Removal Of Contaminants Research Articles

Can Salvinia auriculata bioremediate the toxic effects of Fipronil 800wg on the tadpoles of Dendropsophus minutus?

Worldwide, the indiscriminate and escalating application of pesticides has led to extensive impacts on both the environment and non-target organisms. Phytoremediation, which employs plants to decontaminate environments, is a potential strategy for the mitigation of this damage. The present study assessed the phytoremedial potential of Salvinia auriculata, an aquatic macrophyte known to be effective for the removal of environmental contaminants. In the laboratory, Dendropsophus minutus tadpoles were exposed to different concentrations (0.035, 0.1, 1.0, and 1.5 mg/l) of the commercial insecticide Fipronil 800wg in two treatments – (i) simple exposure for 96 hours, and (ii) exposure for 168 hours in aquariums containing S. auriculata. In the first experiment, a mortality rate of 33.3% was recorded at the highest fipronil concentration (1.5 mg/l), and genotoxic parameters increased at all concentrations except 0.035 mg/L, in comparison with the control. In the second experiment, phytoremediation occurred at all the concentrations tested, with lower frequencies of cells with micronuclei, and binucleated, anucleated, and pyknotic nuclei being observed, in comparison with the first experiment. These findings highlight the potential effectiveness of S. auriculata for the phytoremediation of environments contaminated by pesticides and contribute to the understanding of the benefits of this approach for the protection and preservation of aquatic biodiversity.

A Developed Novel Hal′@MIL-PMA Triple Composite Utilized as a Robust Photocatalyst for Activated Removal of Antibiotic Contaminants: A new chemical mechanism for Tetracycline degradation

In this research an appreciable Hal′@MIL-PMA photocatalyst was prepared through a hydrothermal approach to photo-oxidize Tetracycline. The as-fabricated composite was diagnosed by multiple catalyst characterization tests, including XRD, FTIR, FESEM, PL, EIS, EDS, TGA, BET, and DRS techniques. Under optimized conditions (i.e.; a 1g/L dosage of photocatalyst, antibiotic concentration of 40mg/L, pH = 7 and at ambient temperature), 97.11% of Tetracycline elimination was achieved by the pristine Hal′@MIL-PMA photocatalyst. Kinetics computation revealed that the photo-degradation rate of Tetracycline obeys the pseudo-first-order model. Tests on radical trapping manifested that hydroxyl radical was a predominant oxidating reactive agent during the photocatalysis process. The mechanistic decontamination route of Tetracycline was deduced on the basis of the detected transformation products. The decay rate of TOC (63.23%) displayed that the Tetracycline was transferred to H2O, CO2, and simple degradable substances during the photocatalysis procedure. Additionally, the photocatalytic mechanism of Tetracycline degradation over the Hal′@MIL-PMA heterojunction photocatalyst was presented. The as-fabricated photocatalyst displayed significant oxidation efficiency in degrading multiple antibiotics, such as Rifampicin (90.87%) and Sulfasalazine (95.31%) under the above determined optimized conditions. Besides, the photocatalytic rate of Hal′@MIL-PMA heterostructured composite had no remarkable diminish even after five consecutive cycles. On the whole, this investigation evinces that Hal′@MIL-PMA composite can be regarded as a sustainable and promising photocatalyst for decontaminating non-biodegradable and tenacious substances from aqueous environments.

Fiber-based super-bridging agents improve flotation and settling during water treatment

Increasing demand for water poses a major challenge to the water treatment industry. Consequently, water treatment plants are expected to require larger separation units and use more chemicals. Physicochemical treatments produce flocs that are limited in size, which limits floc removal efficiency during gravitational separation. Introducing fiber-based super-bridging agents has improved the floc size, which is 10–100 times larger than conventional flocs. Such improvements could lead to important gains in floc separation and ultimately increase the capacity of water treatment plants. This study analyzed the behavior and interaction of fibers under various coagulation/flocculation conditions to improve flotation and settling. The results also showed that fibers can allow a ~ 50 % reduction in coagulant. The benefits of fibers on floc size were particularly pronounced during suboptimal coagulation, as the injection of fibers compensated for poor coagulation conditions. Air bubbles during air flotation were also better incorporated into the larger and more porous floc structure obtained with fibers, which drastically improved floc removal during flotation. The best turbidity removal after flotation was obtained when combining 2 mg of cationic polyacrylamide and 200 mg of softwood fibers/L. Fiber-based super-bridging agents can be introduced in existing water treatment plants to increase plant capacity, reduce the demand for coagulants/flocculants, and improve contaminant removal.

Diesel Fuel Stripping Systems for Enhanced Fuel Quality and Performance

Diesel fuel quality is essential for efficient engine performance, but stored diesel can accumulate contaminants over time, impacting engine efficiency and increasing maintenance costs. Diesel stripping systems, such as diesel strippers or diesel fuel polishing systems, play a crucial role in addressing these issues by effectively removing impurities and ensuring fuel purity. This paper examines the design, engineering, and operational aspects of diesel stripping systems, focusing on their ability to enhance fuel quality and optimize engine performance. Components like filters, pumps, separators, and steam stripping units work together, with steam stripping being a key method for removing light ends and hydrogen sulfide (H2S) from diesel. Design considerations, including system integration, material selection, and safety features, are critical for system effectiveness and reliability. Performance testing and maintenance practices ensure compliance with contaminant removal standards and sustain system efficiency. This research contributes to advancing diesel fuel management practices and identifies future trends for improved efficiency and environmental sustainability in diesel fuel purification technologies

Water Quality and the First-Flush Effect in Roof-Based Rainwater Harvesting, Part II: First Flush

Rainwater runoff samples from a range of roofing materials were temporally collected from 19 small-scale roof structures and two commercial buildings through simulated and actual storm events, and the concentrations of polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFLs), and pyrethroid insecticides and other water quality parameters were analyzed. In Part I of this research, the concentrations of these contaminants in roof runoff and soils receiving runoff from a range of roofing materials were evaluated. In Part II, recommendations have been developed for a first-flush exclusion to improve the quality of water harvesting for nonpotable uses. Recommendations focus on a first-flush diversion based on mass removals of total suspended solids (TSS) and PAHs linked to conductivity measurements throughout a storm event. Additionally, an upper-confidence limit (UCL) was constructed to determine the minimum diversion required to obtain 50, 75, 90, and 95% mass removal of TSS and PAH contaminants. The majority of TSS were produced during the initial 1.2 mm of runoff. Likewise, the majority of PAHs were removed during the initial 1.2 mm of runoff, except for the asphalt shingle roofs, where high PAHs were observed after 6 mm of runoff. The Texas Water Development Board (TWDB)-recommended first-flush diversion of one gallon for every 100 square feet of rooftop was not always adequate for removing 50% of TSS and PAHs from the roofs. Rainwater runoff conductivity decreased drastically between 1.2 to 2.4 mm of rainwater runoff. Diverting the first flush based on conductivity has the potential to also divert the majority of TSS and PAHs in roof runoff.

Removal and Reoccurrence of LLZTO Surface Contaminants under Glovebox Conditions.

The reactivity of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) solid electrolytes to form lithio-phobic species such as Li2CO3 on their surface when exposed to trace amounts of H2O and CO2 limits the progress of LLZTO-based solid-state batteries. Various treatments, such as annealing LLZTO within a glovebox or acid etching, aim at removing the surface contaminants, but a comprehensive understanding of the evolving LLZTO surface chemistry during and after these treatments is lacking. Here, glovebox-like H2O and CO2 conditions were recreated in a near ambient pressure X-ray photoelectron spectroscopy chamber to analyze the LLZTO surface under realistic conditions. We find that annealing LLZTO at 600 °C in this atmosphere effectively removes the surface contaminants, but a significant level of contamination reappears upon cooling down. In contrast, HCl(aq) acid etching demonstrates superior Li2CO3 removal and stable surface chemistry post treatment. To avoid air exposure during the acid treatment, an anhydrous HCl solution in diethyl ether was used directly within the glovebox. This novel acid etching strategy delivers the lowest lithium/LLZTO interfacial resistance and the highest critical current density.

Hydrothermally Produced Activated Carbon Impregnated with ZnO for the Adsorptive Removal of Toxic Pharmaceutical Contaminants from Aqueous Solution

This research explores the adsorption (AD) of diclofenac sodium (DS) onto a Hydrothermally produced activated carbon impregnated with ZnO (HTC-AC/ZnO) surface, considering various factors such as initial concentration (IC), adsorbent dose, contact time, and pH. The characterization of HTC-AC/ZnO was performed using X-ray diffractometer (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), and nitrogen physisorption spectroscopy (BET). Tests were conducted with different adsorbent doses (0.5–4 g/L) at 303 K and various initial diclofenac concentrations (ranging from 50 mg/L to 250 mg/L) to observe their effects. Additionally, pH values were altered from 2 to 12 to study their influence on AD. Kinetic studies, thermodynamic studies, and AD isotherm models were examined. The Temkin isotherm model (TIM) was found to be the most accurate for DS-AD on HTC-AC/ZnO. For DS-AD on HTC-AC/ZnO, pseudo-first-order models (PFOM), intraparticle diffusion model (IPDM), and pseudo-second-order models (PSOM) were applied, with a correlation coefficient of 0.945, indicating a good fit for PFOM. The kinetics suggested rapid adsorption. Notably, the HTC-AC/ZnO composite exhibited consistent AD characteristics across four consecutive cycles, with a removal efficiency exceeding 99.38%. This suggests that HTC-AC/ZnO is an appropriate and economically viable adsorbent for the elimination of DS from water-based solutions. The investigation provides compelling evidence that HTC-AC/ZnO is a viable adsorbent for the effective elimination of DS from water sources.

Contribution of early succession regeneration plants to heavy metal remediation in abandoned Artisanal small-scale mining sites in Ghana

Artisanal Small-Scale mining (ASM) is a major land use activity in Ghana. Despite its tremendous contribution to livelihoods, ASM is largely unregulated in the country, illegally operated, leaving most mined out sites unrehabilitated. In this study, we explored the extent to which early succession naturally regenerating plants on two abandoned illegal artisanal small scale mined-out sites (Chamfi and Alluvial types) remediate heavy metals. The study was undertaken in three districts of the Western Region of Ghana. Plots were randomly established in the alluvial, chamfi and reference (control) sites. Within each plot, samples of soil and naturally regenerating plants were collected for determination of bioaccumulation potential, translocation and contamination factor of cadmium (Cd), arsenic (As), lead (Pb), and mercury (Hg) using the Atomic Absorption Spectrophotometer. The results revealed that the concentration of As, Cd, Hg, Pb from soil samples, as well as roots and shoots of the plants collected from the two mined sites were significantly higher than the concentrations in the samples from the control plots. Our results show that heavy metal removal is more significant in plants at the alluvial mined soils than those at the chamfi sites. C. pubescens, C. odorata, and M. pudica were observed to be better cadmium translocators than the other vegetations sampled. Furthermore, plants at the alluvial sites recorded higher Bioaccumulation Factor (BF) in the roots than those at the chamfi sites for lead and arsenic. The study implies that natural regeneration of early successional species can promote contaminant removal on abandoned artisanal mine sites. They however vary in their capacity to accumulate different metals on abandoned soils. Within the context of illegal ASM prevalence, our results suggest that efforts should be made to encourage and minimize disturbances to the growth of early succession plant species as short-term alternative measures in abandoned artisanal mined sites, where reclamation is often neglected.

Photoelectrocatalysis/photoelectro-Fenton system based on cone-like TiO2/nickel foam photoanode for efficient degradation of carbamazepine: Comparison with DSA

To degrade refractory organics in wastewater more efficiently and with lower energy consumption, cone-like TiO2 was grown on nickel foam (NF) and coupled with natural air-diffusion electrode (NADE) to construct novel photoelectrocatalysis/photoelectro-Fenton (PEC/PEF) system, which could completely remove 10 mg/L of carbamazepine (CBZ) within 30 min (with a pseudo-first-order rate constant (k) of 0.1939 min−1). And the system was driven by only 2 mA of current (1.7 V cell potential) with an electrical energy per order (EEO) of only 0.005 kWh m−3 order-1. It took the lead in contaminant removal and energy consumption when compared with conventional PEF systems based on dimensionally stable anode (DSA). The synergy coefficient of PEC/PEF system was as high as 6.14, which was 6.5 times that of PEF system. The reaction mechanism different from PEF system was revealed, in which e--h+ pairs were generated at TiO2/nickel foam (TiO2/NF) under UV irradiation, e- transferred to NADE enhanced current density thus promoted H2O2 accumulation much more than that using DSA. The direct oxidation of h+ and the more •OH (6.17 μM vs. 5.82 μM) produced by H2O2 utilization were the reasons for higher degradation efficiency in PEC/PEF process. Our PEC/PEF system provides a new idea for low energy consumption and high efficiency removal of pollutants, it is promising for the application to the treatment of refractory organics in wastewater.

Heat Treatment of Calcite to Enhance Its Removal of Color Dye Alizarin Red S

The use of color dyes in modern society presents a great challenge to the environment. Thus, extensive studies have been conducted in the last 30 years on the removal of color dyes from aqueous solutions such industrial wastewater. In this study, the removal of alizarin red S (ARS), an anionic dye, from solution by raw calcite (Cal) and heat-treated calcite (HCal) was conducted and compared under different physico-chemical conditions. Based on the isotherm study, the ARS removal capacities increased from 167 to 251 mmol/kg after the Cal was heated to 1000 °C for 3 h. The X-ray diffraction analyses showed no difference in the calcite phase between Cal and HCal after ARS sorption. Fourier-transform infrared results also showed no change in the calcite phase after ARS sorption, except a slightly increase in wavenumber from 713 to 727 cm−1 for the OCO bending of HCal at high ARS sorption levels. SEM observations showed about the same particle size and morphology before and after ARS sorption. The TGA data showed the formation of CaO after Cal was heated, and CaO converted back into calcite after being in contact with water or ARS solution for 24 h and then being air-dried. Thus, the high ARS removal could be due to CaO produced after Cal being heated. The findings from this research proved that there is great potential in the use of calcite, a low-cost and readily available Earth material, after heat treatment for the removal of contaminants from water.

Non-radical activation of peroxymonosulfate by modified activated carbon for efficient degradation of oxytetracycline: Mechanisms and applications

The application of heterogeneous metal-free catalysis for non-radical peroxymonosulfate (PMS) oxidation is of great significance because of its low environmental effects and mild oxidant dosage. The purpose of this study was to investigate the activation mechanism of PMS using acid-modified activated carbon and oxytetracycline (OTC) as a representative pollutant. Modified activated carbon (MAC)/PMS system was capable of achieving 100 % degradation efficiency of OTC within 60 min, with an observed rate constant (kobs) of 0.0414 min−1. The degradation of OTC is dominated by non-radical oxidation pathways involved in mediated singlet oxygen (1O2) and electron-transfer process through electron paramagnetic resonance (EPR) and radicals quenching studies. The activation of PMS is attributed to the structural defects of MAC, persistent free radicals, and oxygen functional groups such as C-OOH. Moreover, the MAC/PMS system consistently demonstrates high and reliable contaminant removal in various water matrices. A continuous-flow device utilizing MAC shows excellent performance in purifying micro-polluted water. Additionally, the degradation pathways of pollutants and changes in toxicity during the degradation process were identified through density functional theory (DFT) calculations, liquid chromatography-mass spectrometry (LC-MS), and toxicological analysis. Finally, the cultivation of green beans, peas, and wheat was found to significantly decrease the toxicity of contaminated water through degradation. This study proposes a low-cost method to enhance the activation pathway of non-radical PMS by utilizing modified activated carbon materials for pollutant remediation.

Evaluation of ventilation and indoor air quality inside bedrooms of an elderly care centre

Ventilation and indoor air quality are important factors that affect the health of the elderly. The purpose of this study was to find effective ventilation design measures for improving ventilation and air quality in typical two-bed bedrooms in elderly care centres (ECCs). Mixing ventilation (MV), displacement ventilation (DV), zone ventilation (ZV) and stratum ventilation (SV) were analysed with twelve scenarios to find the most effective ventilation design solutions including six scenarios with curtains between the beds and six scenarios without curtains between the beds. Airflow distribution, CO2 concentration, ventilation efficiency and health risk assessment were adopted for discussion. SV was found to be an effective method for improving air quality in the ECC bedroom while also taking into account the needs and rights of elderly residents, such as privacy. Comparing scenarios with and without curtains between beds under same types of ventilation, scenarios without curtains showed a slight (≤8%) decrease in CO2 concentration in the pillow area. However, this could increase virus transmission risk and compromise elderly privacy, so it is not recommended. Regarding the scenarios with curtains between the beds, the contaminant removal efficiency (CRE) of scenarios using SV was increased by 2.58, 3.22 and 2.12 times compared to the scenarios using MV, DV, and ZV respectively. Additionally, the health ratio (HR) of SV was reduced by 46.3 %, 53.7 %, and 41.7 %. Hence, it is recommended to install curtains between the beds and apply SV in ECC bedrooms. This study can be used as a guide for systematically designing ventilation systems in ECC bedrooms. Furthermore, collaboration among environmental engineers, designers, policymakers, and the wider community is essential to develop sustainable indoor environments for the elderly.

Self-assembly formation of Co quantum dot loaded N-doped porous carbon cathode for quinoline degradation in the electro-Fenton system

Quinoline is high toxicity and difficult biodegradation in oil washing wastewater. Therefore, efficient removal of quinoline contaminant from water bodies poses a major challenge. Hence, Co quantum dot loaded N-doped porous carbon (CoNC) nanosheets grown in situ on carbon cloth were fabricated as cathode for the degradation of quinoline in electro-Fenton system. Under optimal conditions (c(Fe2+) = 0.5 mM, U = -0.3 V, pH = 3), quinoline was completely degraded within 15 min with superior apparent rate constant of 0.385 min−1, which was 19.6 times higher than that of the ZIF-L precursor, due to the abundance of Co QDs active sites and hydrophilicity and electrical conductivity of N-doped porous carbon. In addition, three reaction pathways for quinoline were deduced by combining Density Functional Theory (DFT) calculation and Liquid Chromatography-Mass Spectrometry (LC-MS). More importantly, in situ FTIR and free energy calculations were analyzed to reveal that pathway Ⅰ as spontaneous reaction was the main reaction pathway. Finally, the toxicity of the intermediates was assessed with ECOSAR software and E. coli experiments, and the overall toxicity decreased during the degradation reactions. This work provides novel perspectives on environmental protection by designing in-situ grown cathodes through self-assembly method, thereby effectively purifying pollutants from wastewater.

Surface functionalization of reed beads with pentaethylenehexamine for improved dual contaminant removal

Surface functionalization of reed beads with pentaethylenehexamine for improved dual contaminant removal

Bubbleless membrane contactor for enhanced ozone mass transfer and ozonation for water purification

Membrane contactor, a physical barrier separating two phases to introduce gas into aqueous solutions through the bubbleless process, has gained considerable development for its improved gas transfer and contaminant removal efficiencies for water purification. However, a comprehensive assessment of a contactor with liquid flowing on the shell side and gaseous ozone flowing on the lumen side is scarce for ozonation. Therefore, we have developed a membrane contactor equipped with commercial hydrophobic polytetrafluoroethylene (PTFE) hollow fibers and investigated theoretically and experimentally the interaction between ozone and solution. Mass transfer behavior was evaluated by comparing experimental value and computational model of corresponding coefficients. Phenol was then selected as a model contaminant to evaluate the treatment performance of membrane contactors in ozonation. Crucial operating conditions involving the gas/liquid flow rate, concentrations of ozone and phenol, pH and geometry of fibers were assessed for their impacts on both ozone mass transfer and pollutant degradation. The results showed that the membrane presented high chemical resistance to ozone and could achieve stable mass transfer through bubbleless aeration. Under the optimum operating conditions, the overall liquid mass transfer coefficient was 1.12 × 10−5 m/s. The percentage removal and mineralization of phenol with 30 min hydraulic retention time could reach ∼100 % and 21.1 %, respectively, which have demonstrated the high treatment efficiency of the membrane contactor as an alternative technique in water purification.

Aerobic granulation and bioresource production under intermittent saline stress

Aerobic Granular Sludge (AGS) systems have gained prominence for liquid waste treatment and bioresource recovery. In this regard, various strategies are employed to accelerate granulation processes in sequencing batch reactors (SBRs) and maximize stability and bioresource production. Intermittent stress supplementation can facilitate granule development, promoting slow-growth microorganisms. At the same time, osmotic stress may enhance bioresource production. In this study, an AGS reactor control with no saline stress (R1) was compared to two AGS systems operated under constant (R2) and intermittent (R3) saline stress in terms of efficiency, stability and bioresource productions (alginate-like exopolysaccharides-ALE and tryptophan). Granulation occurred around day 59 and 21 in R2 and R3, respectively, while complete granulation was not achieved in R1 within the 80-day operational period. However, SBRs performed well after 45 days, with 70% of the biomass being granular. The production of the biopolymer ALE remained more stable in reactors with osmotic stress compared to R1. The microbiological analysis revealed specific responses and adaptations to environmental factors, with genera such as Thauera and Pseudofulvimonas showing higher abundance in reactors with complete granulation, indicating a positive correlation with saline conditions (5 g/L). These insights are crucial for optimizing the performance of AGS systems in future applications, emphasizing the benefits of intermittent saline stress in promoting rapid granulation, stability in bioresource production, contaminant removal, and robust granule formation.

Narrow spectrum nano-antibiotic for selective removal of ARB from contaminated water: New insights into stimuli response based on cellular attachment, lysis, and excretion

Narrow spectrum nano-antibiotics are supposedly the future trouble-shooters to improve the efficacy of conventional antimicrobials for treatment of severe bacterial infections, remove contamination from water and diminish the development of antibiotic resistance. In this study, antimicrobial peptide functionalized boron-carbon-nitride nanosheets ((Ant)pep@BCN NSs) are developed that are a promising wastewater disinfector and antibiotic resistant bactericide agent. These nanosheets are developed for selective removal and effective inactivation of antibiotic resistant bacteria (ARB) from water in presence of two virulent bacteria. The (Ant)pep@BCN NSs provide reactive surface receptors specific to the ARB. They mimic muralytic enzymes to damage the cell membrane of ARB. These NSs demonstrate 3-fold higher antimicrobial efficiency against the targeted ARB compared to pristine BCN even at lower concentrations. To the best of our knowledge, this is the first time that functionalized BCN has been developed to remove ARB selectively from wastewater. Furthermore, the (Ant)pep@BCN selectively reduced the microbiological load and led to morphological changes in Gram negative ARB in a mixed bacterial inoculum. These ARBs excreted outer–inner membrane vesicles (OIMVs) of triangular shape as a stimuli response to (Ant)pep@BCN NSs. These novel antimicrobial peptide-NSs have potential to improve treatment efficacy against ARB infections and water contamination.

Heavy Metal Stress Management through Phytoremediation to Mitigate Climate Change Impacts: An Overview

Plant stresses are the conditions that adversely affect the growth, development, or productivity of plants/trees and can be caused by various physical, chemical, and biological factors. However, stress caused by the influence of heavy metals has a notable adverse effect on plant growth and productivity. These heavy metal contaminations are responsible for the harmful effects on biotic (plants and associated organisms) and the abiotic (soil, water, and air) environment. If not properly managed, mining activities are considered to be the prime source of heavy metal contamination in the surrounding environment. Phytoremediation may effectively remediate a wide range of heavy metal contaminants in different environments and hence offers an effective, carbon-neutral, and ecologically beneficial method for the removal of hazardous heavy metal contaminants. Phytoremediation enhances the growth and development of plants and nourishes the environment resulting in the ill effects of climate extremes in disturbed areas and hence mitigating the impacts of climate change. Phytoremediation has been widely studied for the remediation of heavy metal stress but it hasn't yet achieved commercial viability in degraded ecosystems of India where it is required the most. Through this review article, we tried to minimize this gap by reviewing some important phytoremediation studies in India which successfully reduced the negative impacts of heavy metals in different degraded ecosystems.

Approaches for Enhancing Wastewater Treatment of Photocatalytic Fuel Cells: A Review.

Environmental pollution and energy crises have garnered global attention. The substantial discharge of organic waste into water bodies has led to profound environmental contamination. Photocatalytic fuel cells (PFCs) enabling the simultaneous removal of refractory contaminants and recovery of the chemical energy contained in organic pollutants provides a potential strategy to solve environmental issues and the energy crisis. This review will discuss the fundamentals, working principle, and configuration development of PFCs and photocatalytic microbial fuel cells (PMFCs). We particularly focus on the strategies for improving the wastewater treatment performance of PFCs/PMFCs in terms of coupled advanced oxidation processes, the rational design of high-efficiency electrodes, and the strengthening of the mass transfer process. The significant potential of PFCs/PMFCs in various fields is further discussed in detail. This review is intended to provide some guidance for the better implementation and widespread adoption of PFC wastewater treatment technologies.

Ventilation performance evaluation of an operating room with temperature-controlled airflow system in contaminant control: A numerical study

This article investigates the efficacy of temperature-controlled airflow systems in modern operating rooms for contaminant control, a critical factor in preventing surgical site infections. We have conducted experimental measurements in an operating room equipped with temperature-controlled ventilation to map the airflow field and contaminant dispersion (airborne particles with diameters ranging from 0.5‒1 μm). The results were used to validate the computational fluid dynamics code, which was then employed to simulate and examine different conditions, including contaminant release locations and air supply rates. Realizable k-epsilon and passive scalar models were utilized to simulate airflow and airborne particle phases. We assessed the airflow distribution and contaminant dispersion, utilizing indices such as ventilation and air change efficiency scales. The analysis provided quantitative insights into the distribution and removal of contaminants, as well as the speed at which the room air was replaced. Contamination was found to be effectively reduced when contaminants were released near exhaust outlets or under central unidirectional inlets. The presence of the operating table caused a big distortion of the central downward airflow, forming a horizontal air barrier at the periphery. Under this unique interior configuration, an appropriate air supply ratio between central and periphery zones was required to achieve optimal overall ventilation performance.