size below 1000 nm, with a concentration exceeding 10/mL in water. The particle size and Zeta potential of bubbles were crucial factors influencing in situ the ·OH generation; hence, the ·OH concentration was highly sensitive to changes in bubble size. In addition, MNBs inhibited the growth of target bacteria in water, degraded organic matter, and improved the biological stability of drinking water, reaching significant degradation rates for biodegradable dissolved organic carbon (42.74 %), assimilable organic carbon (49.49 %), and total bacteria (51.32 %). MNBs directly degraded organic matter in water by ·OH generation in situ, reducing the microbial nutrient source, thereby inhibiting microbial metabolism and activity, which induced optimum disinfection effects on Proteobacteria, Cyanobacteria, and Planctomycetota in water. In particular, the proposed experiment achieved a 100 % disinfection rate for Acinetobacter in Proteobacteria, disrupting metabolic intermediate functions with the microbial community after MNB treatment. Therefore, this study has demonstrated the potential of MNBs to enhance the biological stability of drinking water, improve water quality, and ensure residents' water health, providing valuable technical support for drinking water safety.
微生物在饮用水分配系统（DWDS）中茁壮成长，降低了水的生物稳定性，对居民的饮用水安全造成了诸多威胁。传统的消毒方法存在固有缺陷，包括微生物复活和副产物形成，导致水传播疾病。因此，需要有效的消毒技术来确保微生物的失活和增强生物稳定性。微纳米气泡（MNB）为解决这些问题提供了有希望的结果。本研究模拟 DWDS 水箱的水力条件，使用具有不同气源的 MNB 来研究水箱中生物稳定性的增强。分析侧重于水质特征、生物稳定性指标和微生物群落组成。结果表明，溶解气体法可以产生大量的气泡，粒径小于 1000nm，水中浓度超过 10/mL。气泡的粒径和 Zeta 电位是影响原位·OH 生成的关键因素；因此，·OH 浓度对气泡尺寸的变化非常敏感。此外，MNB 抑制了水中目标细菌的生长，降解了有机物，提高了饮用水的生物稳定性，对可生物降解溶解有机碳（42.74%）、可同化有机碳（49.49%）和总细菌（51.32%）的降解率达到显著水平。MNB 通过原位产生·OH 直接降解水中有机物，减少微生物营养源，从而抑制微生物代谢和活性，对水中的变形菌门、蓝藻门和浮霉菌门产生最佳消毒效果。特别是，所提出的实验在 MNB 处理后，通过破坏微生物群落的代谢中间功能，实现了对变形菌门中不动杆菌属的 100%消毒率。因此，本研究表明 MNB 具有增强饮用水生物稳定性、改善水质和保障居民用水健康的潜力，为饮用水安全提供了有价值的技术支持。
