State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.
State Key Laboratory of Hydro-Science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.
J Hazard Mater. 2018 Jan 15;342:446-453. doi: 10.1016/j.jhazmat.2017.08.030. Epub 2017 Aug 18.
Ozone is widely used for water treatment because of its strong oxidation ability. However, the efficiency of ozone in groundwater remediation is limited because of its relatively low solubility and rapid decomposition in the aqueous phase. Methods for increasing the stability of ozone within the subsurface are drawing increasing attention. Micro-nano-bubbles (MNBs), with diameters ranging from tens of nanometres to tens of micrometres, present rapid mass transfer rates, persist for a relatively long time in water, and transport with groundwater flow, which significantly improve gas concentration and provide a continuous gas supply. Therefore, MNBs show a considerable potential for application in groundwater remediation. In this study, the characteristics of ozone MNBs were examined, including their size distribution, bubble quantity, and zeta potential. The mass transfer rate of ozone MNBs was experimentally investigated. Ozone MNBs were then used to treat organics-contaminated water, and they showed remarkable cleanup efficiency. Column tests were also conducted to study the efficiency of ozone MNBs for organics-contaminated groundwater remediation. Based on the laboratory tests, field monitoring was conducted on a trichloroethylene (TCE)-contaminated site. The results showed that ozone MNBs can greatly improve remediation efficiency and represent an innovative technology for in situ remediation of organics-contaminated groundwater.
臭氧由于其强大的氧化能力而被广泛用于水处理。然而，由于其在水相中的溶解度相对较低且分解迅速，臭氧在地下水修复中的效率受到限制。因此，提高臭氧在地下水中稳定性的方法引起了越来越多的关注。微纳米气泡（MNBs）的直径范围从几十纳米到几十微米，具有快速的传质速率，在水中能够持续较长时间，并且随地下水流动一起运输，这显著提高了气体浓度并提供了连续的气体供应。因此，MNBs 在地下水修复中具有相当大的应用潜力。在本研究中，研究了臭氧 MNBs 的特性，包括其大小分布、气泡数量和 ζ 电位。实验研究了臭氧 MNBs 的传质速率。然后，使用臭氧 MNBs 处理有机物污染的水，结果表明它们具有显著的净化效率。还进行了柱试验以研究臭氧 MNBs 对有机物污染地下水修复的效率。基于实验室测试，对一个三氯乙烯（TCE）污染场地进行了现场监测。结果表明，臭氧 MNBs 可以大大提高修复效率，代表了一种用于原位修复有机物污染地下水的创新技术。
