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Photocatalytic Inactivation of Pathogenic Viruses Using Metal Oxide and Carbon-Based Nanoparticles
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Lan Ching Sim, Wei Qing Wee, Shien Yoong Siow, Kah Hon Leong, Jit Jang Ng, Pichiah Saravanan
Woo et al. (2012) designed a microwave-irradiation-assisted filtration system to inactivate viral aerosols, which can reach a high inactivation efficiency of around 5-log. Xia et al. (2019) demonstrated the efficacy of nonthermal plasma (NTP) against MS2 virus using a packed bed nonthermal plasma reactor. Approximately 2.3-log virus was reduced in which ~2-log of the MS2 inactivated and ~0.35-log physically removed in the packed bed. Wigginton et al. (2012) used five different disinfectants, such as free chlorine (FC), heat, UV irradiation, singlet oxygen, and chlorine dioxide (ClO2), to inactivate MS2 virus. They found that each treatment method resulted in a unique inactivation mechanism. For example, ClO2 or heat treatments may be suitable for inactivating double-stranded DNA viruses with genome repair mechanisms. UV treatment was more effective for inactivating single-stranded RNA viruses without genome repair mechanisms. Nonthermal plasma (NTP) produces chemically active species, such as atomic oxygen, hydroxyl radicals, and ozone, to remove bioaerosol. However, the production of toxic byproduct, such as CO, O3, NOX and aerosol particles, restricts its application (Yu et al. 2009). Other conventional methods like UV irradiation, thermal treatment, and microwave irradiation are not practical because they require high energy consumption. Therefore, heterogeneous photocatalysis has recently emerged as an alternative technology to the current viral inactivation since the foremost discovery by Sjogren and Sierka (1994).
Biological Applications
Published in Yong Yang, Young I. Cho, Alexander Fridman, Plasma Discharge in Liquid, 2017
Yong Yang, Young I. Cho, Alexander Fridman
The first factor that usually comes to mind when discussing the sterilization of liquid is the thermal effect. Many conventional sterilization methods are based on the use of heat, with a typical treatment time of about 1 h. Note that most nonthermal plasma discharges operate at low temperatures and do not provide thermal sterilization. However, one should keep in mind that even strongly nonequilibrium discharges can be characterized by elevated temperatures in some localized intervals in time or in space. For example, dielectric barrier discharge (DBD) is traditionally considered nonthermal. But, the temperature inside DBD microdischarge channels can reach several hundred degrees, where the thermal effect should be taken into account. Overheating of the microdischarge channels occurs usually due to nonuniformity of electrodes, and the strong contribution of radicals or charged species to sterilization can also be enhanced by even a small temperature increase.
Hydrogen from Natural Gas
Published in Prasenjit Mondal, Ajay K. Dalai, Sustainable Utilization of Natural Resources, 2017
Mumtaj Shah, Prasenjit Mondal, Ameeya Kumar Nayak, Ankur Bordoloi
Nonthermal plasma systems are also referred to as cold plasma systems, which operate under nonequilibrium thermal conditions. An electric discharge, similar to thermal plasmatron, generates the chemically active species, which can catalyze the methane and steam reaction. The use of nonthermal plasmatron offers several advantages over thermal plasmatron such as reduced electric consumption, lower temperature operation (near room temperature), insignificant electrode erosion, and compact reactor design. Application of different types of nonthermal plasma systems have been reported in literature for reforming of natural gas to hydrogen-rich gas such as (1) gliding arc technology, (2) corona discharge, (3) microwave plasma, and (4) dielectric barrier discharge.
Electrohydrodynamic drying: Effects on food quality
Published in Drying Technology, 2021
Conversely, cold or nonthermal plasma is an ionized gas composed of photons, ions, reactive species, and free electrons. It is produced by the application of high electric field through corona discharge, dielectric barrier discharge (DBD), glow discharge, atmospheric pressure plasma jets, or pulsed plasma discharge.[32] CP is traditionally used in the food industry to reduce microbial load,[33] which can be attributed to the antimicrobial effect of ozone, surface etching by reactive species and chemical reactions. The direct application of CP for food treatment caused minor quality changes.[34] Interestingly, pretreatments with CP are reported to improve drying kinetics without adversely affecting food quality.[35–37] In this context, CP produced via EHD is beneficial for food quality and shelf stability.[38] It can be concluded that EHD drying combines the benefits of electrically induced moisture removal and antimicrobial effect of CP.[39] Also, the chemical effect of CP should be accounted for while evaluating the food quality in EHD drying.[40]