Search Results (62)

Endotoxins, lipopolysaccharides released from the outer membrane of Gram-negative bacteria, pose a significant risk in healthcare environments, particularly in Central Sterile Supply Departments (CSSDs), where the delivery of sterile pyrogen-free medical devices is critical for patient safety. Traditional methods for controlling endotoxins in water systems, such as ultraviolet (UV) disinfection, have proven ineffective at reducing endotoxin concentrations to comply with regulatory standards (<0.25 EU/mL). This limitation presents a significant challenge, especially in the context of reverse osmosis (RO) permeate used in CSSDs, where water typically has very low conductivity. Despite the established importance of endotoxin removal, a gap in the literature exists regarding effective chemical-free methods that can meet the stringent endotoxin limits in such low-conductivity environments. This study addresses this gap by evaluating the effectiveness of the eBooster™ electrochemical technology—featuring proprietary electrode materials and a reactor design optimized for potable water—for endotoxin removal from water, specifically under the low-conductivity conditions typical of RO permeate. Laboratory experiments using the B250 reactor achieved >90% endotoxin reduction (from 1.2 EU/mL to <0.1 EU/mL) at flow rates ≤5 L/min and current densities of 0.45–2.7 mA/cm². Additional real-world testing at three hospitals showed that the eBooster™ unit, when installed in the RO tank recirculation loop, consistently reduced endotoxin levels from 0.76 EU/mL (with UV) to <0.05 EU/mL over 24 months of operation, while heterotrophic plate counts dropped from 190 to <1 CFU/100 mL. Statistical analysis confirmed the reproducibility and flow-rate dependence of the removal efficiency. Limitations observed included reduced efficacy at higher flow rates, the need for sufficient residence time, and a temporary performance decline after two years due to a power fault, which was promptly corrected. Compared to earlier approaches, eBooster™ demonstrated superior performance in low-conductivity environments without added chemicals or significant maintenance. These findings highlight the strength and novelty of eBooster™ as a reliable, chemical-free, and maintenance-friendly alternative to traditional UV disinfection systems, offering a promising solution for critical water treatment applications in healthcare environments. Full article

This study focuses on the design and optimization of a monopolar electrode configuration for the hybrid electrochemical treatment of real washing machine wastewater. A combined electrocoagulation (EC) and electro-oxidation (EO) system was optimized to maximize pollutant removal efficiency while minimizing energy consumption. The monopolar setup employed mixed metal oxide (MMO) and aluminum anodes, along with a stainless steel cathode, operating under controlled conditions with sodium chloride as the supporting electrolyte. An applied current density of 15 mA cm⁻² achieved 90% chemical oxygen demand (COD) removal, 98% surfactant degradation, complete turbidity reduction within 120 min, and pH stabilization near 8. Additionally, electrochemical disinfection achieved <2 MPN/100 mL, with no detectable phenols and the presence of organic anions such as oxalate and acetate. These results demonstrate the effectiveness of an optimized monopolar EC–EO system as a cost-efficient and sustainable strategy for wastewater treatment and potential water reuse. Further studies should focus on refining energy consumption and monitoring reaction by-products to enhance large-scale applicability. Full article

This paper applies a semi-quantitative approach to review the diversity, environmental controls, detection methods, human health risks, and mitigation of cyanotoxins in drinking water systems (DWSs). It discusses the environmental factors controlling the occurrence of cyanotoxins, presents the merits and limitations of emerging methods of their detection (qPCR, liquid chromatography–mass spectrometry, and electrochemical biosensors), and outlines the human exposure pathways and health outcomes with identification of high-risk groups and settings. High-risk groups include (1) communities relying on untreated drinking water from unsafe, polluted water sources and (2) low-income countries where cyanotoxins are not routinely monitored in DWSs. The fate and behavior processes are discussed, including removing cyanotoxins in DWSs based on conventional and advanced treatment processes. The available methods for cyanotoxin removal presented in this paper include (1) polymer-based adsorbents, (2) coagulation/flocculation, (3) advanced oxidation processes, (4) ultra- and nanofiltration, and (5) multi-soil layer systems. Future research should address (1) detection and fate in storage and conveyance facilities and at the point of consumption, (2) degradation pathways and toxicity of by-products or metabolites, (3) interactive health effects of cyanotoxins with legacy and emerging contaminants, (4) removal by low-cost treatment techniques (e.g., solar disinfection, boiling, bio-sand filtration, and chlorination), (5) quantitative health risk profiling of high-risk groups, and (6) epidemiological studies to link the prevalence of human health outcomes (e.g., cancer) to cyanotoxins in DWSs. Full article

To address the limitations of conventional antibacterial therapies, we developed an injectable, conductive polyurethane-based composite gel system for sustained root canal disinfection. This gel incorporates piezoelectric nanoparticles (n-BaTiO₃) and conductive segments (aniline trimer, AT) within a polyurethane matrix, which synergistically interact with a static antimicrobial agent (n-ZnO) to achieve dynamic, mechano-responsive antibacterial activity. Under cyclic compression (simulating mastication), the piezoelectric gels exhibited enhanced electroactivity via the mechano-electric coupling effect, generating 2-fold higher voltage and a 1.8–1.9× increase in current compared to non-piezoelectric controls. The dynamic electroactivity of the gels enabled superior long-term performance, achieving 92–97% biofilm eradication, significantly higher than the static n-ZnO-only gel (88%). XPS and UV-vis spectroscopy analyses confirmed mechano-electrochemically amplified reactive oxygen species (ROS) generation, which contributed to improved biofilm disruption. The ISO-compliant gel provides durable, load-responsive disinfection while maintaining good biocompatibility, offering a promising solution to prevent post-treatment reinfection. Full article

Ensuring microbial safety in drinking water distribution networks is a critical challenge, particularly in healthcare facilities where waterborne infections pose significant risks. This study presents the implementation of the eBooster^TM electrochemical disinfection system, developed by Ecas4 Australia, as a maintenance-free solution for microbial control in hospital water supplies. Unlike previous electrochemical disinfection technologies, which suffered from scale buildup and required frequent maintenance, the eBooster^TM system utilizes periodic polarity reversal to prevent electrode fouling, enabling continuous operation without external intervention. The technology has been adopted by several regional hospitals in Queensland, Australia, and this paper focuses on Dalby Hospital, where two eBooster^TM systems were installed at water meters to provide residual disinfection in an in-line configuration. Performance data collected over nearly 2 years demonstrated consistent chlorine generation for microbial control with minimal energy consumption (less than 2 kWh/day). The system’s ability to adapt to fluctuating flow rates while maintaining consistent disinfectant levels highlights its reliability in real-world applications. This work emphasizes the potential of electrochemical disinfection as a sustainable alternative to chemical dosing in drinking water systems, offering a maintenance-free, cost-effective, and environmentally friendly solution for long-term microbial safety in healthcare and other critical settings. Full article

Electrochemical reduction is a promising strategy for the dechlorination of halogenated organic compounds, offering advantages such as enhanced electron transfer efficiency and increased hydrogen atom concentration. It has garnered significant attention for application in mitigating halogenated disinfection by-products (DBPs) in drinking water, owing to its high efficiency and simple operation. In this study, trichloroacetic acid (TCAA), a representative DBP, was selected as the target contaminant. A novel composite cathode comprising a metal–organic framework MIL-53(Fe)@C supported on an Nd magnet (MIL-53(Fe)@C-MAG) and its dechlorination performance for TCAA were systematically investigated. The innovative aspect of this study is the magnetic attachment of the MOF catalyst to the carbonized cathode surface treated through carbonization, which fundamentally differs from conventional solvent-based adhesion methods. Compared to the bare electrode, the MIL-53(Fe)@C-MAG achieved a TCAA removal efficiency exceeding 96.03% within 8 h of contact time. The structural characterization revealed that the α-Fe⁰ crystalline phase serves as the primary active center within the MIL-53(Fe)@C catalyst, facilitating efficient electron transfer and TCAA degradation. The scavenger experiments revealed that TCAA reduction involves a dual pathway: direct electron transfer and atomic hydrogen generation. The modified MIL-53(Fe)@C-MAG electrode exhibited robust electrolytic performance over a broad pH range of 3–7, with TCAA removal efficiency showing a positive correlation with current density within the range of 10–50 mA/cm². Furthermore, the electrode maintained exceptional stability, retaining more than 90% removal efficiency after five consecutive operational cycles. The versatility of the system was further validated by the rapid and efficient dechlorination of various chlorinated DBPs, demonstrating the broad applicability of the electrode. The innovative magnetic composite electrode demonstrates a significant advancement in electrochemical dechlorination technology, offering a reliable and efficient solution for the purification of drinking water contaminated with diverse halogenated DBPs. These results provide valuable insights into the development of electrolysis for dechlorination in water treatment applications. Full article

Electrochemical disinfection systems are gaining attention as potential solutions for reducing microbial contamination in drinking water distribution networks. While numerous recent studies suggest that these systems are easy to implement, real-world application reveals significant challenges. Many published works suffer from fundamental flaws, including inappropriate material selection, unrealistic operating conditions, and non-compliance with regulatory standards. This review critically examines studies published over the past 24 months, highlighting key issues that limit practical applicability. It discusses common pitfalls, such as the use of unstable or toxic electrode materials and the failure to provide residual disinfectant effects. Additionally, the review outlines essential characteristics for effective electrochemical disinfection systems, emphasizing compliance with health regulations, scalability to real-world conditions, and long-term operational stability. By identifying these gaps, this review article aims to guide future research toward more viable, safe, and sustainable electrochemical disinfection solutions for drinking water treatment. Full article

Chlorine plays an essential role in various industries, such as wastewater treatment, disinfection, plastics, and pharmaceuticals, contributing to a significant global demand. Traditional methods of chlorine production, including chemical reactions involving manganese dioxide, potassium chlorate, and potassium permanganate, as well as the electrolysis of saturated salt solutions, are associated with safety and efficiency concerns. This study introduces a novel approach for the photoelectrocatalytic production of chlorine gas through the oxidation of chloride ions in potassium chloride solutions using a dual semiconductor photoelectrode system composed of TiO₂ and Cu₂O. By harnessing solar energy, this system enables the concurrent, safe, and efficient production of both chlorine and hydrogen gases. The TiO₂ photoelectrode is employed for chlorine production, while Cu₂O is used for hydrogen generation. The dual photoelectrode system mimics the process of electrolytic seawater electrolysis, offering a promising alternative to conventional methods. Through linear sweep voltammetry, current–time tests, and electrochemical impedance spectroscopy, we demonstrate the effectiveness of this approach, supported by a detailed analysis of the energy band structure. Additionally, the material’s characteristics were verified using X-ray diffraction (XRD) and scanning electron microscopy (SEM). This work not only provides a safer and more efficient method for chlorine production but also highlights the potential of solar-powered photoelectrocatalysis in large-scale applications. These findings point toward a sustainable and environmentally friendly direction for chlorine production under simulated seawater conditions, with significant implications for renewable energy-driven industrial processes. Full article

The disinfection of drinking water is essential for eliminating pathogens and preventing waterborne diseases. However, this process generates various disinfection byproducts (DBPs), which toxicological research indicates can have detrimental effects on living organisms. Moreover, the safety of these DBPs has not been sufficiently assessed, underscoring the need for a comprehensive evaluation of their toxic effects and associated health risks. Compared to traditional methods for studying the toxicity of pollutants, emerging electrochemical sensing technologies offer advantages such as simplicity, speed, and sensitivity, presenting an effective means for toxicity research on pollutants. However, challenges remain in this field, including the need to improve electrode sensitivity and reduce electrode costs. In this study, a pencil graphite electrode (PGE) was modified with carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and nano-iron (III) oxide (α-Fe₂O₃) to fabricate a low-cost electrode with excellent electrocatalytic performance for cell-active substances. Subsequently, a novel cellular electrochemical sensor was constructed for the sensitive detection of the toxicity of three drinking water DBPs. The half inhibitory concentration (IC₅₀) values of 2-chlorophenylacetonitrile (2-CPAN), 3-chlorophenylacetonitrile (3-CPAN), and 4-chlorophenylacetonitrile (4-CPAN) for HepG2 cells were 660.69, 831.76, and 812.83 µM, respectively. This study provides technical support and scientific evidence for the toxicity detection and safety assessment of emerging contaminants. Full article

A sensitive and reliable electrochemical biosensor for the detection of benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC), the most commonly used disinfectant biocides in the agri-food industry, is described. Acetylcholinesterase from Drosophila melanogaster (DM AChE) and butyrylcholinesterase from horse serum (BChE) were immobilized by entrapment in a photocrosslinkable polymer on the surface of carbon screen-printed electrodes. Preliminary tests conducted in phosphate buffer showed limits of detection (LODs) of 0.26 µM for BAC using the BChE-based sensor and 0.04 µM for DDAC using the DM AChE sensor. These performances comply with the European regulation for dairy products, which sets a maximum allowable concentration of 0.28 µM for biocides. However, when tested directly in milk samples, a dramatic decrease in the sensitivity of both sensors towards BAC and DDAC biocides was reported. To overcome this problem, a simple liquid–liquid extraction was necessary prior to biosensor measurements, ensuring that the biosensors met European regulatory standards and provided an unbiased response. Full article

The elimination of pollutants in real water and wastewater is a challenge for the successful application of electrooxidation processes (EOPs). The presence of inorganic salts in the reaction medium is of great relevance during EOPs, with active participation in the electrochemical reactions. A revision of the reported devices used in the decontamination and disinfection of real wastewater demonstrated the main drawbacks of efficiently removing pollutants. However, the combination of photocatalytic processes with electrochemical technologies has been explored to improve overall efficiency and reduce energy consumption. A wide variety of materials, mainly metals, polymers, carbon and graphite derivatives, oxides, and MOFs, as well as their combinations, have been applied to electrodes and photoactive coatings. The deposition of the active layer has been enriched with novel designs, including porous hierarchical growth and 3D printing. The use of powerful characterization techniques allows for the study of the composition, structure, surface, and photo- and electrochemical performance of the fabricated electrodes. The simultaneous optimization of the operating conditions, parameters, and reactors must be specifically defined according to each water matrix. This approach will increase the efficiency of the whole process and contribute to cost savings. Economic contributions have been revised to calculate the cost of wastewater treatment. Full article

Triiodide salts are of interest for a variety of applications, including but not limited to electrochemical and photochemical devices, as antimicrobials and disinfectants, in supramolecular chemistry and crystal engineering, and in ionic liquids and deep eutectic solvents. Our work has focused on the design of salt–solvate cocrystals and deep eutectic solvents in which the triiodide anion interacts as a halogen bond acceptor with organoiodine molecules. To understand structure–property relationships in these hybrid materials, it is essential to have benchmark structural and physical data for the parent triiodide salt component. Herein, we report the structure and thermal properties of eight new triiodide salts, three of which exhibit polymorphism: tetrapentylammonium triiodide (1a and 1b), tetrahexylammonium triiodide (2), trimethylphenylammonium triiodide (3), trimethylbenzylammonium triiodide (4), triethylbenzylammonium triiodide (5), tri-n-butylbenzylammonium triiodide (6), 3-methylbenzothizolium triiodide (7a and 7b), and 2-chloro-1-methylpyridinium triiodide (8a and 8b). The structural features of the triiodide anion, Raman spectroscopic analysis, and melting and thermal decomposition behavior of the salts, as well as a computational analysis of the polymorphs, are discussed. The polymorphic pairs here are distinguished by symmetric versus asymmetric triiodide anions, as well as different packing patterns. Computational analyses revealed more subtle differences in their isosurface plots. Importantly, this study provides reference data for these new triiodide salts for comparison to hybrid cocrystals and deep eutectic solvents formed from their combination with various organoiodines. Full article

The coagulation and flocculation properties of chitosan, an organic biopolymer derived from chitin, have been researched as an alternative to synthetic polymers and inorganic metal salt coagulants currently used in water and wastewater treatment. In an effort to encourage further research into the practical uses of chitosan as green chemistry in water and wastewater treatment and to promote the efficacious removal of microbial contaminants in drinking and wastewater, we have summarized the current state of research pertaining to the treatment of microorganisms in water and wastewater. A search of PubMed revealed 720 possible titles and abstracts, of which 44 full-text articles were identified as matching the eligibility criteria for inclusion in this systematic review. Results are presented based on the type of water matrix treated (i.e., drinking water, wastewater, and recreational waters) and a summary table providing details on the types and forms of chitosan utilized and the treatment mechanisms and processes described in the study. We find chitosan to be an effective coagulant, flocculant, and adsorbent for removing microbes from water and wastewater; some modified forms of chitosan can inactivate microbes and achieve disinfection, such as those containing metals like silver and antimicrobial chemicals like quaternary ammonium compounds or other strong oxidants, and use with filtration or electrochemical processes can achieve extensive reductions in microbes to meet performance targets of the World Health Organization. Full article

Carbon nitrides can form coordination compounds or metallic oxides in the presence of transition metals, depending on the reaction conditions. By adjusting the pH to basic levels for mild synthesis with metals, composites like g-C₃N₄-M(OH)_x (where M represents metals) were obtained for nickel (II) and manganese (II), while copper (II) yielded coordination compounds such as Cu-g-C₃N₄. These materials underwent spectroscopic and electrochemical characterization, revealing their photocatalytic potential to generate superoxide anion radicals—a feature consistent across all metals. Notably, the copper coordination compound also produced significant hydroxyl radicals. Leveraging this catalytic advantage, with band gap energy in the visible region, all compounds were activated to disinfect E. coli bacteria, achieving total disinfection with Cu-g-C₃N₄. The textural properties influence the catalytic performance, with copper’s stabilization as a coordination compound enabling more efficient activity compared to the other metals. Additionally, the determination of radicals generated under light in the presence of dicloxacillin supported the proposed mechanism and highlighted the potential for degrading organic molecules with this new material, alongside its disinfectant properties. Full article

Clostridioides difficile is a widely distributed anaerobic pathogen. C. difficile infection is a serious problem in healthcare. Its biofilms have been found to exhibit biocorrosivity, albeit very little, but sufficient for it to correlate with biofilm growth/health. This work demonstrated the use of a disposable electrochemical biofilm test kit using two solid-state electrodes (a 304 stainless steel working electrode, and a graphite counter electrode, which also served as the reference electrode) in a 10 mL serum vial. It was found that the C. difficile 630∆erm Adp-4 mutant had a minimum inhibitory concentration (MIC) for vancomycin twice that of the 630∆erm wild type strain in biofilm prevention (2 ppm vs. 1 ppm by mass) on 304 stainless steel. Glutaraldehyde, a commonly used hospital disinfectant, was found ineffective at 2% (w/w) for the prevention of C. difficile 630∆erm wild type biofilm formation, while tetrakis(hydroxymethyl)phosphonium sulfate (THPS) disinfectant was very effective at 100 ppm for both biofilm prevention and biofilm killing. These antimicrobial efficacy data were consistent with sessile cell count and biofilm imaging results. Furthermore, the test kit provided additional transient biocide treatment information. It showed that vancomycin killed C. difficile 630∆erm wild type biofilms in 2 d, while THPS only required minutes. Full article