Hypochlorite In Water Research Articles

Efficacy of Virucidal Treatments against Poliovirus Type 1 Deposited on Stainless-Steel Carriers.

Safe containment of infectious poliovirus (PV) within Poliovirus-Essential Facilities (PEFs) will require the implementation of reliable PV-inactivation approaches for decontaminating work surfaces. Such approaches should be demonstrated empirically to display adequate efficacy at the use temperature, and the contact times required should be characterized to ensure efficacy. Such efficacy is judged by the ability of the inactivation approach to completely inactivate any PV deposited, with the demonstrated total log10 reduction in PV titer being as high as empirically achievable. We screened several approaches for their efficacy in inactivating wild-type PV type 1 Chat strain experimentally deposited on stainless-steel carriers at room temperature. On the basis of the results, we selected two approaches (5000 ppm sodium hypochlorite in water and 95% v/v ethanol in water) for further characterization for repeatability of efficacy (log10 reduction in PV titer) and time kinetics of inactivation. We now report that both PV-inactivation approaches, which should be readily available to all PEF laboratories globally, fulfill the expectations expressed above, with 5000 ppm sodium hypochlorite reproducibly causing ≥5.38 log10 inactivation and 95% ethanol reproducibly causing ≥4.46 log10 inactivation of PV on stainless-steel surfaces within a 5 min contact time at room temperature.

Bithiophene-benzothiazole fluorescent sensor for detecting hypochlorite in water, bio-fluids and bioimaging in living cells, plants and zebrafish

Rationally designed and effectively synthesized D-π-A chemosensor DTA containing bithiophene fluorophore by using bithiophene aldehyde and benzothiazole salt and serves as highly specific chemosensor for colorimetric/fluorimetric turn-on detection of hypochlorite (ClO−) in ∼100 % aqueous media. DTA has obvious advantages of high specificity, short response time (8 s), broad pH working scope, ultra-sensitivity with low detection limit (5.3 nM), good bio-compatibility and permeability. The responding mechanism of DTA toward ClO− was investigated by 1H NMR, FTIR, HRMS, optical spectra and DFT calculations. Interestingly, DTA coated silica-gel, cotton buds, and filter-paper test strips were developed for qualitative and quantitative visual detection of ClO− in real-time. Notably, DTA was utilized to quantitatively detect ClO− in real-water and bio-fluids. Moreover, DTA was also applied to bioimage ClO− in live-cells, zebrafish and plant kingdoms, highlighting its broad application potentials. The simple structure and versatility of the DTA provides a convenient approach for developing multi-functional sensors and expanding its broader application fields.

Detection of environmentally hazardous hypochlorite in pure water with a novel fluorescent chemosensor: Application to water samples, commercial disinfectants, test strips, and zebrafish

With the increasing use of chlorinated disinfectants or bleaches such as sodium hypochlorite in the coronavirus disease 2019 (COVID-19) pandemic, the effectual detection of toxic hypochlorite is very important. In this study, a novel hydrazide-based fluorescence chemosensor DHT-Cl ((E)-2-(2-(3,5-dichloro-2-hydroxybenzylidene)hydrazinyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride) was synthesized. DHT-Cl could selectively detect environmentally hazardous hypochlorite in pure water through a fluorescence turn-off process. The detection limit for hypochlorite was determined to be 0.57 μM. DHT-Cl can monitor hypochlorite with little interference even in the presence of other analytes. Practically, DHT-Cl detected hypochlorite in water samples, commercial disinfectants, test strips, and living zebrafish. The hypochlorite detection mechanism through cleavage of the CN bond was illustrated by 1H NMR spectroscopy titration, ESI-mass spectrometry and quantum calculations.

Methyl position affect the fluorescence performance of HBT derivatives for the detection of hypochlorite under alkaline condition

Five fluorescent derivatives of hydroxyphenyl-benzothiazole (HBT) with different methyl positions at the hydroxyphenyl group were synthesized with good yield. Their reactivity and fluorescent response to hypochlorite were carefully studied. It was found that the HBT derivatives with meta-methyl (3-HBT or 5-HBT) showed the highest reactivity to hypochlorite under basic conditions, accompanied by the most efficient fluorescence quenching, whereas HBT derivatives with ortho or para methyl exhibited the least reactivity to hypochlorite. The LUMO and HOMO of 3-HBT were further verified to explain the fluorescence behavior by density functional theory (DFT) calculation. The excellent selectivity of 3-HBT toward hypochlorite against other reactive oxygen species (ROS) was also evaluated under the same conditions. The compounds emit bright green fluorescence in a solid-state, which is convenient for designing sensing devices for hypochlorite in water samples. Thus, the HBT derivatives with meta methyl (3-HBT) were successfully applied to fabricate paper sensors for the quantification of hypochlorite in tap water. Hence, the fluorescent 3-HBT exhibits great promise as a selective and sensitive hypochlorite probe in chemical and biological applications.

ДОСЛІДЖЕННЯ ПРОЦЕСІВ ОЧИЩЕННЯ ВОДИ ВІД ІОНІВ МАНГАНУ ПРИ ВИКОРИСТАННІ РОЗЧИНІВ НАТРІЙ ГІПОХЛОРИТУ

The creation of effective demanganization technologies by the development of new and intensification of known processes of manganese removal from natural waters are currently of increasing importance.The search for promising ways to demanganize water to regulatory values is a topical issue for the modern water treatment domain.Recent publications of methods for extraction of manganese ions from water by sorption, membrane, ion exchange methods were reviewed. The prospects of application of oxidative methods for water demanganation are shown.The purpose of the article is to investigate the manganese ions removal methods from water during their oxidation by sodium hypochlorite and to establish the dependence of the efficiency of demanganization on the consumption of oxidizing agent and the concentration of manganese ions in water.The study presents the application of sodium hypochlorite as an oxidant in the purification of artesian water from manganese ions. It was determined in static conditions that the degree of manganese removal is affected by both its initial concentration in water and the dose of sodium hypochlorite. Water purification process is more efficient with initial manganese concentrations above 5 mg/dm3. At a manganese ion concentration 30 mg/dm3, its complete removal was achieved in 4 hours of settling at a stoichiometric ratio of manganese and sodium hypochlorite in water and at any excess of oxidant. The process of manganese ions oxidation in artesian water by sodium hypochlorite depending on its dose and contact time was studied. The dose of oxidant for the removal of manganese ions from artesian water was also determined. Thus, the research allowed to improve the methods of water purification from manganese ions during their oxidation by sodium hypochlorite and found that the water purification efficiency increased both with increasing consumption of oxidizing agent and increasing the concentration of manganese ions in water.

An optical strategy for detecting hypochlorite in vitro and cells with high selectivity and stability based on a lanthanide-doped upconversion probe.

The excessive use of sodium hypochlorite disinfectant for preventing COVID-19 can be harmful to the water environment and humans. More importantly, owing to hypochlorite being a biomarker of immune responses in living organisms, its abnormal production can damage nucleic acids and protein molecules, eventually causing many diseases (even cancer). Exploring a reliable, rapid, and non-invasive method to monitor the hypochlorite level in vitro and in cells can be significant. Herein, we report a novel ratiometric fluorescence sensing strategy based on Astrazon Brilliant Red 4G dye-sensitized NaGdF4:Yb3+, Er3+@NaYF4 core-shell upconversion nanoparticles (UCNPs@ABR 4G). Based on the combination mechanism of the fluorescent resonant energy transfer effect (FRET) and redox, a linear model of fluorescence intensity ratio and hypochlorite concentration was constructed for a fast response and high selectivity monitoring of hypochlorite in vitro and in vivo. The detection limit was calculated to be 0.39 μM. In addition, this sensing strategy possessed good stability and circularity, making it valuable both for the quantitative detection of hypochlorite in water and for the visualization of intracellular hypochlorite. The proposed optical probe is promising for the efficient and stable non-invasive detection of hypochlorite.

Quantification of Hypochlorite in Water Using the Nutritional Food Additive Pyridoxamine

Chlorine is a widely used disinfectant and oxidant used for an array of municipal and industrial applications, including potable water, swimming pools, and cleaning of membranes. The most popular method to verify the concentration of free chlorine is the colorimetric method based on DPD (N, N-diethyl-p-phenylenediamine), which is fast and reasonably cheap, but DPD and its product are potentially toxic. Therefore, a novel, environmentally friendly colorimetric method for the quantification of residual chlorine based on the food additive pyridoxamine (4-(aminomethyl)-5-(hydroxymethyl)-2-methylpyridin-3-ol) was investigated. Pyridoxamine is a B6 vitamin with an absorption maximum at 324 nm and fluorescence emission at 396 nm. Pyridoxamine reacts rapidly and selectively with free chlorine, resulting in a linear decrease both in absorbance and in emission, giving therefore calibration curves with a negative slope. The pyridoxamine method was successfully applied for the quantification of free chlorine from 0.2 to 250 mg/L. Using 1 cm cuvettes, the limit of quantification was 0.12 mg Cl2/L. The pyridoxamine and the DPD methods were applied to actual environmental samples, and the deviation between results was between 4% and 9%. While pyridoxamine does not react with chloramine, quantification of monochloramine was possible when iodide was added, but the reaction is unfavourably slow.

An aggregation-induced emission (AIE)-active fluorescent chemodosimeter for selective sensing of hypochlorite in water and solid state: Endogenous detection of hypochlorite in live cells

Hypochlorite (ClO−) being an important reactive oxygen species plays a crucial role in the oxidative damage to tissue and other various diseases. Highly selective, sensitive, and quick detection of aberrant ClO− is vital for the protection of living organisms and the environment. Accordingly, fluorescent molecules are most effective sensor system for ClO−. Herein, we have synthesized and characterized a water soluble AIE-active tetraphenylethylene (TPE)-based fluorescent molecule TPE−Py+ (TPP) for rapid (10 s) and selective detection of ClO− based on ClO− induced oxidation of N-alkylpyridinium to N-methyl-2-pyridone. ClO− mediated aggregation-induced emission (AIE) enhancement corresponds to turn-on response. Scanning electron microscopic (SEM) study supports AIE behavior of the probe upon treatment with ClO−. The detection limit of TPP for ClO− was found to be 8.89 nM and exhibited high selectivity among other possibly interfering analytes (ROS, RNS, other ions). TPP-based handy test kits were developed for the solid-state detection of ClO− in environmental samples. Furthermore, our probe was effective in detecting ClO− in real water samples, fetal bovine serum and able to detect endogenous ClO− in live cell.

Chemosensor-Anchored Halloysite Nanotubes for Detection and Removal of Hypochlorite in Water

Preparation of a smart tool for simultaneous detection and removal of hypochlorite (ClO–) in water, a kind of serious persistent pollutant in industrial wastewater and even in tap water, is a puzzling issue in the chemosensing field. Here, halloysite nanotubes (HNTs), a natural product with excellent dispersibility in water, were employed as the scaffold to solve the urgent problem. The diaminomaleonitrile moiety, accompanying with the coumarin derivative as a chemosensor unit, was decorated on the surface of the HNTs. The diaminomaleonitrile group can be transferred into substituted imidazole formation and thereby triggers strong fluorescence emission upon ClO–, which triggers a dramatically “turn-on” fluorescence change and reduce ClO– into eco-friendly chloridion (Cl–). The detection and removal capacities show high selectivity over other commonly used ions. These results suggest that the smart nanocomposite can be used in the synchronous detection and removal of ClO– in water, which may pave a path in water quality monitoring and treatment.

A selective fluorescence sensor for hypochlorite used for the detection of hypochlorite in zebrafish

Hypochlorite is used as a water disinfectant and it is also produced by biological organisms. Its detection and quantification is important and could lead to its mechanism of reactivity in cells. We have synthesized a new fluorescence sensor for hypochlorite based on bithiophene and furan-carbohydrazide. The sensor shows increased fluorescence as a function of hypochlorite and is selective for hypochlorite. Fluorescence enhancement due to hypochlorite is observed when the sensor is used in aqueous solutions at neutral pH values. Using the sensor, the detection limit for hypochlorite is 4.2 µM, making the sensor practical to determine hypochlorite in water. Applying the sensor to aide in the detection of hypochlorite in zebrafish, showed localization of ClO−/HClO in the air bladders and eyes of zebrafish.

A 7-diethylaminocoumarin-based chemosensor with barbituric acid for hypochlorite and hydrazine

A chemosensor was synthesized conveniently by the condensation between 7-diethylaminocoumarin and barbituric acid, which was used successfully for the detection of hypochlorite and hydrazine with excellent performances. This chemosensor underwent remarkable color change and turn off fluorescence in solution, while revealed turn on fluorescence on the filter paper in the presence of hypochlorite. In addition, it exhibited obvious fluorescence enhancement in solution, while no fluorescence change on the test paper after addition of N2H4. As a result, this chemosensor could be a potential candidate for hypochlorite and hydrazine in different media through two distinct response modes. It could realize the detection of hypochlorite in water with a low detection concentration of 2 μM by test strip, and trace hydrazine in aqueous solution and living HepG2 cells by the mean of fluorescence signal. Moreover, the sensing mechanisms of this chemosensor towards hypochlorite and hydrazine were suggested by HRMS and 1H NMR spectra, in which the coumarin structure was destroyed by hypochlorite and the barbituric acid was removed by hydrazine, respectively.

Self-assembled nanofibers of perylene diimide for the detection of hypochlorite in water, bio-fluids and solid-state: exogenous and endogenous bioimaging of hypochlorite in cells.

A fluorescent probe PDI-DAMN based on perylenediimide containing diaminomaleonitrile at the bay-position was designed and synthesized for the detection of ClO-. PDI-DAMN self-assembled as nanofibers with diameters in the range of 100-200 nm in H2O : CH3CN (1 : 1). The addition of ClO- into PDI-DAMN resulted in the disintegration of nanofibers into flake-like aggregates of smaller size (50-80 nm) as supported by SEM and DLS data. The addition of ClO- to HEPES buffer-CH3CN solution (1 : 1, v/v, pH 7.4) of PDI-DAMN caused a hypochromic effect on the ICT band at 528 nm and 'turn-on' fluorescence enhancement at 508/554 nm due to the oxidative cleavage of -C[double bond, length as m-dash]N- bond. A linear correlation plot between the concentration of ClO-versus fluorescence intensity (R2 = 0.9968)/absorbance (R2 = 0.9988) in the concentration range 0-7 nM (fluorescence)/0-90 nM (absorbance) could determine ClO- with the detection limits of 1 and 10 nM, respectively. Optical studies performed on spiked urine and blood serum samples showed good estimation and recovery of ClO- (100 ± 5%). TLC-based test-strips coated with PDI-DAMN changed colour upon the addition of ClO- with detection as low as 7.44 ng cm-2. The application of PDI-DAMN for the bio-imaging of both exogenous and endogenous ClO- in MG-63 cells with good biocompatibility has also been demonstrated. The detailed mechanism of the interactions of ClO- with PDI-DAMN using 1H NMR titration, DFT studies and response mechanism of pH are also discussed.

A novel colorimetric and far-red emission ratiometric fluorescent probe for the highly selective and ultrafast detection of hypochlorite in water and its application in bioimaging.

Hypochlorous acid (HOCl)/hypochlorite (OCl-), an important reactive oxygen species, plays a number of important roles in various physiological processes. However, abnormal levels of OCl- can cause many serious diseases, such as atherosclerosis, rheumatoid arthritis, cardiovascular disease, and cancer. The development of efficient methods to monitor OCl- in biological systems is therefore of particular importance. Thus, we herein report a novel isophorone-based fluorescent probe, i.e., DCOH-FR-OCl, for OCl- detection. This probe was found to exhibit colorimetric and far-red ratiometric fluorescence response signals, excellent selectivity and sensitivity for OCl- (detection limit, 88.06 nM), a remarkably large Stokes shift (158 nm), an ultrafast response (completed within 3 s), perfect photostability, and good water solubility (100% in aqueous media). DCOH-FR-OCl, as we know, is the first probe that can detect OCl- by using two different response signals at an ultrafast speed with a large Stokes shift in fully aqueous media. Furthermore, DCOH-FR-OCl can be successfully employed in the real-time imaging of endogenous and exogenous OCl- in living cells.

Cleaning accident kills Buffalo Wild Wings employee

You should never mix bleach with anything, but that’s what happened during an accident at a Buffalo Wild Wings in Burlington, Massachusetts, on the evening of Nov. 7. According to Burlington Fire Department assistant chief Michael Patterson, an employee spilled the cleaner Scale Kleen on the floor. Later, a different employee started to clean the floor with another cleaner, called Super 8. The mixture turned green and started bubbling. The bubbling puddle emitted fumes, driving employees and customers to evacuate the restaurant. The manager, 32-year-old Ryan Baldera, attempted to clean up the liquid and was overcome by the fumes. He died later at the hospital, a Burlington Fire Department press release says. According to safety data sheets, Super 8 is a mixture of 8–10% sodium hypochlorite in water, stronger than household bleach. Scale Kleen contains 22–28% phosphoric acid, 18–23% nitric acid, and less than 1% urea. Generally, strong cleaners like

Functionalized silicon nanoparticles as fluorescent probe for detection of hypochlorite in water

In this work amine functionalized silicon nanoparticles colloid is utilized to prepare a fluorescent probe for detecting low concentration levels of hypochlorite in water. The sensor is prepared by adding organosilane in silicon nanoparticles colloidal solution which freshly synthesized by laser ablation of silicon target in distilled water. The amine-terminated surface of silicon nanoparticles is confirmed using Fourier transform infrared, UV–vis absorption spectroscopy and transmission electron microscopy methods. The photoluminescence measurements of the functionalized silicon nanoparticles colloid exhibit high photostability and good reproducibility making them ideal fluorescent probes for sensing applications. It shows high sensitivity, excellent selectivity and rapid response (˜6 min) toward hypochlorite. The room temperature fluorescent sensor detects hypochlorite of water in the linear concentration range from 1 to 5 μM with a 0.2 μM detection limit. The sensor properties including high sensitivity, fast response and facile synthesis of the amine-functionalized silicon nanoparticles are compared with other reports in literature for fluorescent detection of hypochlorite in water.

Nanomolar colorimetric hypochlorite sensor in water.

Hypochlorous acid is present in several biological systems and plays a pivotal role in bioprocesses. The acid also finds application in industrial and synthetic spheres. The ecological toxicity of elevated hypochlorite concentrations in aqueous media has been thoroughly documented. As a consequence, there is a pressing need to develop quantitative and qualitative methods for the detection of hypochlorite in water. In this regard, nanomolar detectable, non-toxic and intensely coloured probes based on commercially available dyes such as Fuchsin basic, Methyl violet, Acid red-1, and Trypan blue have been successfully applied for hypochlorite detection in fully aqueous media. In all of these cases, specific and selective naked eye sensing of hypochlorite was achieved. As a rule of thumb, the addition of hypochlorite to a dye solution results in discoloration. The sensing mechanism follows an oxidative chemodosimetric approach and UV-Vis, as well as NMR titration experiments, support the oxidative cleaving of the molecular framework even in the presence of hypochlorite in trace amount (>1 nM). Furthermore, probes are subjected towards real-sample analysis of daily use water which contains bleaching agent and found to be promising in strip test too. Limits of detection of the dyes Fuchsin basic, Methyl violet, Acid red-1 and Trypan blue are 0.86 nM, 2.97 nM, 2.31 nM and 30 μM respectively. These dyes are promising analytical tools for the detection of hypochlorite.

Contamination of drinking water soon after cement mortar lining renovation depending on the disinfectant doses

The quality of water transported through freshly cemented water pipes depends not only on the type of cement used. The other factor affecting the degree of leaching pollutants from cement coatings is the chemical parameters of the water. A disinfection process is necessary for maintaining water which is safe for human health and high quality. However, simultaneously, the presence of disinfectant in water may cause some problems. The results of the experiments performed showed that independently of the concentration of sodium hypochlorite in water, rapid changes of water pH soon after cement mortar lining renovation may always be expected. The addition of disinfectant to water causes an increase in pollutants leaching from cement coatings, even in the case of a low disinfectant dose. Although the concentration of disinfectant in water has a differential impact on the degree of pollutants leaching from cement coatings, the increase in the leaching of the pollutants is not proportional to the disinfectant concentration.

A water-soluble fluorescent probe for monitoring hypochlorite in water and in living cells

A novel water-soluble fluorescent probe based on the removal of HON moiety was presented, which could monitor ClO− with rapid response and excellent selectivity. In physiological pH condition, a good linear balance between the fluorescence intensity and the ClO− concentration was found with high sensitivity (8.3 nM). Additionally, this probe could be immobilized on test strips, which exhibited visible changes under UV light illumination. Its outstanding performance made the successful application in water samples and RAW264.7 cells.

Reaction mechanisms of 3-amino-4-nitro-furoxan formation by 3-amide-4-nitro-furoxan and sodium hypochlorite in water and benzene solvents

Synthesis of new furoxan-based compounds has been a hot research topic in order to explore the energetic materials with good application prospect. 3-amino-4-nitro-furoxan is a precursor for synthesis of furoxan derivatives because that the amino groups are prone to be substituted by nucleophiles. A theoretical research is conducted for the formation reaction of 3-amino-4-nitro-furoxan by 3-amide-4-nitro-furoxan and sodium hypochlorite in water and benzene solvents using the density functional theory (DFT) and CCSD coupled cluster method to reveal the formation mechanism and explore new synthesis routes. The structures and energies of intermediates and transition states in the possible reaction pathways are given, and the potential energy surfaces of the every reaction channels are mapped. The results indicate that the formation mechanism is mainly through two stages: generation and hydrolysis of isocyanate. Hydrogen bond plays an important role for the hydrolysis process. The formation mechanism is shown to be dependent on the polarity of solvent. The hydroxyl ion (OH−), originated from the basic properties of sodium hypochlorite solution, is shown to be more likely first attacker than the hypochlorite ion (OCl−) for the reactant 3-amide-4-nitro-furoxan due to the low active barrier in the polar water solvent. But the OCl− dominates the reaction in benzene solvent where the isocyanate is formed via the dehydration chlorination by OCl− and Hofmann rearrangement with the elimination of chloride ion. The isocyanate is then hydrolyzed through addition of a H2O molecule to the NC double bonds, rotation of the hydroxyl hydrogen, transfer of hydrogen to the N atom in the amide group and the removal of a CO2 molecule to form the final product. The benzene solvent is more suitable than water solvent for the formation reaction due to the lower active barrier of 46.4 kcal/mol. The reaction is not feasible at room temperature and raising properly temperature of system would be requisite to realize the synthesis reaction.

Variability of physical and chemical parameters of water from fountains in health resorts

The aim of the study is to assess the quality of water from selected recreational fountains in Ciechocinek and Inowrocław health resorts. All analyzed water fountains are characterized by seasonal changes in their discharge. The exceedance of biochemical oxygen demand and chemical oxygen demand values found in the water samples may indicate water contamination with compounds of organic origin getting from the external environment to the basin of the fountain or too little recirculation of water. A significant improvement in water quality was noted in fountains in which water exchange occurred due to, for example, its failure. In addition, the water was characterized by a relatively high content of general hardness and conductivity. Reported exceedances of water quality parameters disqualify it for direct human consumption. It does not meet the requirements for drinking water. It is recommended to introduce supervision over the quality of water from fountains by the bodies of the State Sanitary Inspection in the form of water monitoring in order to eliminate from the water compounds that may have a negative impact on human health. It is recommended to regularly use pre-filtration, chlorination and sodium hypochlorite in water in fountains to eliminate physical impurities.