Department of Civil & Environmental Engineering, Lamar University, Beaumont, TX, 77710, USA.
Center for Advances in Water & Air Quality, Lamar University, Beaumont, TX, 77710, USA.
Environ Sci Pollut Res Int. 2021 Jul;28(27):36573-36584. doi: 10.1007/s11356-021-13193-1. Epub 2021 Mar 11.
Although electrochemical disinfection has been shown to be an effective approach to inactivate bacteria in saline water, the effects of process parameters and reactor design for its application in low-salinity water have not been well understood. In this study, factorial experiments were performed to investigate the direct and confounded effects of applied current (5-20 mA), contact time (2.5-20 min), anode surface area (185-370 cm), and chloride concentration (50-400 mg L) on the disinfection efficiency in fresh water and the secondary effluent of municipal wastewater. An electrochemical disinfection reactor cell with an internal volume of 75 cm was designed and fabricated. Residence time distribution analysis showed that the internal mixing of the reactor is similar to that of a dispersed plug-flow reactor. All studied process parameters showed significant effect on the kill efficiency, with the applied current and contact time having the most dominant effect. Although the effect of chloride concentration, which is responsible for electrochemical production of free chlorine in water, is statistically significant, it is not as prominent as those reported for high salinity water. A synergistic effect between chloride concentration and anode surface area was identified, leading to high kill efficiency (99.9%, 3 log kill) at low current density (0.0135 mA cm). Response surface modeling results suggested that a scaled-up disinfection reactor can be designed using large anode surface area with long contact time for high chloride water (400 mg L) or high current density with short contact time for low chloride water (50 mg L). The power requirement of a portable system treating 37.85 m day (10,000 gpd) of municipal wastewater was estimated to be 1.9 to 8.3 kW to achieve a 3 log kill, depending on the reactor design.
虽然电化学消毒已被证明是一种有效方法，可以灭活盐水中的细菌，但对于其在低盐度水中的应用，过程参数和反应器设计的影响尚未得到很好的理解。在这项研究中，进行了析因实验，以研究施加电流（5-20 mA）、接触时间（2.5-20 分钟）、阳极表面积（185-370 cm）和氯离子浓度（50-400 mg L）对淡水和城市废水二级出水消毒效率的直接和混杂影响。设计并制造了一个内部体积为 75 cm 的电化学消毒反应器单元。停留时间分布分析表明，反应器的内部混合类似于分散的推流反应器。所有研究的过程参数对杀菌效率都有显著影响，施加电流和接触时间的影响最大。虽然氯离子浓度（负责电化学产生水中游离氯）的影响在统计学上是显著的，但它不如在高盐度水中的影响显著。氯离子浓度和阳极表面积之间存在协同作用，导致在低电流密度（0.0135 mA cm）下实现高杀菌效率（99.9%，3 对数杀灭）。响应面建模结果表明，可以使用大阳极表面积和长接触时间设计放大的消毒反应器，用于高氯离子水（400 mg L），或使用高电流密度和短接触时间设计用于低氯离子水（50 mg L）。估计处理 37.85 m 天（10,000 gpd）城市废水的便携式系统的功率需求为 1.9 至 8.3 kW，具体取决于反应器设计，以实现 3 对数杀灭。
