Active Chlorine Concentration Research Articles

Transformation behavior of the ultraviolet absorbent 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) in polyethylene plastic under chlorination

In plastic, a 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) ultraviolet light absorber is a common additive. When using sodium hypochlorite (NaClO) to disinfect plastic, UV328 may react with NaClO. For this work, we investigated the transformation behavior of UV328 in polyethylene (PE) plastic by NaClO. The reaction rate increased with the initial free active chlorine (OCl−) concentration and the decrease of the initial UV328 concentration. At room temperature (25 °C) to lower temperatures (0 °C), OCl− could transform UV328, and the reaction activation energy was fitted as 31.10 kJ/mol. Replacement of the plastic carrier (change to polypropylene) had no effect on the reaction process. A total of 12 intermediates were identified, and calculations based on density functional theory (DFT) were used to assist in rationalizing the product structure. Chlorination, hydroxylation, coupling, and bond cleavage were speculated as the main transformation pathways. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were the only two measured disinfection by-products in the system, and their concentration were 18.33 and 18.19 μg/g, respectively. The toxicity prediction by Toxicity Estimation Software Tool (T.E.S.T) illustrated that the toxicity of the transformation products was higher overall than that of UV328 during the reaction. This work can help to deepen the understanding of the transformation behavior of UV328 in PE plastic in NaClO solution.

Formation of biosafety and greening of the production environment of food production with application of anolyte

Introduction: Electrochemically activated aqueous solutions are widely used in medical institutions, animal husbandry, as well as in large food processing facilities. This work presents a literature review on the use of electrochemically activated solutions in the food industry. These solutions can be used as a safe means for processing food raw materials, equipment, food containers, and surfaces of foodservice facilities. The question of using activated aqueous solutions in relation to foodservice establishments is not fully explored in the scientific literature.Purpose: The aim of the research is to study the possibility of using electrochemically activated aqueous solutions as safe and environmentally friendly means for treating objects in the production environment to eliminate the risk of contamination by microorganisms.Materials and Methods: Surfaces of the production environment were selected as the objects of study, including a table, scales, a knife, a slicer, and a gastronorm container. Sweet pepper fruits of the "Avangard" variety were chosen as non-heat-treated food products. An electrochemically activated aqueous solution of chlorine dioxide and hydrogen peroxide compounds with a concentration of active substances of 0.5 ± 0.05 g/L (Anolyte ANK-SUPER) was chosen as the treatment agent. Microbiological studies were conducted using XLD Agar medium and petrifilms. To assess the effectiveness of treatment, microbiological studies were conducted with the determination of Coliform Bacteria (BGKP) and Mesophilic Aerobic and Facultative Anaerobic Microorganisms (KMAFAnM). To achieve acceptable microorganism counts for counting purposes, the tenfold dilution method was used. The residual active chlorine concentration was determined using the iodometric method to determine the actual concentrations of working solutions.Results: The use of undiluted disinfectant with a concentration of 0.5 ± 0.05 g/L confirmed the effectiveness of electrochemically activated solutions against Coliform Bacteria (BGKP), with a significant reduction in the content of Mesophilic Aerobic and Facultative Anaerobic Microorganisms (KMAFAnM) compared to control samples. However, the results of the experiments suggest that parameter selection is required, specifically the concentration of the disinfectant and the duration of treatment depending on the object. The data obtained from preliminary experiments characterize the potential use of reduced concentrations of the working solution (no less than 0.05 ± 0.005 g/L of active chlorine), but do not confirm the possibility of full-scale application of the used concentrations due to the lack of quantitative data on the degree of contamination of the initial surfaces. The possibility of using the solutions as a single agent for treating both working surfaces and fruit and vegetable products has been demonstrated.Conclusion: As a result of the conducted research, the effectiveness of disinfectants based on electrochemically activated solutions against Escherichia coli bacteria (BGKP) and the reduction of Mesophilic Aerobic and Facultative Anaerobic Microorganisms (KMAFAnM) has been confirmed. In addition, among the possible prospects for research, determining the minimum concentrations and contact times for achieving stable disinfecting effects can be mentioned. The results obtained showed that the use of electrochemically activated solutions ensured the biological safety of treated production objects and surfaces of thermally untreated food products. An alternative method of using electrochemically activated solutions as a universal environmentally friendly agent has been proposed. Thus, in foodservice establishments, an effective "green" technology based on electrochemically activated solutions can be implemented.

Durable and rechargeable antimicrobial cotton driven by enhanced UV stability and real-time detection of biocidal factors

In this study, graphene oxide/N-halamine nanocomposite was synthesized through Pickering miniemulsion polymerization, which was then coated on cotton surface. The modified cotton exhibited excellent superhydrophobicity, which could effectively prevent microbial infestation and reduce the probability of hydrolysis of active chlorine, with virtually no active chlorine released in water after 72 h. Deposition of reduced graphene oxide nanosheets endowed cotton with ultraviolet-blocking properties, attributing to enhanced UV adsorption and long UV paths. Moreover, encapsulation of polymeric N-halamine resulted in improved UV stability, thus extending the life of N-halamine-based agents. After 24 h of irradiation, 85 % of original biocidal component (active chlorine content) was retained, and approximately 97 % of initial chlorine could be regenerated. Modified cotton has been proven to be an effective oxidizing material against organic pollutants and a potential antimicrobial substance. Inoculated bacteria were completely killed after 1 and 10 min of contact time, respectively. An innovative and simple scheme for determination of active chlorine content was also devised, and real-time inspection of bactericidal activity could be achieved to assure antimicrobial sustainability. Moreover, this method could be utilized to evaluate hazard classification of microbial contamination in different locations, thus broadening the application scope of N-halamine-based cotton fabrics.

INFLUENCE OF ELECTROCHEMICALLY ACTIVATED SOLUTIONS ON THE FATTY ACID PROFILE OF FOOD SYSTEMS

The emergence of new types and methods of food processing requires studying the impact on the compo-nents of food systems. Fish products are an important part of the human diet, but as a result of storage, their quality and safety indicators are reduced. An effective way to ensure the biological safety of fish raw materials is the use of electrochemically activated solutions (ECAS) obtained by high-voltage diaphragm electrolysis. The aim of the study was to study the effect of various concentrations of ECAS on the fatty acid profile of food systems using the example of fish oil from Atlantic salmon (Salmo salar) fillet during the shelf life. In the experiments, a ready-made ECAS with an active chlorine concentration (hereinafter Cach) of 500 mg/l (0.05%) was used, from which working ECAS were prepared with a dilution of 50% and 15%, which corresponds to Cach – 250 mg/l (0.025%) and Cach – 75 mg / l (0.0075%). The concentration of ECAS was selected experimentally in order to determine the optimal concentration at which the de-struction of fatty acids (hereinafter FA) of the studied samples did not occur. The determination was car-ried out by gas chromatography using a Crystal-2000M chromatograph. Comparison was made with con-trol samples. Identification of the peaks of FA methyl esters of the tested samples made it possible to de-termine the recommended working concentration of active chlorine ECAS equal to 75 mg/l, at which the content of polyunsaturated fatty acids does not statistically decrease. The research results can be used to ensure the quality and biological safety of fish fillets, taking into account the specific effects of ECAS on individual components of food systems.

Безопасность использования в практике дезинфицирующих средств на основе гипохлорита натрия

The parameters of toxicometry of disinfectants based on sodium hypochlorite obtained by chlorination of an aqueous solution of caustic soda (31 agents) and by electrochemical method – 10 anoliths were established. Based on the determination of the chlorine content in the air, recommendations are given for the safe use of these disinfectants: for surface treatment by wiping and disinfection of air and surfaces by aerosol spraying using a special device – an aerosol generator that provides dispersion of aerosol particles of 5–50 microns. A working solution of sodium hypochlorite with an active chlorine content of 0.015?% is recommended for use by wiping in the presence of people. Keywords: disinfectants, sodium hypochlorite, anolytes, toxicity, irritant effect, inhalation hazard, aerosol, laboratory animals.

Durable and biocompatible antibacterial N-halamine membranes based on cellulose carbamate

Increasing attention had been paid to the antibacterial and safety properties of membrane materials. The cellulose carbamate membrane (RCCM) without antibacterial properties would limit its applications in the food packaging industry. Herein, the antibacterial N-halamine regenerated cellulose carbamate membrane (RCCM-Cl) was manufactured by sodium hypochlorite solution treating the inherent amide of RCCM. The chemistry and mechanics properties of RCCM and RCCM-Cl were investigated. The antibacterial properties, cell compatibility, rechargeability and durability stability of RCCM-Cl were evaluated. Results demonstrated that the functional RCCM-Cl exhibits remarkable antibacterial activity which could sterilize Escherichia coli and Staphylococcus aureus within 1 min in the first contact period. The breaking strength, elongation at breaking, and transparency of RCCM-Cl retained 148.6 MPa, 8.1%, and 94%, respectively. In addition, antibacterial RCCM-Cl with active chlorine content exhibits excellent cell compatibility, regenerability, storage stability and stability in water.

Monitoring of On-Site generated Hypochlorite for Water Disinfection

The aim of this study was to better evaluate the impact of on-site electro-generated hypochlorite for water disinfection. For this venture, the daily variability of hypochlorite-generating systems and their performance to produce low disinfection by-products during the formation of hypochlorite were observed. Seven on-site electro-generated hypochlorite installations, were selected at different swimming pool facilities in Switzerland. Active chlorine (AC), the two disinfection by-products chlorate (ClO3-) and perchlorate (ClO4-), and the pH were monitored over several hours. All monitored installations produced significant concentrations of chlorate, related to the measured active chlorine concentration. The median chlorate concentrations ranged between 1.4 to 76.9 µg ClO3-/mg AC during daily monitoring. Perchlorates have been detected only in the installations of one brand that generated concentrations up to 34.9 µg ClO4-/mg AC. For all installations, pH was lower than expected with a median pH of 9.6. Some samples presented even surprisingly acidic pH leading to possible sample degradation. This study clearly shows the weakness of a one-shot sampling to evaluate the quality of on-site electro-generated hypochlorite systems, due to high daily process variations. Additionally, the evaluation of the influence of three process parameters has pointed out that including chlorate aspects during the optimisation stage of on-site generated hypochlorite may significantly reduce chlorate contamination during water disinfection.

Synthetic polyurethane nanofibrous membrane with sustained rechargeability for integrated air cleaning

Health problems caused by airborne particulate matter (PM) and bacteria have placed a severe burden on public health. At present, most personal protective equipment focused on PM filtration but ignored the threat from pathogens like bacteria in the air. Moreover, the disposable protective items such as masks used in large quantities have caused great pollution issues. Hence, in this study, a fresh polyurethane nanofibrous membrane (named as PU/PIU-Cl) was synthesized with imidazolidinyl urea groups as block components for enhanced biocidal effect which not only has extremely high filtration efficiency (up to 99.92%) against particulate pollutants, but also excellent intrinsic antibacterial ability (>99%) and safety, indicating its remarkable performance for integrated air pollution control. Furthermore, the antibacterial ability of the membrane can be facilely regenerated by re-chlorination, and the active chlorine content of PU/PIU-Cl membrane through halogenation hardly decreased after five cycles. Therefore, the PU/PIU-Cl nanofibrous membrane can not only be used as protective equipment, such as masks with sterilization function, but also can effectively alleviate the pollution problem of disposable protective products. • Imidazolidinyl urea groups are employed as block components of polyurethane. • PU/PIU-Cl exhibits intrinsic antibacterial function and high filtration efficiency. • PU/PIU-Cl is low cytotoxic, low cost and reusable, and shows great potential in PPE.

Long-lasting renewable antibacterial graphene/N-halamine-coated cotton fabrics benefitting from enhanced UV stability and quantitative tracking of bactericidal factors

In this study, anionic GO aqueous dispersion and cationic QAS aqueous solution with specific concentrations were applied for the fabrication of modified cotton fabrics (MCFs) through the layer-by-layer self-assembly method. The chlorinated cotton fabrics with optimized protocol possessed excellent ultraviolet-blocking properties, with a UPF value of 323.08. Moreover, graphene greatly improved the UV stability of N-halamine, which could also be proved in the UV aging test of MCFs. In addition, the modification procedure also endowed cotton fabrics with superhydrophobic properties, thus broadening the application range of cotton fabric. The obtained GQC10 possessed excellent antibacterial activity, with all inoculated S. aureus and E. coli O157:H7 being completely killed within 5 min and 1 min of contact time, respectively. Indicated by the quantitative function relation between the active chlorine content (ACC) and the surface sheet resistance (SSR) of the MCFs, a novel and simple method for the determination of ACC was established. This method could be used to monitor the antimicrobial efficacy to ensure its sustainability. Furthermore, according to the variation frequency of SSR, the risk level of bacterial hazards in different places could be evaluated, thus broadening the application range of N-halamine-based antibacterial cotton fabrics.

Polyvinylidene fluoride multi-scale nanofibrous membrane modified using N-halamine with high filtration efficiency and durable antibacterial properties for air filtration

HypothesisParticulate matter (PM) pollution and the coronavirus (COVID-19) pandemic have increased demand for protective masks. However, typical protective masks only intercept particles and produce peculiar odors if worn for extended periods owing to bacterial growth. Therefore, new protective materials with good filtration and antibacterial capabilities are required. ExperimentsIn this study, we prepared multi-scale polyvinylidene fluoride (PVDF) nanofibrous membranes for efficient filtration and durable antibacterial properties via N-halamine modification. FindingsThe N-halamine-modified nanofibrous membrane (PVDF-PAA-TMP-Cl) had sufficient active chlorine content (800 ppm), and the tensile stress and strain were improved compared with the original membrane, from 6.282 to 9.435 MPa and from 51.3 % to 56.4 %, respectively. To further improve the interception efficiency, ultrafine nanofibers (20–35 nm) were spun on PVDF-PAA-TMP-Cl nanofibrous membranes, and multi-scale PVDF-PAA-TMP-Cl nanofibrous membranes were prepared. These membranes exhibited good PM0.3 interception (99.93 %), low air resistance (79 Pa), promising long-term PM2.5 purification ability, and high bactericidal efficiency (>98 %). After ten chlorination cycles, the antibacterial efficiency against Escherichia coli and Staphylococcus aureus exceeded 90 %; hence, the material demonstrated highly efficient filtration and repeatable antibacterial properties. The results of this study have implications for the development of air and water filtration systems and multi-functional protective materials.

STUDY OF THE ANTIMICROBIAL ACTION OF «SANATION +» FOR THE PREVENTION AND TREATMENT OF ACUTE RESPIRATORY DISEASES

State of the problem. Given the extreme threat of the Covid-19 pandemic in Ukraine to combat it, it is now important to develop and use effective antimicrobials, including disinfectants to disrupt the transmission mechanisms of the pathogen. Promising for use are the means obtained by electrolysis. The aim of the work. The study was to determine the specific activity and safety of «Sanation+», the effectiveness of disinfection of the mucous membranes of the upper respiratory tract of volunteers and evaluate the effectiveness of the tool for the treatment of patients with Сovid-19 and for the prevention of respiratory diseases. Materials and methods. The study used a medical device «Sanation+», which contains hydrochloric acid, highly active oxygen compounds of chlorine, free radicals of chlorine and oxygen, NaCl (mass concentration of active chlorine – 0.035%). The antimicrobial action of the product according to the Order of the Ministry of Health of Ukraine N 2024, dated September 3, 2020. To study the effectiveness of decontamination of the upper respiratory tract of volunteers with the «Sanation+» used devices for the formation of aerosols: – nebulizer «Nano Mist Sprayer» (China), which sprays the drug with a volume of 1.25 - 1.45 cm3 for 60 seconds. The distance from the spray to the mucous membranes was 5 - 10 cm; – compressor inhaler, model CN-123 (Japan). Results. It was found that the tool «Sanation+» showed high virilicidel, bactericidal and yeastic activity under exposure for 30 and 60 sec. for Escherichia coli K12 NCTC 10538 lg R > 5.42, for Pseudomonas aeruginosa lg R > 5.37; for Staphylococcus aureus lg R > 5.34; for Candida albicans lg R > 4.31. Remediation + when used undiluted and exposed for 30 sec is an effective tool for disinfection from macro- and microviruses, as evidenced by the high logarithms of the reduction of bacteriophages: T2 – > 5.08 lg, MS2 – > 5.12 lg, indicating the virucidal action of the tool against enveloped and non-enveloped viruses. As a result of the application of «Sanation+» through the nebulizer «Nano Mist Sprayer» there was a significant reduction in the number of microorganisms on the mucosal surface of nasal volunteers: after 5 min the drug decreased by 4.22 lg, on the throat mucosa – by 4.14 lg. The use of the drug through an inhaler helped to reduce the number of microorganisms on the surface of the mucous membranes of both the nose and throat. The most effective duration of action is 5 min (reduction factor: for the nasal mucosa RF = 4.23, for the throat mucosa RF = 4.78). Conclusions. High efficiency of means for rehabilitation of respiratory tracts «Sanation+», for application in complex therapy at treatment of a coronavirus disease at 55 patients is established. The use of «Sanation+» for the prevention of Covid-19 among health care workers in medical institutions of the disease was not detected. Key words: remedy «Sanation+», bactericidal, virucidal, volunteers, patients, Сovid-19.

Physicochemical properties of potato starches oxidised by different concentrations of sodium hypochlorite, and their application in yogurt

Potato starch was modified by oxidation with different concentrations of active chlorine (0.5, 1.0, 2.0, 3.0, and 4.0%); and the physicochemical properties of the oxidised potato starch samples and the use of these starches in set yogurt were investigated as a function of their degree of oxidation. The carboxyl content, carbonyl content, and solubility of the oxidised starches increased with increasing sodium hypochlorite concentrations, while the swelling power decreased. Scanning electron microscopy showed that oxidation caused cracks or pores on the surfaces of the starch granules, and these morphological changes were enhanced by increased oxidant concentrations. Analysis with a Rapid Visco Analyser showed that high degrees of oxidation could improve the starch thermodynamic stability and resistance to retrogradation. Set yogurts made with oxidised potato starches had higher water-holding capacities, higher apparent viscosities, and better sensory qualities than those prepared with native starch.

A study on the antibacterial efficacy of Halohydantoin-containing foams

Heterocyclic N-halamine compounds such as 1-monochloro-5,5-dimethylhydantoin (MCDMH) and 1,3-dichlor-5,5-dimethylhydantoin (DCDMH) show antimicrobial activity and odour control. Both MCDMH and DCDMH stabilise and display oxidative chlorine (Cl+1) and, in aqueous environments, generate hypochlorous acid (HOCl). It is well known that HOCl, produced by neutrophils as part of the respiratory immune response, is used as a defence mechanism against foreign bodies. This study aimed to investigate the antibacterial efficacy of proprietary foaming formulations containing mixtures of MCDMH and DCDMH provided by MedeSol Inc., as a potential delivery mechanism for HOCl. The efficacy of the foams containing active chlorine concentrations of 350 ppm and 1050 ppm was tested against single and multi-species bacterial mixtures of S. aureus, P. aeruginosa, E. coli, E. faecalisand K. pneumoniae. Cellulose filters were contaminated with single/multispecies bacterial suspensions and left to air-dry; the two foam concentrations were applied for 15, 30 and 60 seconds at a time. Samples were taken and the total viable count method was employed to determine antibacterial efficacy of the foams. Following the use of both foam concentrations, no colonies were recovered at any time-points in both single and multi-species experiments. In contrast, the negative controls where the foam application was omitted, resulted in high numbers of bacterial colonies. MCDMH-containing foams have very strong antibacterial potential as a result of active chlorine release. Further studies are needed to determine concentration dependence and use in other applications including hand sanitation.

Morphology and functionality of dry heat‐treated and oxidized quinoa starches

Starch from quinoa was isolated by alkaline steeping method and isolated starch was modified by oxidation (@1%, 1.5% and 2% w/v active chlorine) and dry heat treatment (@ 150 and 200°C for 2 h). Native and treated starches were analyzed for physicochemical, functional and morphological characteristics. The yield of quinoa starch was 54.2% with 89.3% purity. The shape of starch granules was polygonal and irregular with an averagediameter of 1.13 μm. Starch modified by dry heat treatment enhanced solubility, water-binding capacity, and transmittance in comparison with native starch. The peak, trough and final viscosity were higher in the case of dry heat-treated starches at a lower temperature than samples of native starch as well as dry heat-treated at a higher temperature. Oxidized starches showed higher values of whiteness, breakdown and setback viscosity. Modification treatments lowered the pasting temperature and swelling power of quinoa starch. Novelty impact statement Studies on quinoa starch modification by dry heat treatment and oxidation are rare in literature and present work represents the effect of these treatments on quino starch properties. Data revealed that active chlorine concentration and heating conditions (time and temperature) during modification treatments altered quinoa starch functionality uniquely. The results offer a useful base for modification of quinoa starch by oxidation and dry heat treatment at different conditions to enhance its applicability in different industries.

Modification of electrospun PI membranes with active chlorine for antimicrobial skin patches applications

Atopic dermatitis (AD) is a common andcomplex disorder caused by many inherently intractable factors. One of the symptoms is an increased amount of Staphylococcus aureus on the skin surface. These bacteria trigger, accelerate, and exacerbate AD. In order to reduce inflammation, we designed antimicrobial patches, which inhibit bacterial growth. Using electrospinning, we produced polyimide (PI) nanofibers collected in the form of porous membranes. These PI membranes were modified with sodium hypochlorite (NaOCl). The active chlorine content was confirmed with scanning electron microscopy (SEM) with secondary electrons (SE) mode, backscattered electrons (BSE) mode, and energy-dispersive X-ray (EDX) spectroscopy, with Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Moreover, we evaluated the wettability and zeta potential of the patches. Finally, we performed an antimicrobial efficacy assay against the Gram-positive model organism S. aureus and the Gram-negative model, Escherichia coli. We observed that the chlorinated PI patches demonstrate effective bacterial killing, making them excellent material for antimicrobial skin patches applications.

Impact of nano-ZnO consolidated poly (ether ether sulfone) nano filtration membrane for evacuation of hazardous metal particles

Industrial wastewater contains heavy metals, colors, dyes, cyanides, and natural manufactured compounds are expanding around the world. It prompts extreme water shortage just as water quality issues. With enhancing worldwide interest for clean and reestablish water for human utilization. Wastewater treatment with membrane innovation is arising as a main cycle to address the issues. In this current work, we have found the expulsion of dangerous metal particles utilizing a nano-ZnO (0.5 wt%) incorporated poly (ether ether sulfone) (PEES) nanofiltration membrane. The created membranes were reviewed by ATR-FTIR, AFM, SEM investigations, XRD, contact angle estimation, mechanical properties, pure water flux, porosity and molecular weight cut-off, arsenic, fluoride, and nitrate rejection studies were illustrated. Because of the hydrophilic nature of ZnO, the resultant membranes had better hydrophilicity than PEES membranes based on porosity, water content, surface chemistry, membrane morphology, and contact angle data. The Nano-ZnO incorporated membrane demonstrated a superior quality execution contrasted with neat PEES membrane. We discovered that the rejection of As(III) and As (V) were > 85% and > 98% separately, and an expanded permeability of 559.28 ± 2 Lm−2 h−1 and 297.95 ± 2 Lm−2 h−1 individually was seen at pH 10. Fluoride and nitrate particles additionally indicated the most extreme expulsion efficiencies were > 89% and > 75% separately. The prepared membrane samples were incubated in water (40 °C) and sodium hypochlorite solution (active chlorine concentration 400 mg/L) for up to 10 days to determine the stability of polymer membrane matrix. The general outcomes inferred that the nano-ZnO incorporated PEES membrane gave remarkable result to eliminate dangerous metal ions with moderate permeability.

Optimised preparation and characterisation of lotus root starch oxidised with sodium hypochlorite (NaOCl) using response surface methodology

In this paper, response surface methodology (RSM) was used to study the optimised process conditions of lotus root starches modified by treatment with sodium hypochlorite (NaOCl). Based on the Box-Behnken design, quadratic models were developed to correlate the reaction variables. Analysis of variance (ANOVA) revealed that the active chlorine content was the most significant variable for the response. Under the experimental conditions in this paper, the calculated carboxyl content (CN<sub>COOH</sub>) of obtained samples was approximately 0.98% ± 0.02% (n = 5). The spectra of Fourier transform infrared (FTIR) spectroscopy displayed that the formation of carboxyl groups successfully occurred on the oxidised lotus root starches. Scanning electron microscope (SEM) analysis showed that the oxidised lotus root starch (CN<sub>COOH</sub>, 0.98%) granules were mostly spherical in shape and their surfaces were slightly rougher than those of native lotus root starch. This work may contribute to providing technical support and theoretical guidance for the production of oxidised lotus root starches using NaOCl as an oxidising agent.

Biofouling protection for marine optical windows by electrolysis of seawater to generate chlorine using a novel Co-based catalyst electrode

Ocean optical windows suffer serious biofouling, and electrochemical chlorination has been proposed as an innovative protective way. In this work, Co-based catalysts consisting of Co and Co(OH)2 were electrodeposited on Ti foils via the facile chronoamperometry technique, and their catalytic activity towards chlorine evolution reaction (CER) was investigated. The results showed the morphology and activity of catalysts varied with electrodeposition potential and time, and Ti foils electrodeposited at −1.5 V (vs. SCE) for 400 s held the highest CER catalytic activity. Co and Co(OH)2 transferred into Co3O4 at potentials more negative than CER, and it was Co3O4 that behaved as the catalyst. The CER selectivity of Co-based catalysts (–1.5 V, 400 s) was higher than 80% at current densities of 1–20 mA/cm2, and they also gave good stability. The bactericidal ratio of active chlorine concentration produced by chronoamperometry on Ti foils modified with catalysts towards Pseudomonas aeruginosa and Staphylococcus aureus was nearly 100% after 50 min of electrolysis. Furthermore, good antifouling of optical lens in seawater was achieved by a designed electrochemical chlorination accessory equipped with the as-prepared catalyst electrode. This work sheds light on the application of Co-based catalysts in antifouling of optical windows by electrochemical chlorination.

ЭФФЕКТИВНОСТЬ ПРОФИЛАКТИЧЕСКОЙ АЭРОЗОЛЬНОЙ ДЕЗИНФЕКЦИИ ПОМЕЩЕНИЙ АНОЛИТОМ НЕЙТРАЛЬНЫМ

The effectiveness of prophylactic aerosol disinfection with neutral anolyte studied in the infectious zones of the laboratory premises, which works with opportunistic microorganisms and pathogenic biological agents. Electrochemically activated chlorine­containing disinfectant “Anolyte neutral” with pH 7.2, redox potential + 880 mV and active chlorine content 200 mg/dm3 is highly effective when wiping surfaces in rooms with high microbial contamination and in aerosol volumetric and directed air disinfection. Minimal damage is caused to the processed objects. Aerosol volumetric disinfection of air with a «dry» fog using a cold fog generator leads to a significant decrease in microorganisms in the air by 91.1–94.7 % and is not inferior to ultraviolet radiation in terms of disinfection efficiency (90.7–91.1 %). During aerosol volumetric air treatment, harmful effects on personnel are prevented, objects in the room are not damaged, and bactericidal ultraviolet lamps are not needed. Aerosol directed disinfection of surfaces with a “moistened” fog using a cold fog generator completely destroys microorganisms on smooth accessible surfaces and is not inferior to wiping in terms of disinfection efficiency. Aerosol directed disinfection of hard­to­get rough surfaces with a “moist” fog leads to a decrease in bacterial contamination by 97.9–98.9 % and even exceeds the efficiency of wiping (95.8–96.1 %). With aerosol directed treatment, hard­to­get surfaces are effectively disinfected, disinfectant consumption is reduced, labor costs for cleaning and additional equipment are reduced by 3–4 times, there is no need to use ladders for processing of lamps, ceilings, ventilation grilles and moving equipment for processing hard­to­get places. For daily and general cleaning in healthcare organizations, aerosol volumetric air treatment and aerosol directed surface treatment with neutral anolyte can be recommended.

STUDY OF THE MORPHOSTOCHEM-ICAL STRUCTURE (CYTOMORPHOLOGY) OF CARNIVORE HELMINTH EGGS WITH THE PUR-POSE OF INCREASING THE EFFICIENCY OF THE EXTERNAL ENVIRONMENT

Sanitary significant types of helminths of domestic carnivores have a complex morphobiochemical structure that does not allow most chemical compounds to penetrate into the egg. The complete absence of disinfection proper-ties was established with respect to eggs of Toxocara canis and Taenia spp. preparations belonging to the group of oxidants (hydrogen peroxide and potassium permanganate 1–30 %), alkalis (sodium hydroxide 1–3 %). The absence of ovocidal properties in relation to toxocar eggs is also characterized by sodium hypochlorite obtained by the electro-chemical method, with an active chlorine concentration of less than 7 mg/l. A decrease in the humidity of the environ-ment due to sanitary products on a mineral basis to 40.0 % led to the cessation of the development of toxocara eggs and their 100% death within 7 days. With soil moisture below 8.0 %, after 48 hours, the development of irreversible changes in the morphological structure of 100 % of the eggs was noted.