Decontamination Rate Research Articles

Construction of engineered heterojunction based on CdS and MgO material co-integrated into a flat plane-like graphene for tetracycline decontamination: Ecological hazard assessment and toxicity alleviation

This study encompasses the photocatalytic decomposition activity of an appreciable ternary CdS/MgO/graphene heterostructured composite (denoted as CMG) for the decontamination of recalcitrant tetracycline (TTC) from aqueous environment under LED light illumination. The physicochemical characteristics of the as-prepared catalysts were elucidated utilizing a series of advanced analytical methods including XRD, FTIR, DRS, BET, EIS, TEM, and FESEM. The CMG architectures reveal vigorous photocatalytic performance towards the decontamination of TTC upon exposure to the LED light, the decontamination rate is approximately 5.5, 4 and 3 times higher than neat graphene, MgO and CdS, respectively. Under the optimized conditions (i.e., pH: 7, CMG dosage: 0.5 g. L−1, light intensity: 75 W and TTC content: 30 mg. L−1), the remarkable degradation rate of TTC (98 % in 120 min) was achieved by the CMG/LED system. An inhibitory impact of anions during the photocatalyst process was recorded as follows: Cl− > NO3− > SO42− > PO43−. To provide a comprehensive understanding of the photocatalyst's behavior and shed light on its mechanism, various analytical techniques were utilized including band structure evaluation, EIS, and capture experiments. The active agents trapping experiments evidenced that OH radicals are the predominant decomposing agents participated in the TTC decontamination. Furthermore, the CMG composite exhibited a noticeable performance during six cycling treatment experiments, inducing its remarkable capability for practical applications. The photocatalytic mechanism of the TTC degradation route over the CMG/LED system was unraveled on the basis of the LC-MS analysis. The ECOSAR software calculations forecasted that CMG/LED system could be regarded as an ecologically benign technology to eliminate antibiotic-related hazards to the living individuals and the environment. In extension, the ecological risk assessment of TTC and its intermediates was scrutinized over CMG/LED system for the first time ever, revealing the excellent performance of the target system in diminishing the actual potential ecological risk.

Ambidextrous approach in action: Mg(OMe)2-doped hierarchical porous zirconium MOFs for decontaminating toxic chemical agents in nonbuffered systems

Utilizing a ligand-truncation strategy, a hierarchically porous structure was engineered within MOF-808, designated as HP-MOF-808. Furthermore, Mg(OMe)2 doping yielded HP-MOF-808@Mg(OMe)2, materials with both hierarchical porosity and basic character, for decontamination of two types of toxic chemical agents in nonbuffered solutions. In aqueous solution, the HP-808-2 exhibited decontamination rate constants for dimethyl-4-nitrophenyl phosphate (DMNP) and the nerve agent soman (GD) that were 3.13 and 1.98 times higher than MOF-808, respectively. The decontamination half-lives of HP-808-2@Mg(OMe)2 1:2 for DMNP and GD were further reduced by 13.87 and 36.82 times compared to HP-808-2. The material retains its decontamination efficacy for DMNP even after 60-days exposure in air and maintains structural integrity in solvents devoid of labile hydrogen for at least 24 h. In methanol, HP-808-2@Mg(OMe)2 achieved 100% DMNP decontamination in 25 min, outperforming HP-808-2 at 31.8%, marking it as the fastest DMNP decontamination material in methanol. Theoretical simulations confirmed the experimental findings, clearly demonstrating the energy changes during reactions with various nucleophiles and revealing the degradation process and mechanism of DMNP on the active sites of MOFs. Moreover, these materials rapidly degraded 2-chloroethyl ethyl sulfide (CEES) through hydrolysis, dehydrohalogenation, and heterolytic cleavage, demonstrating great potential for dual decontamination of toxic chemical agents in unbuffered systems.

Removal of Surface Radioactive Uranium(Ⅵ) by Graphene Oxide Modified κ-carrageenan/Konjac Glucomannan Composite Hydrogel

Hydrogel is an effective surface decontamination technology. However, traditional colloid decontaminants face a long curing time and low decontamination rate. A peelable hydrogel coating composed of carrageenan, konjac glucan, and graphene oxide with excellent film-forming performance and decontamination efficiency was explored in this study. The results showed that the graphene oxide was effectively dispersed inside the hydrogel, improving the crosslink density and thermal stability of the hydrogel by forming hydrogen bonds with polysaccharide molecules. The graphene oxide can effectively enhance the decontamination performance of the hydrogel. For stainless steel, ceramic, glass, and rubber surfaces, the decontamination rates of the hydrogel for 30min were 96.95%, 87.6%, 96.27%, and 74.5%, respectively. The decontamination effect was stable to temperature. For cement surfaces, the hydrogel could reach a maximum decontamination rate of 70.68% after 24h. The decontamination efficiency of hydrogel was affected by porosity, surface roughness, and graphene oxide addition. The characterization results of XPS, FT-IR, and SEM/EDS showed that the decontamination process of the composite hydrogel may involve surface wetting, ion diffusion, electrostatic attraction, and physical entanglement.

A Comparative Analysis of Non-Cyanide and Cyanide Gold Leaching Technologies: Lessons Learned from the Failed CLINN GEM Facility and Promising Results of the REVIVE SSMB Project in Itogon, Benguet

This research paper presents a comparative analysis of a non-cyanide gold leaching technologies implemented in the small-scale mining community of Itogon Benguet against a potential gold recovery method with Free Cyanide decontamination and Sodium Cyanide recovery system. The study evaluates the failed CLINN GEM facility and the successful REVIVE SSMB project, focusing on technology readiness and acceptance, operational efficiency, and community engagement. The results demonstrate that the failure of the CLINN GEM facility was attributed to its low community acceptance, high operating costs, and complexity, hindering its practicality and scalability. In contrast, the REVIVE SSMB project achieved exceptional results through an alternative gold ore leaching process using Cyanidation CIP method, driven by strong community engagement, cost-effectiveness, sustainable wastewater/tailings discharge management system and simplified operation approach even for the recovery of gold from complex and low-grade Au ore from the locality. For a viability assessment, a stochastic model for the technology feasibility and project optional valuation under diverse uncertainty consideration for community adoption and expansion presentable to potential investors or for the option right to accept and manage the technology as demonstrated. This research simulated the viability of the REVIVE SSMB approach with a high predictability using Monte Carlo Model through Real Option Analysis; and under the worst-case scenario at 50th percentile (median) 74.53% recovery was achieved. Repeatedly with a similar 50th percentile simulation under an optimized condition with pulp density of 44- 50% and 3kg per ton of activated carbon loading during flotation yielded a gold recovery of 91%. Hence, it is arguably viable, coupling with the 98 to 99% free cyanide decontamination rate and the 55% NaCN recovery successful discharge management system under the REVIVE SSMB 6 months project model.

Rheological and radioactive decontamination properties of ethyl cellulose sols in green solvents at a temperature below 0 °C.

Strippable film decontamination has been considered one of the best prospects for radioactive surface decontamination due to its high decontamination effect and less secondary pollution. However, research into strippable films has until now focused on radioactive decontamination at room temperature. Therefore, it is vital to seek a suitable degradable material for preparing strippable films in removing contaminants in an extremely cold region, as it will face the problem of the freezing of the detergent. Ethyl cellulose (EC) is a kind of degradable biopolymer which is easily dissolved in volatile green organic solvents to form a sol below 0 °C which is advantageous for forming a film. Therefore, it would be the best choice for preparing a strippable film detergent. In this study, EC sols were obtained by placing EC powder into the green solvents anhydrous ethanol and ethyl acetate. The steady and dynamic rheological behavior of EC sols was investigated with a rotary rheometer with the temperature ranging from -10 °C to 0 °C to disclose their spraying performance. Moreover, the radioactive decontamination effect of EC sols and the mechanism were also investigated. The results showed that the EC sols were pseudoplastic fluids which obeyed the Ostwald-de Waele power law below 0 °C. Furthermore, the viscosity of EC sols could be reduced by stirring, which is convenient for large-area spraying during decontamination below 0 °C. At -10 °C, the comprehensive decontamination rates of all plates were over 85%. Therefore, EC sols could be used as a basic material for strippable film decontamination below 0 °C.

Environmentally friendly tea saponin foam detergents costabilized by GO-OH/SiO2 nanoparticles for removing radioactive surface contaminants

Currently, bare silica nanoparticles with low surface activity and weak stabilizing foam ability have restricted applicability in treating surface radioactive pollutants. To address potential issues with SiO2 as a foam stabilizer, a highly efficient foam stabilizer was fabricated by compounding silica with hydroxylated graphene oxide (GO-OH), which was prepared by hydrothermal modification of graphene oxide (GO). Then, an environmentally friendly foam detergent with high stability and high decontamination efficiency was developed using the natural surfactant tea saponin (TAS) as a foaming agent and a composite of silica and GO-OH (GO-OH/SiO2) as a foam stabilizer, which is named tea saponin foam detergent. For different types of surfactants, the structural and morphological characteristics of GO-OH, such as hydrophilic and surface oxygen groups, as well as the synergistic influence of GO-OH with SiO2 on foamability, foam stability, and detergency of the foam detergent, were studied. As a consequence, the TAS foam detergent has good stability with a drain half-life of 68 min. By hydrothermal modification of GO, the contact angle of water on GO-OH in air dropped to 63.2°, which was lower than that (73.0°) on GO. Furthermore, the hydrophilicity of GO-OH increased, and more oxygen-containing groups on GO-OH enhanced its absorption and enrichment of the radionuclide uranium and improved the decontamination rate of the TAS foam detergent. Moreover, when GO-OH was combined with SiO2, the dispersion and stability of SiO2 in the foam detergent improved, and the foam stability of the detergent subsequently further improved. Adding 2 wt% SiO2 and 0.1 wt% GO-OH to the detergent enhanced the foam drainage half-life of the detergent from 40 min to 68 min and improved the stability of the detergent by 70%. In addition, the synergistic action of GO-OH/SiO2 with TAS surfactant increased the liquid film thickness of the foam and the airflow resistance to support the weight-bearing capacity of the foam skeleton. As a result, it slowed the rate of foam disproportionation, reduced the bubble size, increased the bubble number, and finally improved the foam stability of the detergent. For simulated radioactive uranium pollutants on the surfaces of glass, stainless steel, and tiles, the foam detergent with the synergistic action of GO-OH/SiO2 and TAS surfactant had decontamination rates of 91.7%, 91.16% and 91.76%, respectively, which were 14.96%, 15.67% and 19.39% higher than that of TAS foam detergent without GO-OH/SiO2. The synergistic enhancement of GO-OH and SiO2 on foam stability and its adsorption and combination action with uranyl ions would be the main reasons to improve the detergency of the TAS foam detergent. Therefore, TAS foam detergent stabilized synergistically by GO-OH/SiO2 with high stability and efficient decontamination will be widely applied in nuclear emergencies and decommissioning decontamination of nuclear facilities.

Development of a low-cost photocatalytic aerogel based on cellulose, carbon nanotubes, and TiO2 nanoparticles for the degradation of organic dyes

A hybrid ultra-light and porous cellulose aerogel was prepared by extracting cellulose fibers from white paper, alkali/urea as a crosslinker agent, and functionalized with CNTs and pure anatase TiO2 nanoparticles. Since CNTs work as mechanical reinforcement for aerogels, physical and mechanical properties were measured. Besides, since TiO2 acts as a photocatalyst for degrading dyes (rhodamine B and methylene blue), UV–Vis spectroscopy under UV light, visible light, and darkroom was used to evaluate the degradation process. XRD, FTIR, and TGA were employed to characterize the structural and thermal properties of the composite. The nanostructured solid network of aerogels was visualized in SEM microscopy confirming the structural uniformity of cellulose and TiO2-CNTs onto fibers. Moreover, CLSM was used to study the nano-porous network distribution of cellulose fibers and porosity, and the functionalization process in a detailed way. Finally, the photocatalytic activity of aerogels was evaluated by degradation of dye aqueous solutions, with the best photocatalytic removal (>97 %) occurring after 110 min of UV irradiation. In addition, HPLC-MS facilitated the proposed mechanism for the degradation of dyes. These results confirm that cellulose aerogels coupled with nanomaterials enable the creation of economic support to reduce water pollution with higher decontamination rates.

Molten salts for efficient removal of radioactive contaminants from stainless steel surface: Mechanisms and applications

Here, we have demonstrated an innovative decontamination strategy using molten salts as a solvent to clean stubborn uranium contaminants on stainless steel surfaces. The aim of this work was to investigate the evolutionary path of contaminants in molten salts to reveal the decontamination mechanism, thus providing a basis for the practical application of the method. Thermodynamic analysis revealed that alkali metal hydroxides, carbonates, chlorides and nitrates can react with uranium oxides (UO3 and U3O8) to form various uranates. Notably, the decontamination mechanism was elucidated by analyzing the chemical composition of the contaminants in the molten salts and the surface morphology of the specimens considering NaOH–Na2CO3–NaCl melt as the decontaminant. The decontamination process involved two stages: a rapid decontamination stage dominated by the thermal effect of molten salt, and a stable decontamination stage governed by the chemical reactions and diffusion of molten salt. Subsequently, a multiple decontamination strategy was implemented to achieve high decontamination rates and low residual radioactivity. Within the actual cleaning time of 30 min, the decontamination efficiency (DE) of UO3-contaminated specimens reached 97.8% and 93.0% for U3O8-contaminated specimens. Simultaneously, the radioactivity levels of all specimens were reduced to below the control level for reuse in the nuclear domain. Particularly, the actual radioactive waste from the nuclear industry reached a reusable level of radioactivity after decontamination. The NaOH–Na2CO3–NaCl melt outperforms conventional chemical solvents and may be one of the most rapid and efficient decontaminants for stubborn uranium contamination of metal surfaces, which provides insights in regard to handling nuclear waste.

Floatable S-scheme Bi2WO6/C3N4/carbon fiber cloth composite photocatalyst for efficient water decontamination

The development of easily recyclable and advanced photosystems is a promising strategy for achieving sustainable water decontamination in industrial applications. In this study, a flexible, floatable, and easily recyclable S-scheme photosystem of oxygen vacancy (OV)-rich Bi2WO6/C3N4/carbon fiber cloth (BWOV/CN/CF) was fabricated via sequential in situ growth of C3N4 and Bi2WO6 with oxygen vacancies on CF cloth. The integrated BWOV/CN/CF photosystem exhibited outstanding photocatalytic decontamination rates for TC (0.0353 min−1) and Cr(VI) (0.0187 min−1), significantly exceeding CN/CF by 0.5 and 30.2 folds, respectively. This appreciable improvement is derived from the unique hierarchical S-scheme heterostructure with OV, which enables the enhanced capability of BWOV/CN/CF in light use and powerful photocarrier detachment, as well as offering abundant active centers. Significantly, the BWOV/CN/CF cloth shows intriguing industrial application prospects owing to its high anti-interference properties, broad pH applicability, good durability, easy recycling and operation, and extensive adaptability for diverse contaminant purification. Furthermore, the photocatalytic TC decomposition process, by-product biotoxicity, and photocatalysis mechanism were systematically evaluated. The ingenious design of floatable cloth-shaped photosystems offers an effective strategy for environmental purification.

Effects of Different Types of Stabilizers on the Properties of Foam Detergent Used for Radioactive Surface Contamination.

Compared with high-pressure water and reagent washing decontamination, foam decontamination has a promising application due to its ability to significantly reduce the volume of radioactive waste liquids and effectively decontaminate the inner surface of the pipes, the interior of the large cavities, and the vertical walls. However, the foam is less stable, leading to a low decontamination rate. Currently, three main types of stabilizers with different stabilizing mechanisms, namely nanoparticles, polymers, and cosurfactants, are used to improve foam stability and thus increase the decontamination rate. Nanosilica (NS), xanthan gum (XG), and n-tetradecanol (TD) were used as typical representatives of nanoparticles, polymers, and cosurfactants, respectively, to improve the stability of the foam detergent with pH < 2 and chelating agents. The differences in the effects of these three types of stabilizers on foam properties were investigated. Although NS, XG, and TD all increase the half-life of the foam from 7.2 min to about 40 min, the concentration of TD is much lower than that of NS and XG in the foaming solution, and TD foaming solution has the highest foaming ratio. Moreover, TD can markedly lower the surface tension, resulting in a significant reduction of the wetting contact angle on the surfaces of glass, ceramic tile, stainless steel, and paint, while NS and XG cannot signally change the surface tension and have no obvious effect on the wetting contact angle. At low shear rates, TD can increase the apparent viscosity of foam by two orders of magnitude, and the wall-hanging time of the foam on the vertical wall is more than 30 min. In contrast, NS and XG cause a limited increase in the apparent viscosity of the foam, and the wall-hanging times are both less than 5 min. In addition, TD foaming solution has excellent storage stability, and the storage time has no obvious effect on the performance of the foam. And after only three days of storage, NS undergoes severe agglomeration and precipitation in the foaming solution, resulting in a complete loss of the stabilizing effect. After 90 days of storage, the half-life of XG foam decreases by 26%. For simulated radioactive uranium contamination on both horizontal and vertical surfaces, TD can significantly improve the decontamination rate, especially for vertical surfaces, where TD can increase the single decontamination rate by more than 50%.

Fluid-flow effects in the reactive decontamination of porous materials driven by chemical swelling or contraction

Following the release of a chemical warfare agent, it is crucial for public health that the affected environment is entirely decontaminated. If the agent has seeped into a porous building material, the decontamination is achieved by applying a cleanser solution to the surface of the porous material, and allowing it to react in, neutralising the agent. Typically, the agent and cleanser solution are immiscible fluids and so the reaction occurs at the fluid–fluid interfaces within the pores. Previous studies have shown that the rate of decontamination of the porous material can depend on both the chemical reaction rate and the transport of cleanser to the reacting interface. These studies have all assumed that the two fluids have the same densities, so that diffusion is the only cleanser-transport mechanism. In this paper, we relax this assumption and investigate the effect of a fluid flow—generated by a change in density of the material (a swelling, or contraction) during the chemical reaction—on the decontamination process. This flow of fluid results in advection as well as diffusion of chemicals. Buoyancy effects are neglected. In particular, we show that when the agent is more dense than the reaction product, the decontamination process is slower, due to the adverse advection effect.

Ce(IV)-Based Metal-Organic Gel for Ultrafast Removal of Trace Arsenate from Water.

As a potential replacement for metal-organic frameworks (MOFs), constructing metal-organic gels (MOGs) is an appealing but challenging topic since MOGs are a kind of shapeable MOF gels. Also, the rapid adsorption of trace heavy metal ions in aqueous media remains a serious challenge. Herein, a simple strategy for the synthesis of Ce(IV)-based metal-organic gel (Ce-MOG) was first developed for the rapid adsorption of trace As(V). The (NH4)2Ce(NO3)6 obtains hydroxide bridges after adding apposite NaOH, leading to [Ce6O4(OH)4]12+ clustering and inducing fast and excessive nucleation rates, which also leads to coordination disturbance of MOF nanocrystals to obtain Ce-MOG. The Ce-OH groups are the key to gel formation through hydrogen bonding and are the active site for the ultrafast adsorption of As(V). As expected, the resultant Ce-MOG has an excellent adsorption rate, making it possible to effectively decontaminate 500 ppb of As(V) to below the World Health Organization (WHO) recommended threshold for drinking water (10 ppb) within 1 min. It achieves equilibrium adsorption in 10 min, and the final arsenate-removing efficiency reaches 99.8%. For Ce-MOF, the effluent concentration of As(V) is higher than the drinking water standard, while equilibrium adsorption takes 60 min. The initial adsorption rate of Ce-MOG, h(k2qe2) is calculated and indicated to be 67.67 mg g-1 min-1, about 19.96 times that of Ce-MOF (3.39 mg g-1 min-1). As such, the excellent As(V) decontamination rate, selectivity, and reusability of Ce-MOG indicate its great potential for practical drinking water purification.

Multiple chemical warfare agent simulant decontamination by self-driven microplasma

Low-temperature plasma is a green and high-efficiency technology for chemical warfare agent (CWA) decontamination. However, traditional plasma devices suffer from the problems of high-power composition and large power-supply size, which limit their practical applications. In this paper, a self-driven microplasma decontamination system, induced by a dielectric-dielectric rotary triboelectric nanogenerator (dd-rTENG), was innovatively proposed for the decontamination of CWA simulants. The microplasma was characterized via electrical measurements, optical emission spectra and ozone concentration detection. With an output voltage of −3460 V, the dd-rTENG can successfully excite microplasma in air. Reactive species, such as OH, O(1D), H α and O3 were detected. With input average power of 0.116 W, the decontamination rate of 2-chloroethyl ethyl sulfide reached 100% within 3 min of plasma treatment, while the decontamination rates of malathion and dimethyl methylphosphonate reached (65.92 ± 1.65)% and (60.88 ± 1.92)% after 7 min of plasma treatment, respectively. In addition, the decontamination rates gradually decreased with the increase in the simulant concentrations. Typical products were identified and analyzed. This study demonstrates the broad spectrum and feasibility of the dd-rTENG-microplasma for CWA elimination, which provides significant guidance for their practical applications in the future.

Experimentation and optimization of laser waterless decontamination rate of residual organic solvents

Laser waterless decontamination is a widely researched area for the high pollution issue of residual organic solvents in industry and agriculture. In this research, a nanosecond pulsed laser was used to conduct waterless decontamination studies on organic solvent residues on the surface of optical glass. A single-factor test was designed using the decontamination rate (Y) as the response value and the laser power (X1), scanning speed (X2), and decontamination times (X3) as the influencing variables. The Raman spectrum reflected the decontamination effect of organic solvent decontamination using a waterless laser. The Box-Behnken response surface method (RSM) was used to design the experiments. The developed RSM was used to determine the link between laser parameters and decontamination rate, and optimum decontamination parameters were determined. In addition, the mathematical model and regression equation were established using Design-Expert. The findings demonstrate that residual solvent may be removed at a rate of up to 95.22%. Optimum values for laser power, scanning speed, and decontamination times are 130 W, 381 mm/s, and 10 times respectively.

Decontamination of uranium-containing radioactive waste from stainless steel surfaces using NaOH-based molten salts.

Herein, we report a new strategy for the rapid removal of uranium-containing contaminants from metal surfaces, and it relies on decontaminants made of NaOH-based molten salts. The addition of Na2CO3 and NaCl to NaOH exhibited superior decontamination performance, with a decontamination rate of 93.8% within 12 min, outdoing the performance of the single NaOH molten salt. The experimental results demonstrated that the synergistic effects between CO32- and Cl- promoted the corrosion efficiency of the molten salt on the substrate, which accelerated the decontamination rate. Additionally, benefiting from the optimization of the experimental conditions by the response surface method (RSM), the decontamination efficiency was improved to 94.9%. Notably, it also showed remarkable results in the decontamination of specimens containing different uranium oxides at low and high levels of radioactivity. This technology is promising for broadening the path in rapid decontamination of radioactive contaminants on metal surfaces.

Removal of surface cesium ion contamination by peelable composite coating with a highly effective magnetic adsorbent

Conventional methods used during nuclear facility decommissioning to remove radioactive contamination from equipment surfaces produced a lot of trash and could result in secondary contamination. Peelable coatings, on the other hand, have been frequently employed for surface decontamination because of their great efficacy, peelability, flexibility, and compatibility with various substrates. Herein, we developed a novel efficient magnetic cesium ion adsorbent (Qmax = 249 mg/g) and combined it with polymers such as polyvinyl alcohol (PVA) to design a peelable composite coating. The composite coating can be used to decontaminate a variety of surfaces, including aluminum, plexiglas, marble, and stainless steel, with a combined decontamination efficiency of more than 95%, especially when applied to stainless steel surfaces with a decontamination rate of 98.69%. The coating also possesses excellent mechanical properties and recyclability, allowing easy recovery of the film-forming material and magnetic adsorbent recovery at the end of the decontamination process.

Tritium decontamination in vacuum vessel after deuterium plasma experiment due to air exposure

The deuterium plasma experiment using Large Helical Device (LHD) has been conducted since 2017. A small amount of tritium was produced in the vacuum vessel and a part of tritium remained in the plasma-facing materials. After the deuterium plasma experimental campaign, the vacuum vessel was opened for the LHD maintenance activity. Then, the plasma-facing material was exposed to room air and remained tritium was released at ambient temperature. The tritium release rate increased rapidly immediately after the vacuum vessel was opened to the atmosphere, but it turned to decrease soon after. After several weeks of opening the vacuum vessel, the tritium release rate became low and almost constant. The total tritium decontamination rate, defined as the ratio of tritium released by air exposure to tritium produced during the plasma experimental campaign, was achieved at several percent. The air exposure operation is expected to have a decontamination effect due to isotope exchange reactions on the surface of the plasma-facing material.

SG-APSIC1112: The quality enhancement in sterilization processes at Naresuan University Hospital

Background: Disinfection and sterilization of medical devices, instruments, and medical supplies are a crucial part of hospital infection control. The significant problems include insufficient cleaning, incorrect registration in the request form, no basic cleaning at the point of use (POS), and incorrect labelling. These problems were analyzed according using the fishbone diagram process. Objectives: We sought to decrease insufficient cleanliness of items after washing, to increase data accuracy in transferring contaminated devices from wards (from end users), to increase the rate of decontamination at the point of use, and to decrease incorrect labelling on instrument packaging. Method: The Community of Practice in Sterilization (CoP Sterile) team revised the disinfection and sterilization system of the Naresuan University Hospital Central Sterile Supply Department (CSSD) using root-cause analysis of subprocess problems and implementing prioritized solutions. A regular monthly meeting was set up to ensure active response, and closed monitoring was performed to ensure the implementation of the revised protocol according to the plan–do–study–act (PDSA) process. Results: From 2019 to 2021, the percentages of annual insufficient cleanliness of items after washing decreased from 4.8% to 3.6% to 3.1% each year. The percentages of incorrect request forms decreased from 14.59% to 2.91% to 1.84% during these same years. The percentages of decontamination ignorance at the point of use decreased from 3.13% to 0.12% to 0.03% from 2019 to 2021. The percentages of incorrect labelling were 0.013%, 0.008%, and 0.013% each year. Conclusions: The CoP Sterile team used quality improvement tools and regular monitoring to achieve reductions in insufficient cleanliness and incorrect request forms and to increase knowledge of decontamination procedures.

Bioremediation of Polycyclic Aromatic Hydrocarbons in Contaminated Soils Using Vermicompost

Bioremediation of polycyclic aromatic hydrocarbons (PAHs) in contaminated soils are reported in many literatures. Composting, in addition to bioremediation, can simultaneously increase soil organic matter content and soil fertility and is thus regarded as one of the most cost-effective methods of soil remediation. In this study, biodegradation of phenanthrene (PHE) and pyrene (PYR) is reported by microbial consortia enriched by vermicompost. After soil samples preparation and grinding, the samples were contaminated with 100, 200, and 300 mg/kg of PHE and PYR concentrations and inoculated with three concentrations (2, 4, and 6 wt.%) of vermicompost. PHE and PYR concentrations were analyzed by HPLC during bioremediation. After 70 days, two highly capable microbial consortia were used to remove the pollutants in bioaugmentation conditions. Analysis of their microbial composition revealed that the consortia contain several Proteobacteria phylum bacterial species, and the most common genera were Pseudomonas and Citrobacter. Decontamination rates for PHE and PYR were estimated to be 89% and 83% over 45 days, respectively. Biodegradation kinetics revealed that microbial degradation followed a first-order kinetics. This study provides clear evidence on the biodegradation of PHE and PYR, paving the way for the development of bioremediation technologies for the recovery of polluted ecosystems.

Boost piezocatalytic activity of BaSO4 by coupling it with BaTiO3, Cu:BaTiO3, Fe:BaTiO3, S:BaTiO3 and modify them by sucrose for water purification

The purpose of this study is to improve the efficiency of decontamination using BaSO4 as a piezocatalyst. Three techniques are employed in this study to enhance the piezocatalytic activity of BaSO4. The first method involves coupling BaSO4 with BaTiO3. The acid red 151 and acid blue 113 decontamination rates improved from 56.7% and 60.9% to 61.3% and 64.4%, respectively, as a result of this strategy. Additionally, the composite of BaSO4 and BaTiO3 was doped with copper, iron, sulfur, and nitrogen. By doping BaTiO3, acid red 151 and acid blue 113 achieved 86.7% and 89.2% efficiency, respectively. Finally, the nanostructures were modified with sucrose. These strategies improved degradation efficiency for acid red 151 and acid blue 113 to 92.9% and 93.3%, respectively. The reusability results showed that the piezo-catalytic activity of the m-S–BaSO4–BaTiO3 catalyst did not show a significant loss after five recycles for the degradation of AB113.