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The purpose of this review was to assess the literature regarding the decontamination of resin cement before the luting procedure in order to provide clinicians with a comparative overview of decontamination effects. A total of 19 articles were selected for inclusion in this review. The results indicated that bonding effectiveness is reduced due to residual adhesion inhibitors such as saliva, blood, hemostatic agents, and temporary/provisional cement. Self-etching and self-adhesive systems tend to be more negatively affected by adhesion inhibitors than do etch and rinse systems. Cleaning with an ultrasonic scaler or rotating brush have demonstrated conflicting effects in several studies. Some studies have reported that phosphoric acid has negative effects and recommend mild acid for decontamination. The application of phosphoric acid followed by sodium hypochlorite has been shown to help avoid negative effects. Alumina blasting has been investigated as a mechanical cleaning method in a relatively large number of experiments, most of which have confirmed its effectiveness. An intraoral cleaner containing functional monomers that has become commercially available in recent years is a promising method in clinical practice because it can easily and effectively remove temporary adhesive material. In addition, adhesion inhibitors can be easily removed from resin-coated dentin surfaces. ispartof: JAPANESE DENTAL SCIENCE REVIEW vol:57 pages:147-153 ispartof: location:Netherlands status: published

A critical global issue in the 21st century is water shortage, as well as its pollution with noxious metal ions and organic dyes. To extract these pollutants from wastewater, a variety of traditional methods have been employed but they lack reusability/recyclability, are expensive, environmentally unfriendly, unsafe and the remediation process takes a long time. Therefore, to treat these contaminants, nanotechnology (NT) has recently been granted several leeways in terms of making the desirable nanomaterials (NMs) with high surface-to-volume ratios and special surface functionalities. In particular, fly ash (FA) has stood out as one of the greatest exciting new-found affordable and high efficient materials for water decontamination owing to its high porosity, huge surface area, and exceptional features. Hence, this present review study will attempt to compile data from existing literature on the utilization of FA-based adsorbent for the removal of heavy metals (HMs) and dyes from wastewater. Based on the reviewed publications, Langmuir's isotherm models (LIMs) and Freundlich's isotherm models (FIMs) best described the sorption process thus signalling monolayer and multi-layer sorptions. Pseudo-second-order (PSO) model provided the best appropriate means in elucidating the kinetic process and both exothermic and endothermic processes revealed the nature of the thermodynamic process during sorption. Some recommendations in the form of future prospects on how to advance the capacity of the adsorption and effectiveness of FA on the removal of HMs, dyes and other environmental contaminants using innovative technologies such as the nanofiber technology is also been proposed.

The gamma-ray exposure doses in decontamination operation after a nuclear accident were evaluated with a consideration of various geometrical conditions and specific gamma-ray energies. The calculation domain is organized with three residence types and each form is divided into two kinds of geometrical arrangements. The position-wise air KERMA values were calculated with an assumption of evenly distributed gamma-ray source based on Monte Carlo radiation transport analysis using the MCNP code. The radioactivity is initially set to be unity to be multiplied by the deposition value measured in the actual accident condition. The workforce data set depending on the target object was determined by modifying the Fukushima report. The external exposure doses for decontamination workers were derived from the calculated KERMA values and the workforce analysis. These results can be used to efficiently determine the workforce required by the characteristics of the area and the structure to be decontaminated within the dose limits.

Highlights • N95 masks needed by healthcare workers could be in short supply during a pandemic situation • The study provides information on different sterilizing methods on the filtration efficiency of N95 masks • We recommend plasma sterilization for decontamination of N95 masks during non-availability of supplies. • Since the UV irradiation method showed variations in our trials, we recommend that evaluation of UV decontamination for N95 masks needs to be done on a case-to-case basis., Objectives Due to the surge in the demand for N95 masks during the current pandemic of Covid-19, and considering the situation in countries grappling with acute shortages in N95 masks, we investigated the possibilities of decontamination and reuse. Methods Three N95 masks of different makes (A, B and C), were subjected to 6 decontamination methods, namely UV irradiation, Isopropyl alcohol (IPA) dip, Plasma sterilization ( Sterrad®), Ethylene Oxide (ETO, 3M®), Dry heat sterilization and Moist heat sterilization. The integrity of the N95 masks were assessed by measuring their particle filtering efficiency at particle size range between 0.3 and 0.5 microns. Results All the masks decontaminated with ETO and plasma sterilization retained over 95% particle filtering efficiency. Masks decontaminated using IPA dip and Autoclaving showed a drop and UV irradiation, showed variations in particle size efficiency degradation, post decontamination. Conclusions We recommend plasma sterilization for decontamination of N95 masks in low resource settings. ETO was not recommended due to hazards associated with handling of ethylene oxide, though the filtering efficiency was retained. Since the UV irradiation method showed variations in our results, we recommend that evaluation of UV decontamination for N95 masks needs to be done on a case-to-case basis.

In this paper, from a review of the size distribution of the bubbles during pool scrubbing obtained from experiments by EPRI, we apply the bubble size distributions to analyses on the decontamination factors of pool scrubbing via I-COSTA (In-Containment Source Term Analysis). We perform sensitivity studies of the bubble size on the various mechanisms of deposition of aerosol particles in pool scrubbing. We also perform sensitivity studies on the size distributions of the bubbles depending on the diameters at the nozzle exit, the molecular weights of non-condensable gases in the carrier gases, and the steam fractions of the carrier gases. We then perform analyses of LACE-ESPANA experiments and compare the numerical results to those from SPARC-90 and experimental results in order to show the effect of the bubble size distributions.

Vaporized hydrogen peroxide (VHP) is a highly active disinfectant, and VHP decontamination systems have been widely applied in hospitals, microbiological laboratories, and pharmaceutical industries. However, the decomposition of VHP into non-toxic by-products is essential. Evaluation of the disinfection efficacy of VHP is crucial to ensuring the reliability of VHP disinfection and controlling microbial contamination. In this study, a rapid and sensitive strategy is proposed to evaluate the efficacy of VHP in surface disinfection by detecting the survived and killed bacteria from VHP-exposed biological indicators (BIs). A dual-channel solid-phase cytometer is designed, and fluorescent dyes are used as indicators to automatically and accurately distinguish live cells from dead cells in the mixtures of bacteria. To verify the availability and effectiveness of the laser scanning cytometry, experiments on its application in estimating the efficacy of VHP disinfection practice have been carried out in this study, and its estimation effect compared with that of the traditional plate counting method. Results show that the proposed assay might distinctly identify live or killed cells labeled by green and red fluorescent dyes and examined the disinfection efficacy in 30 min by calculating the bactericidal rate. Compared with the plate counting method, the proposed approach is accurate and practical, with an average detection efficiency of 98.47% ± 1.55%. Moreover, an excellent correlation between the concentrations of B. subtilis var niger (ATCC 9372) measured by the proposed detection system and by the plate counting method is noticed (R2 = 0.9971), indicating that this approach had advantages in the detection of trace microorganisms. To summarize, the proposed strategy appears practical and significant in many fields in which microbial counting and identification are required.

Oil palm agro-industry is a major revenue earner for Malaysia with the country being one of the major producers of crude palm oil (CPO) and oil palm products. Its growth has, however, led to massive water consumption and high generation of highly polluting palm oil mill effluent (POME). The inadequacies of ponding system adopted by most palm oil mills (POMs) for the treatment of POME to alleviate environmental and public health concerns are quite alarming. Fenton advanced oxidation technologies are a current research area providing viable alternatives for POME treatment, recovery and managing high demand for water. Its major setback is the generation of a large amount of unwanted sludge of iron (III) complexes thus increasing the costs of sludge management, treatment, and disposal. The salient and promising features of this technique for industrial applications motivate researchers to find ways to overcome its inherent drawbacks. This brief review aimed at discussing and evaluating the performances of the various Fenton oxidation processes, including homogeneous, heterogeneous, photo-Fenton, electro-Fenton, sono-Fenton etc., for POME treatment. Discussions on the future direction of these Fenton processes points towards the utilization of abundant magnetically separable heterogeneous composites as catalysts with high stability, activity, recyclability, and cost-effectiveness for decontamination of POME and other agro-industrial effluents from recalcitrant organic pollutants. The low deployment of such composite catalyst coupled with scarce literature on POME treatment in this regard offers a vast opportunity for research exploration.

Background The periapical area is healed through disinfection of root canal system and reduction of microbial infection after root canal. Purpose To assess the knowledge of dental practitioners about decontamination during root canal treatment and the techniques used in the government and private sectors of Jeddah, Saudi Arabia. Methods 103 dental practitioners and interns from private and governmental sectors performing root canal treatment were included. To extract information, a questionnaire assessing knowledge and preferred techniques used in decontamination during root canals treatment was distributed. The association of variables was investigated using chi-square tests. Results The findings reflected that 82.5% of subjects used rubber dam for isolation with significantly more practitioner in the governmental (95.2%) as compared to the private sector (27.8%). Chelating agents were used by 13.3% of the practitioners in government sector and 1% practitioners in private sector (1%). The most commonly used irrigant was sodium hypochlorite. Calcium hydroxide was used more frequently in the governmental sector (29.8%) than in the private sector (11.8%), as intracanal medicament. Mechanical irrigation devices were used by 2.4% of practitioners in the governmental sector only. Conclusions There is a significant difference in practicing root canal disinfection techniques among dentists in governmental and private sectors but no difference in degree of knowledge.

Background\ud Decontamination of non-critical objects shared by patients is key in reducing hospital-acquired infections (HAIs), but it is a complex process that needs precise guidance from UK National Health Service (NHS) acute care organizations (ACOs).\ud \ud Aim\ud To review the indications given by NHS ACOs' policies regarding the decontamination of shared non-critical devices.\ud \ud Methods\ud Detailed lists of decontamination protocols for shared non-critical objects were retrieved from cleaning, disinfection and decontamination policies of 35 NHS ACOs. Three parameters were considered for each object: decontamination method, decontamination frequency, and person responsible for decontamination.\ud \ud Findings\ud In total, 1279 decontamination protocols regarding 283 different shared non-critical objects were retrieved. Of these, 689 (54%) did not indicate the person responsible for decontamination, and only 425 (33%) were complete, giving indications for all three parameters analysed. Only 2.5% (32/1279) of decontamination protocols were complete and identical in two policies. In policies where cleaning represented the major decontamination method, chemical disinfection was rarely mentioned and vice versa. General agreement among policies was found for four main decontamination methods (detergent and water, detergent wipes, disinfectant wipes, and use of disposable items), two decontamination frequencies (between events and daily) and two responsible person designations (nurses and domestic staff).\ud \ud Conclusions\ud Decontamination protocol policies for shared non-critical objects had some similarities but did not concur on how each individual object should be decontaminated. The lack of clear indications regarding the person responsible for the decontamination process put at risk the ability of policies to serve as guidance.

The window of vulnerability of a bioagent, may this be communicable or not, is while in the environment, before it enters the host or even adheres to it externally, as potent antimicrobial amenities can be used in such conditions with no or little concern for the host entity. There are many such amenities in use, originating from both the health services and the food industry, which allow massive suppression of microbiota or even sterilization, but the usually indiscriminate effectiveness and widespread use may become counterproductive. Thus the use of amenities allowing targeted application with limited collateral damage and sustainability in resources and effects/side effects, especially in environmental terms and also among the susceptible species, is of special importance. Many innovative and proven amenities may be applied in a targeted manner by genomics informing on the comparative susceptibilities of targets vs background/benign organisms and entities. Thus antimicrobial peptides and chemical or radiological disinfectants are routinely used but may be supplemented occasionally by electromagnetic amenities, sound waves, and other pressure waves or extreme heat, salinity, or acidity and live biological or biochemical agents leading to functional or structural neutralization. The differential susceptibility to all these and possibly other suppressants can be accurately predicted by genomic analysis and postgenomic screening by selecting the appropriate approach and dosage for each individual case upon detection and classification, so as to maximize effectiveness with minimal collateral damage.

The combination of low intensity electric fields and plants, named as electrokinetic-assisted phytoremediation, to carry out the decontamination of polluted soils has been proposed as a more ecological alternative to the addition of chelating agents in order to increase the availability of pollutants. It results from the electrolysis of water, which generates redox and acid/base reactions in the soil, and the transport of charged species throughout the liquid phase of the soil. EK-phytoremediation allows to reduce the time of treatment as compared to that of phytoremediation and may be applied to both metal(loid)s and organic pollutants. In this chapter, the multiple aspects concerning the applicability of EK-phytoremediation, such as the electrochemical processes and the physicochemical changes occurring in the soil, along with the effects of electric current on plant biomass and some practical issues of the technique, have been extensively discussed based in the literature published to date.

Contamination of processed meat products can occur from any of a number of sources. Intervention technologies including thermal, nonthermal, biological, and chemical, when used appropriately, are designed to inactivate and/or inhibit foodborne pathogens to ensure the safety of meat and poultry products. In the past several years, significant advances have been made, both in improving existing intervention tools and in developing novel inactivation technologies specifically to this category of meat products. Particular attention has been focused on the hurdle approach of combining multiple intervention technologies to inactivae pathogens in processed meats.

2-chlorophenols (2-CPs) as a biodegradation-resistant pollutant has serious threats to environment and human health. Photocatalytic hydrodechlorination (PHDC) for removal of halogenated organics in water has attracted more attention, however, low utilization-efficiency of atomic H* limits its application. Here, a platinum-load tungsten phosphide/graphitic carbon nitride photocatalyst (Pt-WP/g-C3N4) with enhanced activity for conversion of 2-CPs to biodegradable phenol is designed via prior density-functional-theory (DFT) simulations. Conversion yield of phenol on Pt-WP/g-C3N4 is 92.0%, which is far higher than that of Pt-g-C3N4 (17.8%). Self-built field among Pt, WP and g-C3N4 induces photo-generated electrons migration to reduce H+, while g-C3N4 acts as a ‘H-atom lagoons’ to store H*. Electron spin-resonance spectroscopy indicates that coupling of WP and Pt-g-C3N4 promotes H* production and utilization. Ab-initio molecular-dynamics simulations show that Pt-W-P interface has a good resistance to deactivation to enhance H* generation. It provides a deep understanding of PHDC mechanism and a feasible way to optimize decontamination on heterojunction photocatalyst.

Although organophosphate (OP) pesticides (e.g., parathion, chlorpyrifos) have revolutionized agriculture leading to a dramatic increase in crop yields they also represent a critical and persistent global pollutant detrimental to both the environment and human health. No environmentally friendly and efficient method to remove such pollutants has yet been brought to market. Here we present an enzyme-based technology that facilitates the efficient conversion of a toxic compound (i.e., the pesticide ethyl-paraoxon) into an essential nutrient (i.e., inorganic phosphate) that supports the growth of crops. The efficiency of the technology relies on the combined action of three OP-degrading metalloenzymes with complementary substrate specificity. The enzymes were immobilised on Ni-NTA coated magnetic nanoparticles (MNPs), which significantly enhanced both their thermal stability (by up to 10 °C) and reactivity (up to three-fold). In a test reaction the half-lives of pesticide degradation and phosphate formation were approximately 2 min and 23 min, respectively. Storage of the enzyme-coated MNPs at 4 °C for up to a year resulted in a less than 10% loss of catalytic efficiency. The modular nature of the technology allows the integration of diverse enzymes with desired catalytic properties and thus provides a simple, reliable and reusable system for the decontamination of polluted environments.

A porous carbon foam (P-CF) with high porosity and large pore volume is developed to offer an efficient scaffold for radionuclides adsorption/decontamination. The three-dimensional (3D) porous structure can be easily formed by carbonization of petroleum pitch. During the heat treatment process, the volatile components from the petroleum pitch create highly interconnected pores without any templates, blowing and foaming agents. In addition, Prussian Blue (PB) nanoparticles are introduced onto the surface of the P-CF by a simple hydrothermal method. By combining the enhanced binding affinity to radionuclides with the increased porosity, the synthesized PB@P-CF exhibits the enhanced adsorption capacity for the Cesium ion (133Cs). This study provides a feasible way to utilize residual oil for preparing functionalized porous carbon-based adsorbents for the removal of radionuclides from aqueous solutions. The superior adsorption behaviors of the PB@P-CF make them promising candidates for radioactive materials adsorption/decontamination.

Lead (Pb) contaminated soils pose serious risks to human health and the environment. One remediation technique that permanently removes Pb is chemical soil washing. This study investigated a modified chemical soil washing technique whereby Pb extraction in citrate solution and recovery of dissolved Pb by reductive precipitation (cementation) were simultaneously carried out in a single reactor by the addition of micro-sized zero-valent iron (mZVI) to decontaminate Pb-contaminated soil from a shooting range. Pb-loaded mZVI were then recovered by magnetic separation. The effects of mZVI dosage, citrate concentration, pH, and hydrodynamics on Pb removal were evaluated. Under acidic pH, Pb removal increased with increasing citrate concentration. The addition of mZVI suppressed Pb removal from 59.6 to 30% in 0.1 M citrate solution, which was attributed to dissolved Fe ions competing for free citrate ions to form soluble Fe-citrate complexes. Increasing the citrate concentration and shaking speed enhanced Pb extraction from the soil and subsequent recovery via cementation onto mZVI. Pb removal and recovery onto mZVI of up to 99.0% were achieved at citrate concentration of 0.7 M, pH of 5, and shaking speed of 165 strokes/min. The addition of mZVI during chemical soil washing in citrate solution not only extracted and recovered Pb from the contaminated soil but also eliminated the need to wash soil residues obtained after treatment because the bulk of dissolved Pb was sequestered from the solution.

Advanced investigations on the use of graphene based nanomaterials have highlighted the capacity of these materials for wastewater treatment. Research on this topic revealed the efficiency of the nanocomposite synthetized by graphene oxide functionalized with polyethyleneimine (GO-PEI) to adsorb mercury (Hg) from contaminated seawater. However, information on the environmental risks associated with these approaches are still lacking. The focus of this study was to evaluate the effects of Hg in contaminated seawater and seawater remediated by GO-PEI, using the species Ruditapes philippinarum, maintained at two different warming scenarios: control (17 °C) and increased (22 °C) temperatures. The results obtained showed that organisms exposed to non-contaminated and remediated seawaters at control temperature presented similar biological patterns, with no considerable differences expressed in terms of biochemical and histopathological alterations. Moreover, the present findings revealed increased toxicological effects in clams under remediated seawater at 22 °C in comparison to those subjected to the equivalent treatment at 17 °C. These results confirm the capability of GO-PEI to adsorb Hg from water with no noticeable toxic effects, although temperature could alter the responses of mussels to remediated seawater. These materials seem to be a promise eco-friendly approach to remediate wastewater, with low toxicity evidenced by remediated seawater and high regenerative capacity of this nanomaterial, keeping its high removal performance after successive sorption-desorption cycles.

A UVC photo-Fenton advanced oxidation process (AOP) was studied to develop a process for the decomposition of oxalic acid waste generated in the chemical decontamination of nuclear power plants. The oxalate decomposition behavior was investigated by using a UVC photo-Fenton reactor system with a recirculation tank. The effects of the three operational variables―UVC irradiation, H2O2 and Fenton reagent―on the oxalate decomposition behavior were experimentally studied, and the behavior of the decomposition product, CO2, was observed. UVC irradiation of oxalate resulted in vigorous CO2 bubbling, and the irradiation dose was thought to be a rate-determining variable. Based on the above results, the oxalate decomposition kinetics were investigated from the viewpoint of radical formation, propagation, and termination reactions. The proposed UVC irradiation density model, expressed by the first-order reaction of oxalate with the same amount of H2O2 consumption, satisfactorily predicted the oxalate decomposition behavior, irrespective of the circulate rate in the reactor system within the experimental range. Keywords: AOP, UVC photo-Fenton, Chemical decontamination waste, Oxalic acid

Radioactive dust will accumulate in the vacuum vessel (VV) of ITER after plasma operations. Consequently, the ITER Blanket Remote Handling System (BRHS) will be deployed into the VV to stably handle the blanket modules 1.5 m long, weighing up to 4.5 ton with high positioning accuracy. The BRHS itself must also undergo regular hands-on decontamination and maintenance in the Hot Cell Facility (HCF). However, the workers will be exposed to any activated dust that remains on BRHS component surfaces after remote decontamination. Past studies estimated the contaminated surface area of the BRHS, however, in this study, decontamination tests were performed and the dose rate to maintenance workers was calculated using the Monte Carlo N–Particle Transport Code (MCNP5). Decontamination tests were performed by using multiple test pieces of varying surface roughness made from SUS329J4L and two different types of brushes (nylon and SUS304) to simulate decontamination of the BRHS surface. Tungsten dust was pressed on the test pieces to simulate the loading by the rollers. After the test pieces were brushed the surface of each test piece was observed by using both optical and scanning electron microscopes. Dust was reduced by approximately 99% in all cases where the SUS304 brush was used regardless of surface roughness. The decontamination rate was used to estimate how much dust will be able to be cleaned from the BRHS surface. This paper describes the optimal decontamination tools with respect to the BRHS surface conditions to calculate and hopefully reduce the dose rate to maintenance workers so as to optimize the BRHS maintenance plan in the HCF.

Summary Background There has been an increasing demand for more sanitary bidet seats in many healthcare settings because of concerns regarding potential contamination of the spray nozzles of warm-water bidet toilet seats. This contamination is thought to possibly serve as a reservoir for horizontal transmission of drug-resistant bacteria. Aim This study was performed to determine the optimal Pseudomonas aeruginosa decontamination conditions and verify the effectiveness of these decontamination conditions. Methods An in vitro test of rinsing with neutral electrolysed water was performed using seven strains of P. aeruginosa. The decontamination effect of the neutral electrolysed water was verified by a field test involving an analysis of the number of bacteria isolated from samples collected from the spray nozzles and the sprayed water from 10 toilet seats at the internal medicine ward of Juntendo University Hospital. Findings The in vitro test results showed that the decontamination effect of neutral electrolysed water tended to be higher with higher free chlorine concentrations in the nozzle-cleaning water and shorter intervals of rinsing. The field test involving the hospital ward toilets showed that routine physical cleaning was satisfactorily effective. Conclusion The study results suggest that the risk of horizontal transmission of drug-resistant bacteria via the use of bidet toilet seats in hospitals can be reduced by general cleaning and appropriate control of the free chlorine concentration in the nozzle-cleaning water.

Highlights • Intensified reprocessing of graphite based on dissolution of yttrium. • Understanding into effect of operating conditions on process efficiency. • Effect of adding oxidant, H2O2, to the leachant acid on the decontamination rate. • Weight gain of the graphite substrate due to oxidation, despite surface erosion due to cavitation. • Kinetic study for dissolution of yttrium from graphite of different densities (and pore size distribution)., Yttria coated graphite crucibles are widely used to handle molten refractory and radioactive metals like uranium and plutonium. However, the coated layer suffers damages like cracking and peeling off owing to thermal cycles. As a result, removal of the yttria layer from the graphite surface is essential to ensure reuse of the crucible and minimization of radioactive waste. The present work investigates intensified dissolution of yttria from the coated graphite samples using ultrasound as a non-destructive decontamination technique to recycle the graphite substrate. The optimum conditions established for maximum dissolution were 8 M as acid strength, frequency of 30 kHz, temperature of 45 °C and power density of 8 W cm−2 that resulted in maximum dissolution of 52% in 30 min. Use of an oxidant H2O2 to the acid, did not yield any improvement in the dissolution kinetics, instead, increased oxidation of the graphite substrate was observed, leading to the anomalous weight gain of the graphite substrate despite surface erosion. Effect of ultrasound on the dissolution was pronounced, with almost a threefold increase compared to dissolution performed under silent conditions. Rates of dissolution of yttria from the substrate of different densities and pore size distribution were also studied. The dissolution was slowest from graphite of density 1.82 g cm−3 as the pore size distribution was conducive to accommodate the yttria particles. The dissolution in nitric acid followed ash layer diffusion controlled kinetics. The study has demonstrated the efficacy of application of ultrasound for accelerated decontamination of graphite substrates.

Summary Background Hydrogen peroxide and ozone have been used as chemical decontamination agents for N95 masks during supply shortages. If left behind on the masks the residues of both chemicals are representing a potential health hazard by skin contact and respiratory exposure. Aim Characterization of hydrogen peroxide and ozone residues on mask surfaces after chemical decontamination. Methods Various N95 masks were decontaminated using two commercial systems employing either aerosol spray or vaporization of hydrogen peroxide in the presence of ozone. Following the decontamination, the masks were aired out to eliminate moisture and potential chemical residues. The residual hydrogen peroxide and ozone were monitored in the gas phase above the mask surface, and hydrogen peroxide residue directly on mask surfaces using a colorimetric assay. Findings After decontamination, hydrogen peroxide and ozone were detectable in the gas phase in the vicinity of masks even after five hours (h) of aeration. Hydrogen peroxide was also detected on all studied masks, and levels up to 56 mg per mask were observed after 0.5 h of aeration. All residues gradually decreased with aeration, likely due to decomposition and vaporization. Conclusion Hydrogen peroxide and ozone were present on N95 masks after decontamination. With appropriate aeration, the gaseous residue levels in the vicinity of the masks decreased to permissible levels as defined by the U.S. Occupational Safety and Health Administration. The reliable assays to monitor these residues are crucial to ensure the safety of the mask users.

While the annual European demand for polyolefins is 25 million tonnes, only 3 million tonnes of recycled polyolefins find their place in the market, despite collecting 15 million tonnes of post-consumer polyolefins every year. Brand owners of care products are showing their interest in using post-consumer recycled plastics for their packaging. However, there is a general concern in using these materials, as recycled polymers can contain unwanted substances that may expose the consumer to health risks or make the packaging unattractive. Accordingly, the presence of these contaminants narrows the market opportunity of recycled plastics to applications with low-quality requirements and in which the product is not in direct contact with the consumer. Though mechanical recycling is the most widespread solution presents limitations in terms of decontamination, as only superficial substances are removed. Thereby, the volatile organic compounds (VOCs) migrated to the polymer matrix remain inside. Consequently, there is a need to find a solution to purify recycled plastics and increase their market share. This study focuses on removing VOCs from post-consumer recycled HDPE through two innovative methods applied for the first time in this field, steam stripping and polyethylene glycol (PEG) extraction. The methodology implemented to analyze the volatile organic compounds in HDPE was HS-SPME-GC/MS. Both methods showed a decrease above 70% in the VOCs content compared to extrusion-degassing. Moreover, these were compared to hot air stripping, a new technology developed at an industrial scale for the removal of VOCs. As a result, steam stripping improved efficiency in reducing the overall VOCs compared to hot air stripping. The PEG extraction method lowered the volatile polar compounds further than using hot air stripping. Additionally, none of these technologies modified the HDPE melting flow index. This work was supported by a grant from the University of Alicante as part of the InnoUA Transfer of Knowledge program and co-financed by Cadel Deinking (Industrial Doctorate).

Widespread application of dyes and disposal of their untreated effluents into water bodies adversely affect the ecosystem due to their complex aromatic structures and persistent nature. The present study aims to utilize the cotton stalks biochar (CSB) and its composite with zinc oxide nanoparticles (CSB/ZnONPs) to evaluate for the decontamination their batch scale potential of Congo red dye from wastewater. The characterization of CSB and CSB/ZnONPs was performed with Fourier-transform infra-red (FTIR) spectroscopy, scanning electron microscopy, energy-dispersive X-ray (EDX) and point of zero charge (PZC) to get insight of their potential for the decontamination of CR. The effects of initial CR concentration (25–500 mg/L), dosage of CSB and CSB/ZnONPs (0.5–2 g/L), solution pH (2–10) and contact time (0–180 min) were evaluated on CR removal at temperature (25 ± 1.5 °C). The results disclosed that CSB/ZnONPs showed excellent adsorption potential (556.6 mg/g) in comparison with CSB (250 mg/g) and most of the other adsorbents previously studies in the literature. The equilibrium experimental data were equally explained with Freundlich and Langmuir isotherm models (R2 > 0.98) while kinetic data demonstrated the best fit with pseudo second order model. The CSB/ZnONPs composite exhibited excellent reusability (89.65%) after five adsorption/desorption cycles for the sequestration of CR from contaminated systems. The present study demonstrated that metallic nanocomposite of CSB (CSB/ZnONPs) is an excellent candidate for the cost effective and environment friendly decontamination of CR from industrial wastewater and is suggested to be considered for the decontamination of other pollutants from the wastewater.

Ecuador is a signatory of the Stockholm Convention on chemical substances and hazardous waste and is responsible for complying with the guidelines for the environmentally adequate disposal of Polychlorinated Biphenyls (PCBs) in the country until 2025. The global management of PCBs begins with the sampling of transformers, analysis of dielectric oil, characterization and final disposal of transformers, oil and PCB material belonging to the electricity sector and private owners. The information on the characterization of PCBs is recorded and stored in a computer system called the National PCB Inventory and Monitoring System (SNIS-PCB), in which, the information of 216,632 transformers must be recorded for the present investigation. In the past 2018, the system registered 90,346 transformers, equivalent to 40% of the inventory, 3,494 of them were contaminated and are owned by electricity companies, and it was estimated that there are 1,063 contaminated transformers from private owners. The objective of the research is to analyze the economic and technical feasibility of the technologies available and allowed in the national regulations for the final disposal of these hazardous wastes. According to the technical characteristics of the technologies, logistical limitations and quantity of PCBs in the country, it has been determined that Dichlorination is a technological option that can be used for the treatment of PCBs, also offering the opportunity of decontamination, reuse of the material, and it is friendly with the environment., Dechlorination; Dielectric oil; Incineration of hazardous waste; PCBs; PCB treatment

The present study aimed to investigate the ability of a microbial consortium to produce biosurfactant in the presence of two carbon sources and also to evaluate the efficiency of the cell-free supernatant cultures to mobilize As from naturally contaminated soil. Pseudomonas and Stenotrophomonas were the main microorganisms in the microbial consortium. The pH, the incubation time, the temperature, and the glucose and glycerol ratios in the culture medium are the main factors influencing biosurfactant production. The lowest surface tension, 30 mN.m−1, and the higher emulsification index, 58%, were achieved at the optimum production conditions (OPC), i.e., pH 9.5, a 2.5 glucose/glycerol ratio, after three days of incubation at 25 °C. The cell-free extracts containing biosurfactants were more efficient in mobilizing As than distilled water, CaCl2 0.1 mol.L−1; saponin, 0.1%; or sodium dodecyl sulfate, 1% during a sequential soil-flushing procedure. The As mobilization using the supernatants containing biosurfactant was sensitive to pH. The use of OPC cell-free supernatant under alkaline conditions leads to the best-obtained results: 24.6% of As removal (678 mg.kg−1) during sequential extractions. The toxicity reduction of the column eluted solution from the first to the seventh cycle evaluated by the germination index (GI) and morphological structures of Allium cepa in the ecotoxicological assessment confirmed the efficiency of the proposed treatment. Allium cepa seeds and seedlings were sensitive in detecting As in soil and eluted solutions with short time responses to the contaminant. Seeds development increased gradually with arsenic removal. The germination index rose from 0 to 55% after soil decontamination through the proposed soil-flushing procedure., Soil flushing; Bioremediation; Pseudomonas; Stenotrophomonas; Allium cepa.

Novel processing methods such as cold atmospheric plasma (CAP) and natural antimicrobials like nisin, are of interest to replace traditional food decontamination approaches as, due to their mild nature, they can maintain desirable food characteristics, i.e., taste, texture, and nutritional content. However, the microbial growth characteristics (planktonic growth/surface colonies) and/or the food structure itself (liquid/solid surface) can impact the inactivation efficacy of these novel processing methods. More specifically, cells grown as colonies on a solid(like) surface experience a completely different growth environment to cells grown planktonically in liquid, and thus could display a different response to novel processing treatments through stress adaptation and/or cross protection mechanisms. The order in which combined treatments are applied could also impact their efficacy, especially if the mechanisms of action are complementary. This work presents a fundamental study on the efficacy of CAP and nisin, alone and combined, as affected by food system structure. More specifically, Listeria innocua was grown planktonically (liquid broth) or on a viscoelastic Xanthan gum gel system (1.5% w/v) and treated with CAP, nisin, or a combination of the two. Both the inactivation system, i.e., liquid versus solid(like) surface and the growth characteristics, i.e., planktonic versus colony growth, were shown to impact the treatment efficacy. The combination of nisin and CAP was more effective than individual treatments, but only when nisin was applied before the CAP treatment. This study provides insight into the environmental stress response/adaptation of L. innocua grown on structured systems in response to natural antimicrobials and novel processing technologies, and is a step towards the faster delivery of these food decontamination methods from the bench to the food industry. ispartof: INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY vol:337 ispartof: location:Netherlands status: published

Both sonolysis and heat-activated persulfate (HAPS) are effective advanced oxidation processes (AOPs) for the destruction of organic pollutants in wastewater. Although ultrasound can activate persulfate at ambient temperature, the synergy between ultrasound and HAPS was poorly investigated, especially when megahertz frequency ultrasound is used. The current chapter focuses on studying the synergism between too high-frequency sonolysis (1.7 MHz, 15 W) and HAPS toward the degradation of organic pollutants taking toluidine blue, a persistent textile dye, as a substrate model. An approach of coupling experimental results to simulation of cavitation bubble dynamics has been made to identify synergistic links between individual mechanisms of AOPs in the sono-hybrid system. It is revealed that in sono-hybrid process, chemical effects of ultrasound, and cavitation (generation of oxidants) are important in both substrate degradation and persulfate activation. A higher flux of bubbles has been predicted to be formed in the sonicating solution, generating a higher concentration of hydroxyl radical, particularly at higher liquid temperature. The synergy between individual processes was not always possible. Another notable observation of our study is that the synergy is strongly dependent on operational conditions. Synergisms were only observed at elevated temperatures, neutral pH, moderate substrate concentration, and low persulfate dosage. Overall, the crucial factor of mechanistic interaction between AOPs, resulting in either positive or negative synergy, needs to be accounted for in design and optimization of wastewater treatment processes using the studied sono-hybrid technique.

In the past half-century, scientists were mostly concerned with polychlorinated compounds (dioxins, polychlorinated biphenyls (PCBs), etc.). But in the last decades, polybrominated compounds [especially polybrominated diphenyl ethers (PBDE) present in various materials as flame retardants] became more and more present in the environment, causing a new set of problems, and subsequently challenges. Therefore researchers focused on PBDE degradation processes, one of them being the microbiological one. However, there are other brominated compounds polluting the environment (e.g., hexabromocyclododecane, tetrabromobisphenol A, etc.) that suffer similar or different fates during various biota processes (photodegradation, phytoremediation, or microbiological decontamination). We are making a short literature screening of these naturally occurring processes destined to remove such an alternative threat.

Photocatalytic methods for hydrogen generation and organic pollutant degradation can be considered as economic, and environment-friendly techniques. Transition metal oxides are most commonly used in photo-assisted processes and exhibit enhanced photocatalytic response in hydrogen generation and hazardous contaminant degradation. Various pollutants can be utilized as sacrificial agents according to the available literature. Instead of performing the processes separately, our intention in this chapter is to review various aspects of simultaneous hydrogen generation and wastewater purification. Thus two significant areas of concern, namely the future energy crisis and wastewater purification can be solved with reduced operating cost and time. Coupled photocatalysis for enhanced hydrogen evolution and efficient pollutant decontamination is drawing the attention of researchers worldwide.

Due to high toxicity, heavy metal ions in water pose great risk to the biological system. Therefore decontamination of water polluted by heavy metal ions attracts significant interest of researchers. Adsorption by solid adsorbents has been widely used technique for removal of heavy metal ions from water. Solid wastes generated from industry or anthropogenic activities, and biomass, have been utilized as adsorbents but these wastes modified by nanomaterials have shown improvement in their performance. Therefore, modification of wastes by nanomaterials to form composites and application of those composite materials as adsorbent for removal of heavy metal ions is a potential approach for decontamination of water. Further, this is a twin strategy for reuse of waste and decontamination of water. This paper provides an account of recent advances in applications of composites prepared from modification of wastes by nanomaterials. This covers two types of wastes; (i) Industrial/anthropogenic waste, (ii) biomass waste. The component derived from waste, its role in the formation of the composite and the role it is playing in adsorption of heavy metal ions have been discussed along with role of the nanoparticle component in the composite. The mechanisms of adsorption, regeneration and reuse of composites have also been discussed. This review may pave the way for the design of new composites by modifying wastes for decontamination of heavy metal ions from water.

Along with water scarcity and the new risks related to climate change, pollution is a major issue affecting this vital resource globally. To face the challenge of treating large volumes of pollutants-loaded municipal wastewaters and industrial effluents, researchers have been investigating the application of different biological, physical, and (electro)chemical water treatment technologies. In this context, the application of adsorption for the removal of toxic or undesirable compounds from (waste)water is widely recognized as a versatile decontamination procedure, which is able to deal with a wide range of pollutants under various process configurations and operating conditions. In this chapter, relevant and recent research investigations conducted in North African countries (Libya, Tunisia, and Morocco) are presented and discussed, including diverse sorbents, adsorption systems, and targeted pollutants. Overall the main objective of this chapter is to showcase the current situation and prospects for the production and utilization of conventional and advanced sorbents for water depollution in North Africa.

Residues of analgesics compounds are generated daily polluting the environment including drinking water. Currently, analgesics are considered emerging pollutants of high impact due to their toxic effect on aquatic animals. Different methods have been tested that allow the decontamination of water of these compounds including adsorption, which has a high effectiveness and low cost. However, the performance of the process depends on the type of adsorbent, its physicochemical properties, as well as the characteristics of the adsorbate and the solution. This text compiles the theoretical aspects applied to the adsorption of drugs from aqueous solution on activated carbon, one of the most-used adsorbents in water treatment plants. Additionally, the main results published in the literature on this subject are included, focusing on three important pollutants: paracetamol and diclofenac. According to the literature for the analgesics analyzed in this review, the most-used activated carbons were made from lignocellulosic materials and commercial adsorbents. Other options are activated carbons made from waste as polyethylen. The surface areas of adsorbents used for adsorption are between 184 and 2794 m2 g−1, the maximum adsorption capacity reported in the literature evaluated for acetaminophen is 2794 mg g−1 and for diclofenac 1801 mg g−1. Not all studies report thermodynamic data, however the values found for the change in Gibbs adsorption energy are similar for both analgesics, and is around −25 KJ mol−1.

A challenging task for the 21st century is the cleaning up environmental contaminants using ecofriendly, economical, adoptable, and sustainable technologies. Organophosphorus (OP) compounds are mostly disseminated as agricultural pesticides and plasticizers which has led to environmental accumulation, water and soil toxicity, and they are involved in many poisoning cases every year around the globe. Therefore OP residues are in top of the list for environmental bioremediation. Thus an effective and safe detoxicant therapy is needed. In the bioremediation method, several cyanobacteria, fungi, bacteria, and their enzymes with the potential to degrade OP compounds use OP as an energy source; they have been isolated and efficaciously used for environmental bioremediation in different parts of globe. Nanotechnology is a rapidly growing field of study due to its efficient mechanisms, cost-effectiveness, and environment-friendly approach in comparison to other existing treatments for the bioremediation of environmental contaminants. It makes use of several nanomaterials for the removal of pollutants from soil and groundwater through adsorption, photocatalysis, and encapsulation mode of actions.

Heavy metal (HM) pollution in soil is becoming one of the hot areas of research. Apart from natural sources, a number of anthropogenic activities have contributed a lot toward HMs and metalloids contaminations in the soil. Some of the anthropogenic activities responsible for HMs contaminations are disposal of high metal wastes, land application of fertilizers, rapidly expanding industrial areas, wastewater irrigation, sewage sludge, spillage of petrochemicals. Some of the HMs contaminating the soil are arsenic (As), cadmium (Cd), lead (Pb), copper (Cu), chromium (Cr), zinc (Zn), nickel (Ni), and mercury (Hg). These HMs are harmful to humans, animals, plants, and the environment. Therefore decontamination of HMs and metalloids is essential. Physical, chemical, and biological methods separately or in combination are being used for the removal of HMs. However, in recent years nanomaterials (NMs) are being used for the decontamination of HM ions from soil. In this chapter details of the use of NMs for decontamination have been discussed.

Phenol and its derivatives are most noxious pollutants originated from several industrial operations such as coke and coal production, petrochemical, pulp and paper production, pharmaceutical plants, etc. Phenolic compounds cause many health issues due to their carcinogenic, mutagenic, and teratogenic properties. In the present scenario, existing conventional treatment methods are not efficient and economic for treatment of phenolic wastewater. Hence, there is an urgent need for decontamination of these toxic pollutants from the environment. Being an economical and ecofriendly technology, bioremediation can be a viable alternative to the conventional treatments for efficient removal of toxic pollutants from wastewater and to protect the ecosystem. Therefore, in this perspective, this chapter provides holistic approach on fundamental and enthusiastic utilization of advanced bioremediation techniques for sustainable treatment of phenolic wastewater. In addition to that this section describes about overview of phenolic compounds, factors affecting bioremediation process and types of microorganisms used for bioremediation of phenolic compounds.

Ibuprofen mineralization by Sphingopyxis granuli RW412 was characterized molecularly and the strain assayed to remediate ibuprofen from different artificially polluted media.The high global consumption of ibuprofen and its limited elimination by wastewater treatment plants (WWTPs), has led to the contamination of aquatic systems by this common analgesic and its metabolites. The potentially negative environmental and public health effects of this emerging contaminant have raised concerns, driving the demand for treatment technologies. The implementation of bacteria which mineralize organic contaminants in biopurification systems used to decontaminate water or directly in processes in WWTPs, is a cheap and sustainable means for complete elimination before release into the environment. In this work, an ibuprofen-mineralizing bacterial strain isolated from sediments of the River Elbe was characterized and assayed to remediate different ibuprofen-polluted media. Strain RW412, which was identified as Sphingopyxis granuli, has a 4.48 Mb genome which includes plasmid sequences which harbor the ipf genes that encode the first steps of ibuprofen mineralization. Here, we confirm that these genes encode enzymes which initiate CoA ligation to ibuprofen, followed by aromatic ring activation by a dioxygenase and retroaldol cleavage to unequivocally produce 4-isobutylcatechol and propionyl-CoA which then undergo further degradation. In liquid mineral salts medium, the strain eliminated more than 2 mM ibuprofen within 74 h with a generation time of 16 h. Upon inoculation into biopurification systems, it eliminated repeated doses of ibuprofen within a few days. Furthermore, in these systems the presence of RW412 avoided the accumulation of ibuprofen metabolites. In ibuprofen-spiked effluent from a municipal WWTP, ibuprofen removal by this strain was 7 times faster than by the indigenous microbiota. These results suggest that this strain can persist and remain active under environmentally relevant conditions, and may be a useful innovation to eliminate this emerging contaminant from urban wastewater treatment systems., This study was supported by the Spanish Ministerio de Economía y Competitividad and the Agencia Estatal de Investigación (AEI) (projects CTM 2013-44271-R and CTM 2017-86504-R), and by co-financing from the European Regional Development Fund (ERDF). J.D. Van Hamme is funded with a Natural Sciences and Engineering Research Council of Canada Discovery Grant (RGPIN-2019-06428). We thank Emasagra S.A. for providing effluent samples from a municipal wastewater treatment plant in Granada, Spain. Inés Aguilar-Romero was sponsored by an FPI grant.

Contamination of all segments of environment, that is, water, air, and soil, by various kinds of noxious pollutants has become a global concern because of the destructive effects of pollutants on living beings and the environment. Advancement in science, uncontrolled population growth, rapid industrialization, modern agricultural practices, and increased urbanization over the last few decades has accelerated the problem of environmental pollution manifold. A variety of hazardous pollutants inducing toxic azo dyes, phenols, polycyclic aromatic hydrocarbons, resins, chlorinated biphenyls, pharmaceuticals, heavy metals, acids/alkalis, etc., are being released into the aquatic bodies which have severely deteriorated the aquatic as well as soil ecosystem. The bioremediation technique has been effectively applied for the scavenging of environmental pollutants from soil and water. The different methodologies used in bioremediation process are cost-effective and ecologically sound. The present chapter focuses on the different methods of bioremediation applied for the decontamination of various pollutants. Different techniques of bioremediation have been thoroughly discussed. Various literature regarding the successful attempts for the remediation of organic, inorganic, and heavy metal pollutants has been described in brief.

Wastewater generates a severe environmental problem and represent a threat to water quality when discharged into rivers or lakes leading to the destruction of the affected aquatic ecosystem. Recently, the utilization of natural additives that are biocompatible, biodegradable, renewable with low toxicity is used to retain different pollutants from wastewaters. Many researches highlight the biosorbent ability for the removal of pollutants from wastewaters like heavy metal ions, pesticides, and impurities or textile wastewater dyes. Chitin and chitosan are very interesting polysaccharides because of the presence of multiple reactive functional groups (─OH, ─NH─CO─, and ─NH2) on their chains. They can also be called environmental decontamination functional materials as they can effectively control the development and reproduction of lethal bacteria and also control toxic pollutants. Thus such contaminants must be effectively removed to satisfy tough environmental quality standards. They have different applications because of their advantages including availability, biocompatibility, and biodegradability in food, agriculture and material science. Recently, chitin and chitosan were chosen as adsorbents of heavy metal in wastewater treatment. The most objective of this chapter is to throw light on those adsorbents based on chitin and chitosan that are used in the purification of contaminated water.

Environmental pollution with synthetic polymers (commonly named plastics) nowadays poses serious threats to the environment and human health. Unfortunately, most conventional plastics are highly recalcitrant even under conditions known to be favorable for microbial degradation. Expanding the knowledge regarding opportunities and limitations of the microbial degradability of plastics would largely contribute to the development of adequate decontamination and management strategies for plastic pollution. This chapter provides cultivation approaches to be applied for the characterization of eco-physiologically diverse asco- and basidiomycete fungi with respect to their ability to attack solid and water-soluble synthetic polymers with the help of quinone redox cycling-based Fenton-type reactions, which result in the production of highly reactive hydroxyl radicals. These reactive oxygen species are the strongest oxidants known from biological systems. However, their potential employment by fungi dwelling in diverse habitats as a biodegradation tool to attack synthetic polymers is still insufficiently explored.

Although industrialization has been a boon to our economy and self-sufficiency, yet it accompanies a major drawback of generation of a huge amount of wastes as well as pollutants that accumulate in soil and aquatic systems, eventually contaminating and degrading the ecosystem. Moreover, the ever-increasing human population is making the situation worse. It is therefore a great challenge to manage the rapidly generating enormous amount of organic wastes and the accompanying pollutants. In this respect, biodegradation and decontamination of organic waste by employing microbial inoculants is an eco-friendly and cost-effective sustainable solution. Although the concept of biodegradation and decontamination by microbes is not new, however, it is yet to reach its full application potential. In spite of the promising response of microbial inoculants under laboratory/controlled conditions, a large field-scale application has shown limited efficacy, possibly due to the complex nature and nonsegregation of wastes. Both the waste decomposition through composting and waste decontamination through bioremediation rely on active microbial participation where they perform complex multistep pathways to achieve the final product. Henceforth, improving our perception of the microbial mechanisms and their interactions with organic waste material is the key requirement for harnessing the full potential of microbial technology in maintaining sustainability of the environment. This chapter presents an overview of the current researches on microbial inoculation as a way forward to achieve sustainability in managing overwhelming quantity of organic wastes and to achieve clean environments heavily affected by pollution. Furthermore, the potential of vital processes employed by the microorganisms for sustainable development and environmental management are also discussed, followed by their future prospects.

Availability of decontaminated and clean water is one of the important requisites of the growing population around the globe. However, the fast-growing urbanization and expansion of industrialization along with excessive usage and consumption of chemical products for multiple purposes has increased the contamination level of available waterbodies all over the world. The presence of inorganic and organic pollutants in water bodies causes multiple health hazards. These organic and inorganic pollutants can be removed by biological methods, that is, biodegradation and biotransformation, utilizing various microorganisms (bacteria, algae, and fungi). Studies have shown that during the decontamination process of wastewater using the microbial community, changes occur in the community structure of microbes due to different types of pollutants present in wastewater and the operating parameters of the process. The present review is focused on evaluating the efficacies of various biological methods/technologies used for the removal of organic and inorganic pollutants. Further, research to understand the shift of microbial community profile in different type of wastewater and treatment processes has also been studied.

The contamination of water resources has become a global problem. Advanced oxidation process (AOP) is one of the most applied technology for the degradation and decontamination of wastewater and potable water. The use of powdered nanomaterials in photocatalysis is very common in AOP for the mineralization of organic contaminants in the water systems. However, the AOP has shown excellent results, handling of powdered catalysts, and its separation from the aquatic system poses a challenge to the scientific community. Moreover, the complete recovery of powdered catalysts is a big issue that leads to nano-toxicity. In the last decade, monolith aerogel based semiconductor photocatalysts have been developed and investigated for the decontamination of the wastewater. The aerogels based semiconductor photocatalysts possess excellent features such as high stability, large surface area, high porosity, mechanical strength, easy separation, and visible light active, making it materials for the next generation. In this chapter, the photocatalytic properties of various kinds of aerogels based semiconductor photocatalysts have been summarized. The role of aerogel’s support on the photocatalytic properties also has been discussed.

This chapter addresses important waste management considerations in nuclear decommissioning projects insofar as they affect concrete surfaces. It stems from the information given in Chapters 14 and 15 in that decontamination and dismantling of concrete structures are precursor to and closely linked to waste management. The chapter is based on experience of plants that have been fully decommissioned or are being decommissioned. It offers concurrently: guidance, technological information, and lessons learned. The chapter can then be a valuable reference for radioactive waste professionals and provide interactions between them and those responsible for the planning and execution of decommissioning activities.

Heavy metal contamination is a major land management issue for Australia with long-lasting impacts on human communities and natural environments. Sorbent materials are an important tool to evaluate to determine which solutions are the most effective for target contaminants, particularly in areas where there may be more than one contaminant present. It is also important to consider which materials are the most viable for larger-scale production within a geographic region to reduce the requirement for ongoing sorbent material importation. This chapter evaluates scientific information on 17 different kinds of terrestrial sorbents for decontamination effectiveness of Cd, Cr (III), Cr (IV), Hg, Pb, and Zn in surface soil environments, and considers sorbent origins, general production requirements, and ongoing environmental availability (e.g., major or minor existing waste stream) of sorbent materials in an immediate to longer-term timeframe.

The release of toxic substances and heavy metals into the environment is one of the major issues in our society. At present, there are several new technological approaches to accelerate the cleanup of the contaminated sites. Bioremediation provides several decontamination strategies for contaminated areas, but not found suitable for all. The high concentration chemicals sites were not affected by the bioremediation strategies and are toxic to microbiomes. Hence, the combinatorial approach of the nanomaterials and bioremediation has vast prospective to be effective and sustainable. Due to unique physical and chemical and biochemical characteristics, small-size, high surface area nanoparticles, nanomaterials have gained much interest in different areas of environmental sciences, especially in bioremediation. In recent years, various nanoparticles like metal nanoparticles, biogenic nanoparticles, microbial nano-biomolecules, etc., have emerged as an important branch of nanotechnology and created substantial interest in the use of nanoparticles in various areas. Hence, nanomaterials may be utilized for bioremediation for removal of toxic contaminants, which will be beneficial in time consumption and cost reduction. In this review, we have discussed the several nanomaterials that have been applied so far in the bioremediation of contaminants and toxic materials.

Phytoremediation using lemongrass for decontamination of toxic chromium from contaminated sites, has been explored as a new green approach. Pot experiments were carried out for 60 days in a completely randomized design to investigate the toxicological, physiological, and biochemical changes in lemongrass grown by the applications of chelators and metals ions using a varied percentage of overburden mine and garden soil. The study assessed the bioaccumulation of chromium in plants, essential oil, citral-a and b content of lemongrass plants grown in different concentrations of chromium-rich overburden soil (OBS). The outcomes revealed that the bioaccumulation of chromium in roots and shoots, proline content, level of reactive oxygen species, oil content, and activities of antioxidant enzymes enhance with the increasing concentrations of chromium in the soil, while protein and chlorophyll contents were reduced. The applications of chelators and metals ions in chromium-rich mine soil induced the mobilization of Cr from contaminated soil to the lemongrass plant and thus, increased the biochemical components like citral-a, citral-b, and oil content. The oxidative stress imposed by mine soil chromium has been counteracted by the stress-induced biosynthesis of antioxidant enzymes in lemongrass. The proposed innovative method of phytoremediation using lemongrass as a green tool will contribute knowledge substantially in the future.

The transmission of SARS-CoV-2 virus through aerosols has become an outstanding issue, where plenty of spread aspects are being analyzed. Portable Air Cleaners (PAC) with high-efficiency particulate air (HEPA) filters have been discussed as an adjunctive means for indoor environments coronavirus decontamination. This study evaluates, first, the air and surfaces SARS-COV-2 RNA contamination due to positive patients in households, and second, the efficiency of a PAC with HEPA filter to eliminate virus. A total of 29 air and surface samples were collected inside 9 households, by using an air portable collector with gelatin filters and swabs. SARS-CoV-2 RNA detection was performed using real-time reverse transcription polymerase chain reaction (RT-PCR). Overall, all the air samples collected before using PAC and 75% of swab samples were positive for SARS-CoV-2. After the PAC usage, all samples except one were negative, displaying a 80% device effectiveness. Portable HEPA cleaners usage allowed the removal of SARS CoV-2 and, therefore, they could be recommended for places with inadequate ventilation, considering the limitations and functionality of the device., Graphical abstract Unlabelled Image