Sulfate radical based advanced oxidation processes have been extensively studied for the degradation of environmental contaminants. Iron-based materials such as ferrous, ferric, ZVI, iron oxides, ...sulfides etc., and various natural iron minerals have been explored for activating persulfate to generate sulfate radicals. In this review, an overview of different iron activated persulfate systems and their application in the removal of organic pollutants and metals in water and soil are summarised. The chemistry behind the activation of persulfate by homogenous and heterogeneous iron-based materials with/without the assistance of electrochemical techniques are also discussed. Besides, the soil decontamination by iron persulfate system and a brief discussion on the ability of the persulfate system to reduce metals presence in wastewater are also summarised. Finally, future research prospects, believed to be useful for all researchers in this field, based on up to date research progress is also given.
•Iron is an effective activator of persulfate.•Homogeneous, heterogeneous and electrochemical activation of persulfate is effective for pollutant degradation.•Iron activated persulfate is effective for water, wastewater and soil decontamination.
Decontamination helps limit environmental transmission of infectious agents. It is required for the safe reuse of contaminated medical, laboratory, and personal protective equipment, and for the safe ...handling of biological samples. Heat treatment is a common decontamination method, notably used for viruses. We show that for liquid specimens (here, solution of SARS-CoV-2 in cell culture medium), the virus inactivation rate under heat treatment at 70°C can vary by almost two orders of magnitude depending on the treatment procedure, from a half-life of 0.86 min (95% credible interval CI 0.09, 1.77) in closed vials in a heat block to 37.04 min (95% CI 12.64, 869.82) in uncovered plates in a dry oven. These findings suggest a critical role of evaporation in virus inactivation via dry heat. Placing samples in open or uncovered containers may dramatically reduce the speed and efficacy of heat treatment for virus inactivation. Given these findings, we reviewed the literature on temperature-dependent coronavirus stability and found that specimen container types, along with whether they are closed, covered, or uncovered, are rarely reported in the scientific literature. Heat-treatment procedures must be fully specified when reporting experimental studies to facilitate result interpretation and reproducibility, and must be carefully considered when developing decontamination guidelines.
Heat is a powerful weapon against most infectious agents. It is widely used for decontamination of medical, laboratory, and personal protective equipment, and for biological samples. There are many methods of heat treatment, and methodological details can affect speed and efficacy of decontamination. We applied four different heat-treatment procedures to liquid specimens containing SARS-CoV-2. Our results show that the container used to store specimens during decontamination can substantially affect inactivation rate; for a given initial level of contamination, decontamination time can vary from a few minutes in closed vials to several hours in uncovered plates. Reviewing the literature, we found that container choices and heat treatment methods are only rarely reported explicitly in methods sections. Our study shows that careful consideration of heat-treatment procedure-in particular the choice of specimen container and whether it is covered-can make results more consistent across studies, improve decontamination practice, and provide insight into the mechanisms of virus inactivation.
Radioactive substances have been widely used in many industrial sectors, e.g. nuclear power station, biomedical engineering, etc. With increasing applications of nuclear technology, more and more ...radioactive wastewater is being generated via different channels, which indeed is posing an emerging challenge and threat to the environment and human health. Given such a situation, this review attempts to offer a holistic view with regard to the state of the art of technology for decontamination of radioactive wastewater as well as shed lights on the challenges forward. Different from reclamation of other types of wastewaters, the most challenging issue in decontamination of radioactive wastewater is the effective stabilization and solidification of soluble radioactive nuclides present in wastewater, which are critical for final disposal. Moreover, the potential risk of human exposure to wastewater radiation needs to be carefully assessed, and this issue should also be taken into consideration in the selection, design and operation of the radioactive wastewater treatment process. These clearly differentiate the treatment principle of radioactive wastewater from those of traditional industrial and municipal wastewaters. Lastly, the challenges from the perspectives of technology development, environmental and human health impacts and possible solutions forward are also elucidated.
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•Current technologies for decontamination of radioactive wastewater were reviewed.•Preconcentration of soluble radionuclides is essential for further solidification.•Solidification efficiency and cost determine process feasibility.•Chemical precipitation with preconcentration and crystallization appears promising.•Human health impact should be addressed in process selection, design and operation.
The presence of diverse pollutants in water has been threating human health and aquatic ecosystems on a global scale. For more than a century, chemical oxidation using strongly oxidizing species was ...one of the most effective technologies to destruct pollutants and to ensure a safe and clean water supply. However, the removal of increasing amount of pollutants with higher structural complexity, especially the emerging micropollutants with trace concentrations in the complicated water matrix, requires excessive dosage of oxidant and/or energy input, resulting in a low cost-effectiveness and possible secondary pollution. Consequently, it is of practical significance but scientifically challenging to achieve selective oxidation of pollutants of interest for water decontamination. Currently, there are a variety of examples concerning selective oxidation of pollutants in aqueous systems. However, a systematic understanding of the relationship between the origin of selectivity and its applicable water treatment scenarios, as well as the rational design of catalyst for selective catalytic oxidation, is still lacking. In this critical review, we summarize the state-of-the-art selective oxidation strategies in water decontamination and probe the origins of selectivity, that is, the selectivity resulting from the reactivity of either oxidants or target pollutants, the selectivity arising from the accessibility of pollutants to oxidants via adsorption and size exclusion, as well as the selectivity due to the interfacial electron transfer process and enzymatic oxidation. Finally, the challenges and perspectives are briefly outlined to stimulate future discussion and interest on selective oxidation for water decontamination, particularly toward application in real scenarios.
Fresh fruits and vegetables are an essential part of the world populations' diet, contributing essential vitamins and minerals, and they are often eaten raw or minimally processed. Fruits and ...vegetables grown using conventional agricultural methods are at risk from microbiological contamination and foodborne illness relating to the consumption of produce is widely reported throughout the world, as illustrated by recent figures from the USA (at least 713 produce related outbreaks between 1990 and 2005) and UK (88 outbreaks between 1996 and 2006). Better understanding of produce decontamination is essential to support industry in assuring the safety of fruit and vegetable products, thus contributing to consumer health protection.
The purpose of this study was to establish the current state of knowledge on industrial produce decontamination techniques and to identify and prioritise research gaps regarding practical and effective mechanisms to reduce microbial loading of produce with particular reference to industrially cut, washed and prepared fresh produce. Using suitable keywords, a literature review was executed using academic databases and industry sources to identify current literature on different decontamination technologies. Efficacy of approaches was compared to that of chlorine washing, the most common decontamination method used by the fresh produce industry.
Findings indicate that the identified technologies had varying efficacy of microbiological reduction when compared to chlorine, and the reductions achievable across a range of methods are limited, giving rise to food safety concerns. In addition, the results demonstrate that there has been limited consideration given to several key factors, namely industrial application of the technology approaches, organoleptic acceptability of the product, whether the microbiological reduction could be sustained throughout the life of the product and consumer acceptability of the technology. This preliminary study has highlighted concerns about the efficacy of existing produce decontamination techniques and identified research gaps regarding efficacy and industrial application of new decontamination technologies.
► The paper investigates current literature on fresh produce decontamination methods. ► Microbiological reduction is evaluated for various decontamination technologies. ► Different technologies have varying efficacy on microbiological reduction. ► Highlights a need for practical alternatives to chlorine washing to be found. ► Suggests further work on industrial use, organoleptic and consumer acceptability.
In response to consumer preferences for high quality foods that are as close as possible to fresh products, athermal technologies are being developed to obtain products with high levels of ...organoleptic and nutritional quality but free of any health risks. Pulsed light is a novel technology that rapidly inactivates pathogenic and food spoilage microorganisms. It appears to constitute a good alternative or a complement to conventional thermal or chemical decontamination processes. This food preservation method involves the use of intense, short-duration pulses of broad-spectrum light. The germicidal effect appears to be due to both photochemical and photothermal effects. Several high intensity flashes of broad spectrum light pulsed per second can inactivate microbes rapidly and effectively. However, the efficacy of pulsed light may be limited by its low degree of penetration, as microorganisms are only inactivated on the surface of foods or in transparent media such as water. Examples of applications to foods are presented, including microbial inactivation and effects on food matrices.
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