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The Future of Solid State Actuators in Micromechatronic Systems
Published in Kenji Uchino, Micro Mechatronics, 2019
As infectious or contagious disease involves some association with terrorist activities, those five are related to each other. In the United States, politicians were attacked with anthrax in 2001. In order to neutralize the biological attack, Pezeshk et al. at Penn State University developed a portable hypochlorous-acid disinfection device using a piezoelectric ultrasonic humidifier.39 Hypochlorous acid is a strong disinfectant with no side effects on humans and would be ideal for disinfecting office and hospital buildings against viruses like SARS and anthrax. Coupled with the atomization of the acidic solution, much higher disinfection effects can be expected. This acid is not sold as a pure solution since it naturally disintegrates after a few hours. We designed a corrosion-resistant electrolytic cell to produce hypochlorous acid from brine. An ultrasonic piezoelectric atomizer was utilized to generate microdroplets of the diluted acid.
Water Treatment Operations
Published in Frank R. Spellman, Handbook of Water and Wastewater Treatment Plant Operations, 2020
Hypochlorous acid (HOCl) is a weak acid—meaning it dissociates slightly into hydrogen and hypochlorite ions—but a strong oxidizing and germicidal agent. Hydrochloric acid (HCl) in the above equation is a strong acid and retains more of the properties of chlorine. HCl tends to lower the pH of the water, especially in swimming pools where the water is recirculated and continually chlorinated. The total hypochlorous acid and hypochlorite ions in water constitute the free available chlorine. Hypochlorites act in a manner similar to HCl when added to water, because hypochloric acid is formed.
Application of ultrafiltration-reverse osmosis system double membrane method in advanced treatment of fluoride in raw water
Published in Binoy K. Saikia, Advances in Applied Chemistry and Industrial Catalysis, 2022
Baoyun Wang, Xilin Dong, Yunlong Guo, Fuqiang Shi, Zhihua Guo, He You, Hongwu Li
In order to control water-borne infectious diseases caused by the presence of carcinogenic microorganisms in water, water plants will perform chlorination and disinfection when treating drinking water. However, while using its disinfection effect, the water plant also needs to control its concentration to prevent excessive content from affecting human health. The national standard requires that the chloride concentration in drinking water shall be controlled within 250mg/L. Through additional experiments, while monitoring the fluoride removal effect of the original treatment process by the double membrane method, the ability of the method to remove chlorides is monitored at the same time. To explore the further application potential of the double membrane method in water plants. Through the comparison of the monitoring results in Figure 5, it is found that the chloride concentration in the water quality remains basically stable after the water plant undergoes the double-membrane method transformation. There are no obvious signs of reduction. The reason may be that the water plant will add liquefied chlorine gas in order to disinfect the raw water. Chlorine reacts with water to generate hypochlorous acid and hydrochloric acid. Hypochlorous acid destroys the active enzymes in microorganisms and kills microorganisms. The remaining hypochlorous acid will naturally decompose to produce oxygen and hydrochloric acid. Eventually, these hydrochloric acid will naturally volatilize during the process of transporting to the water pipe network. Although the membrane system will remove part of the chloride, the chloride generated by adding chlorine has not been completely volatilized. Therefore, the content did not change significantly. It shows that the double membrane method does not affect the chloride treatment capacity of the water plant and ensures the quality stability of the factory water of the water plant.
Application of Pd-Sn modified Ru-Ir electrode for treating high chlorine ammonia-nitrogen wastewater
Published in Environmental Technology, 2022
Zhen-xing Yang, Wen-yu Xie, Fang-fang Ye, De-hao Li
Firstly, the electrode exchanged electrons with water to generate hydroxyl radicals (MOx(·OH)) as adsorbent, which reacted with chloride ions to produce hypochlorite active group (MOx(·OCl)) and chlorine gas, or chloride ions directly exchanged electrons with the electrode to produce chlorine gas. This process is shown in Equations (1)–(5). Thereafter, the generated chlorine gas reacted with water to produce hypochlorous acid. MOx(·OH), MOx(·OCl), chlorine gas, and hypochlorous acid were used to indirectly oxidize ammonia-nitrogen, as shown in Equations (6) and (7). In the present study, the Pd-Sn modified Ru-Ir electrode in saturated sodium chloride solution exhibited good performance of both chlorine-evolution and electrical conductivity, which was conducive to the progress of the chlorine-evolution reaction and promoted the generation of the residual chlorine. Therefore, it can be concluded that the modified Ru-Ir electrode with Pd-Sn was suitable for the application of electro-catalytic oxidation of ammonia-nitrogen with chloride ions as the medium.
Use of ozonation technology to combat viruses and bacteria in aquatic environments: problems and application perspectives for SARS-CoV-2
Published in Environmental Technology, 2023
Letícia Reggiane de Carvalho Costa, Liliana Amaral Féris
Desinfection treatments implemented in water and wastewater treatment plants are generally based on hypochlorous acid (free chlorine), chlorine dioxide and in some more complex cases, ozone or UV radiation [94]. Due to the phylogenetic similarities between SARS-CoV-1 and SARS-CoV-2, the disinfection technologies adopted during the SARS epidemic can also be implemented for the inactivation of SARS-CoV-2 in wastewater [95]. Understanding the deterioration of SARS-CoV-2 during disinfection or removal by other treatment technologies helps to take proper control measures to eliminate the chances of transmission.
Adaptive neuro-fuzzy approach to sodium chlorate cell modeling to predict cell pH for energy-efficient chlorate production
Published in Chemical Engineering Communications, 2021
Sreepriya Sreekumar, Aparna Kallingal, Vinila Mundakkal Lakshmanan
Hypochlorous acid is a weak acid and partially dissociates into hypochlorite ions ( and called active chlorine.