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An efficient chlorination reaction of in situ generated (β-diazo-α,α-difluoroethyl)phosphonates has been achieved with hydrochloric acid as a chlorine source under mild and operationally convenient conditions. The reaction does not need any catalyst and tolerates a wide scope of substrates, which affords the (β-chlorodifluoroethyl)phosphonate products in good to excellent yields. This reaction represents the first example of the halogenation of difluoroalkyl diazo compounds, and also provides an easy way for the synthesis of difluoromethylenephosphonate-containing compounds.

Chlorine is a harmful trace element in coal. During coal combustion, the chlorine undergoes complex changes and transfers to the gas, and forms chlorine-containing substances. This paper summarizes the field test data of chlorine emission from domestic coal-fired units, and analyzes the chlorine emission and control characteristics. The results show that during the combustion process, the chlorine in coal is released into flue gas, mainly HCl, and a small amount of Cl2 and particulate Cl. Conventional pollutant control facilities affect the form and concentration of Cl. The impact of dust removal facilities on Cl is mainly reflected in the coordinated removal of particulate Cl. The impact of wet desulfurization facilities on Cl is mainly reflected in the coordinated removal of HCl. The Cl emission concentration in flue gas of coal-fired units is 0.85 mg/m3, which meets the emission requirements. Chlorine is transferred from coal to fly ash, desulfurization wastewater and desulfurization gypsum, so the secondary pollution of chlorine should be paid much attention. HCl in coal-fired flue gas has an adverse effect on wet desulfurization facilities. Based on the material balance of chloride ions in absorption tower slurry, this paper proposes a technical idea for removing HCl from flue gas with alkaline absorbents.

In this study, chlorine bypass system (CBS) dust is proposed as a new alkali activator and the feasibility of applying CBS dust for high-volume blast-furnace slag (HVBFS) mortar is confirmed. CBS is a dust-collecting system for the cement-manufacturing process that collects dust with chloride and alkali. In general, most of the collected CBS dust in South Korea is wasted. As an effort to reduce waste and incidental costs during the cement-manufacturing process, in this study, cement powder was replaced by CBS dust as an alkali activator for blast-furnace slag. From the experiment of HVBFS mortar activated with various CBS dust proportions, favourable results were observed in terms of fluidity and air content when the CBS dust replacement exceeded 5%. Additionally, regarding strength development, CBS dust was successful as an alkali activator for the latent hydraulic reaction of blast-furnace slag. Therefore, when CBS dust was used as a 5% replacement, its efficiency as an alkali activator in which a large amount of blast-furnace (HVBFS) slag was substituted under the research conditions in this study was confirmed in terms of fluidity and strength development performance.

This study examines the influence of chlorine disinfectant type, water use frequency (stagnation time), and water heater temperature on the growth and persistence of microbes, including nontubercul...

Aims This study aimed to investigate the physiological responses of two gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two gram-positive bacteria (Enterococcus faecalis and Bacillus sphaericus) to ultraviolet (UV) and chlorine disinfection. Methods and Results Bacterial inactivation by UV and chlorine disinfection were evaluated with a plate count method for culturability, FCM and PMA-qPCR for membrane integrity and DyeTox13-qPCR for enzymatic activity, respectively. Both UV and chorine disinfection caused complete loss of culturability while membrane integrity remained intact after UV disinfection. Both DyeTox13-qPCR and PMA-qPCR showed high ΔCt values up to 8.9 after chlorine disinfection, indicating that both methods were able to distinguish non-treated from chlorine-treated cells. Although PMA-qPCR could not differentiate membrane integrity of cells on UV exposure, DyeTox13-qPCR showed significant differences in ΔCt values of 5.05 and 10.4 for gram-negative (E. coli) and gram-positive (Enterococcus) bacteria, respectively. However, DyeTox13-qPCR for gram-negative bacteria displayed relatively small differences in ΔCt values compared with gram-positive bacteria. Conclusion UV and chlorine disinfection led to changes in physiological state of gram-negative and gram-positive bacteria. Particularly, UV disinfection could induce active but non-culturable (ABNC) for gram-negative bacteria and dormant cell for gram-positive bacteria where intact cells no longer showed the enzymatic activity. Significance and Impact of the Study UV and chlorine are commonly used to disinfect water, food and fomites to inactivate pathogenic bacteria. However, a viable but non-culturable (VBNC) state of bacteria induced by disinfection may underestimate the health risks because of the potential resuscitation of VBNC cells. This study highlighted that bacteria could undergo different physiological (ABNC or dormant) states during UV and chlorine disinfection. In addition, viability PCR techniques could provide insight into the changes in physiological states during disinfection processes.

It is highly important to design and develop appropriate insoluble anodes for industrial Cu electroplating to lower the amount of organic additives that this process consumes. Conventionally, this rapid consumption of additives (e.g., brighteners, suppressors, or levelers) is known to be due to the active radical species (e.g., OH) formed during oxygen evolution. In this study, we found that trace amounts of chloride ions present in the electroplating bath are the source of the active chlorine species that accelerate the breakdown at the insoluble anode. A sacrificial, perfluorinated polymer coating effectively decreased the emission of active chlorine species from the electrode, thereby lowering the consumption of the brightener. This study reveals that the suppression of chlorine evolution at the anode can be an effective approach for decreasing brightener consumption during Cu electrodeposition.

Monoethylene glycol (MEG) aqueous solution was regenerated in the forward osmosis (FO) process for further use. For this purpose, a novel thin-film composite (TFC) membrane was prepared and applied. To mitigate the internal concentration polarization (ICP), a proper support with a low structural parameter and high hydrophilicity was utilized. In addition, a chlorine-tolerant polyamide layer was synthesized using trimesic acid trichloride (TMC) and 4-methyl-m-phenylenediamine (MMPD) monomers. The latter aimed to improve the chlorine resistance of the polyamide layer and increase the membrane lifespan in practical applications where oxidants are utilized for membrane cleaning. The effect of MMPD concentration and interfacial polymerization (IP) reaction time on the characteristics of the top layer was studied thoroughly. During the FO test, the TFC membrane whose polyamide layer was prepared with 2 wt. % MMPD concentration and 1.4 min reaction time exhibited the highest reverse flux selectivity at 5.71 L/g, while its water flux and MEG rejection during the regeneration of a MEG aqueous solution sampled from a gas processing plant were 35.40 LMH and 93.85%, respectively. The chlorine exposure test confirmed a significantly higher chlorine resistance for the MMPD/TMC polyamide layer compared to the conventional MPD/TMC one.

We explored a unique concept in this study to develop a membrane containing a hierarchical porous architecture derived by etching a specific component from a demixed UCST blend as the support layer and a free-standing GO and a polyamide (PA) layer as functional surfaces. To selectively sieve ions and improve chlorine tolerance performance, three different strategies were proposed here. In the first case, the free-standing GO membrane was used as the active layer. In the second case, the free-standing GO was positioned in tandem with the PA layer formed

A significant amount of chlorine, and alkali and alkaline earth metal (AAEM) in food waste has been a major limitation to the utilization of food waste as fuel. The present study aims to investigate the behavior of chlorine and AAEM in food waste biochar during pyrolysis, demineralization, and combustion. Food waste compost (FWC) and food waste feedstock (FWF) were selected as raw materials. Three different pyrolysis temperatures from 300 to 500 °C and two demineralization processes, water and CO2–saturated water, were employed. As the pyrolysis temperature increased, crystallized salt was removed through demineralization, which further increased the heating value. Effective removal of chlorine was demonstrated in both demineralization methods. During demineralization, re-adsorption of Ca on food waste biochar occurred, which was alleviated by CO2-water demineralization. The total amounts of volatilized Cl and AAEM after CO2–water demineralization were reduced by 74.79–99.38% for FWF and 98.34–99.9% for FWC compared to raw biochar. Furthermore, slagging and fouling potentials for all food waste biochar samples were estimated using various indices. The proposed behavior of Cl and AAEM in food waste biochar during various fabrication conditions provides insight into how food waste biochar can be applied in thermos-electric power plant for co-firing with coal.

Introduction Human norovirus (HuNoV) is a leading cause of infectious gastroenteritis. Since HuNoV shows resistance to alcohol, chlorine-based sanitizers are applied to decontaminate the virus on environmental surfaces. Chlorous acid water (CA) has been recently approved as a novel chlorine-based disinfectant categorized as a Type 2 OTC medicine in Japan. In this study, we aimed to evaluate the capability of CA to inactivate HuNoV. Methods HuNoV (genogroups GII.2 and GII.4) was exposed to the test disinfectants including CA and sodium hypochlorite (NaClO), and the residual RNA copy was measured by reverse transcription quantitative PCR (RT-qPCR) after pretreatment with RNase. In addition, the log10 reduction of HuNoV RNA copy number by CA and NaClO was compared in the presence of bovine serum albumin (BSA), sheep red blood cells (SRBC), polypeptone, meat extract or amino acids to evaluate the stability of these disinfectants under organic-matter-rich conditions. Results In the absence of organic substances, CA with 200 ppm free available chlorine provided >3.0 log10 reduction in the HuNoV RNA copy number within 5 min. Even under high organic matter load (0.3% each of BSA and SRBC or 0.5% polypeptone), 200 ppm CA achieved >3.0 log10 reduction in HuNoV RNA copy number while less than 1.0 log10 reduction was observed with 1,000 ppm sodium hypochlorite (NaClO) in the presence of 0.5% polypeptone. CA reacted with only cysteine, histidine and glutathione while NaClO reacted with all of the amino acids tested. Conclusions CA is an effective disinfectant to inactivate HuNoV under organic-matter-rich conditions.

A UV-LED at a fixed wavelength is increasingly employed in the UV/chlorine process to degrade contaminants of emerging concern. However, degradation of contaminants and formation of disinfection by-products (DBPs) in post-chlorination would be significantly altered in the presence of nitrite because of the generation of reactive nitrogen species (RNS). As nitrite has a maximum absorption at ∼350 nm, its impact on the performance of the UV-LED365/chlorine process and subsequent formation of DBPs was investigated. The presence of nitrite in the UV365 irradiation process accelerated the degradation of bisphenol A (BPA), while slightly inhibiting the degradation of BPA in the UV365/chlorine process; nitrite in UV365 and UV365/chlorine processes resulted in the non-negligible formation of trichloronitromethane (TCNM). The concentration of generated DBPs and the corresponding cytotoxicity and genotoxicity all changed because of the presence of nitrite; the concentrations of nitrite, pH, and UV fluence were important factors for the formation of TCNM during the UV365/chlorine/nitrite process. Therefore, the impact of nitrite on the TCNM formation in the UV-LED365/chlorine process is worth noting.

Role of chemical elements (ChE) in etiology and pathogenesis of Riedel’s disease (RD) is unclear. The aim of this exploratory study was to assess whether there were significant changes in thyroid tissue levels of eight ChE (Br, Ca Cl, I, K, Mg, Mn, and Na) are present in the fibrotic transformed thyroid. Eight ChE of thyroid tissue were determined in 6 patients with RD. The control group included thyroid tissue samples from 105 healthy individuals. Measurements were conducted using non-destructive instrumental neutron activation analysis with high-resolution spectrometry of short-lived radionuclides. Reduced mean values of Ca and I content in 6.3 and 6.7 times, respectively, while elevated level of Br in 5.1 times were found in thyroid with RD in comparison with normal level. Because considerable changes in some ChE contents in tissue of thyroid with RD were found, it is reasonable to assume that the levels of these ChE in affected thyroid tissue can be used as RD markers. However, this topic needs additional studies.

The development of laser spectroscopy has made it possible to measure minute changes in the concentrations of trace gases and their isotopic analogs. These single or even multiply substituted species occur at ratios from percent to below parts per million and contain important information concerning trace gas sources and transformations. Due to their low abundance, minimizing spectral interference from other gases in a mixture is essential. Options including traps and membranes are available to remove many specific impurities. Methods for removing CH4, however, are extremely limited as methane has low reactivity and adsorbs poorly to most materials. Here we demonstrate a novel method for CH4 removal via chlorine-initiated oxidation. Our motivation in developing the technique was to overcome methane interference in measurements of N2O isotopic analogs when using a cavity ring-down spectrometer. We describe the design and validation of a proof-of-concept device and a kinetic model to predict the dependence of the methane removal efficiency on the methane concentration [CH4], chlorine photolysis rate JCl2, chlorine concentration [Cl2] and residence time tR. The model was validated by comparison to experimental data and then used to predict the possible formation of troublesome side products and by-products including CCl4 and HCl. The removal of methane could be maintained with a peak removal efficiency >98 % for ambient levels of methane at a flow rate of 7.5 mL min−1 with [Cl2] at 50 ppm. These tests show that our method is a viable option for continuous methane scrubbing. Additional measures may be needed to avoid complications due to the introduction of Cl2 and formation of HCl. Note that the method will also oxidize most other common volatile organic compounds. The system was tested in combination with a cavity ring-down methane spectrometer, and the developed method was shown to be successful at removing methane interference.

Maintaining a residual disinfectant/oxidant (e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid (HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts (DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogen-containing oxidants via three pathways: (1) catalytic disproportionation to yield an oxidized form of halogen (i.e., halate) and reduced form (halide for chlorine and bromine or chlorite for chlorine dioxide), (2) oxygen formation, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of CuO on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important (exceeding 10 µg/L) when initial bromide concentration is above 400 µg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at pH 8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.

In CO oxidation, Cu/CuOx species are known to increase the catalytic activity and improve the sintering-resistance of Au supported catalysts, particularly in the case of non-reducible oxide supports such as SiO2. Nonetheless, there is a lack of detailed information about the impact of Cu species on the stability of Au nanoparticles (NPs) supported on CeO2, one of the most important reducible oxide supports used in catalysis. Due to the reducibility of this oxide, the stability of the metallic phase and the metal-support interaction are strongly dependent on the atmosphere, i.e., oxidizing or reducing conditions. Besides, how residual contaminants from the preparation of the catalysts, such as chlorine, may affect the catalytic activity is not clear for the AuCu/CeO2 system. In this work, we used Au and AuCu colloidal NPs with initially well-defined size and shape to produce model CeO2 supported catalysts to better comprehend the role of the Cu and chlorine on the sintering-resistance of Au NPs and its impact in the catalytic performance of CO oxidation (CO-OX). We show that while the activation of the catalysts by hydrogen enhanced the sintering-resistance of the metallic phase in AuCu/CeO2, activation by oxygen was more effective to generate the most active sites. The presence of chlorine induced the sintering of the metallic phase, particularly after the activation by hydrogen. Besides, the results suggest that the chlorine partially poisoned the Au-CuOx-CeO2 interfacial species, decreasing the catalytic performance.

Ethylene epoxidation transpires with high ethylene oxide (EO) selectivity (∼90%) over promoted Ag/α-Al2O3 catalysts via the concurrent propagation of ethylene oxidation, chlorine deposition and rem...

Headspace-gas-chromatography ion-mobility spectrometry (HS-GC-IMS) proved the diversity of volatile chlorinated compounds (VCCs) in frying oil in this work. First, the VCCs were obtained by headspace by heating the frying oil at 80 °C for 30 min. Then, those compounds were separated by GC capillary column in the first dimension and by IMS in the second dimension, respectively. And at last, those compounds were detected in negative ion mode for non-targeting. The study results indicated that VCCs' formation depends on the contents of NaCl and water, heating temperature and time, and the types of oil. The refining process does not affect the detection of VCCs, indicating the durability of such targets as indicators for assessing deep-frying oil. Using HS-GC-IMS, the VCCs were detected to evaluate 16 authentic refined deep-frying oils from the market with an accuracy of 100%.

Electrolyzed waters, containing mainly hypochlorous acid, are used in dental practice because of their high microbicidal effect. For wider use, three neutral electrolyzed water-based gels, namely, HOCl-containing aqueous gels were prepared with a thickening/gelling agent in this study. We evaluated their microbicidal effects against four strains and storage stabilities indicated by available chlorine concentration. Immediately after preparation, all gels (70 ppm) could completely remove microbes by a 3-min treatment. The gel prepared with xanthan gum remarkably reduced its available chlorine concentration even under shaded and refrigerated storage conditions, failing to maintain its microbicidal effect following 1-day storage, whereas other gels, prepared with carboxyvinyl polymer or agar, maintained effective concentration (>20 ppm), with high microbicidal effects following 9-day and 21-day storage, respectively. Neutral electrolyzed water-based gels might be useful to remove oral microbes. Based on our results, agar is the most suitable thickening/gelling agent from the viewpoint of storage stability.

Carcinogenic disinfection by-products (DBPs) are formed as the result of the chlorination of power plant water cooling systems for biofouling purposes. Effects of cooling water chlorination are noteworthy topics of discussion as they greatly affect aquatic life and; thus, raise environmental concerns. This study aims to examine the chlorine effect on varying sizes of surf clams (Mactra quadrangularis) by evaluating the lethal response (time to 100% mortality) and sublethal physiological responses (filtration rate and oxygen consumption rate) in different chlorine concentrations. The present study will provide a proper guideline to determine chlorine injection concentration that serves as an antifouling compound. The maximum time to reach 100% mortality at the chlorine concentration of 0.5 mg L−1 in Group I (small) and II (large) was 568.0 ± 42.1 and 824.0 ± 25.0 h, respectively. Although the time to 100% mortality decreased sharply at 1.0 mg L−1, no noticeable condition appeared above 1.0 mg L−1. Physiological responses, such as filtration rate and oxygen consumption rate, at a sublethal concentration decreased significantly along with the residual chlorine concentrations. At below TRC 0.5 mg L−1, M. quadrangularis showed weakened physiological responses, for instance declined feeding regimens, due to stress caused by chlorine. Longer exposure to chlorine at TRC lower than 0.5 mg L−1 can cause lack of growth, poor reproductive function, disease infection and even death in the M. quadrangularis population.

Simultaneous pollution degradation and disinfection were seldom discussed in the field of electrocatalytic oxidation. In this work, N-doped graphene (N-GN) was selected as anode to ensure the high performance of paracetamol (APAP) degradation. With N doping, the activity of N-GN is evidently improved because of the better surface area, active defects, and conductivity compared with graphene. The generation of active chlorine and O2.− on the N-GN surface played an important role in APAP degradation. Compared with other operation parameters (such as pH and current density), environmental microorganisms exhibited more negative interference for APAP degradation. However, evident disinfection effects can be observed because of the release of fulvic and humic acids from microorganisms. In particular, active chlorine is evidently more effective than O2.− for disinfection. The simultaneous APAP degradation and disinfection observed in this research provided the possible technology of electrocatalytic oxidation via N-GN for practical application.

A series of four different biomass feedstock was washed and hydrothermally carbonized at temperatures of 50 °C and 150–270 °C for four hours, respectively. For the first time both the resulting solid and liquid products were characterised and evaluated in a comprehensive study. Concerning fuel properties, HTC had a higher impact on the fuel quality than washing. HTC yielded hydrochar with higher carbon content than the starting material leading to a significant increase in heating value, while washing only had a minor effect on elemental composition and heating value. Treatment temperature was found to have the highest impact on LHV and elemental composition. Both washing and HTC proved effective in reducing potassium and chlorine content, while earth alkaline, phosphorous and silicon removal was limited. Process water characterisation revealed that filtrates from washing and HTC are acidic, with acidity being increased by HTC. Electrical conductivity of the effluent was found to correlate with the amount of electrolytes Na, K, Mg and Ca in the feedstock, thereby being feedstock dependent. COD, BOD5 and TOC values determined revealed that effluent from both washing and HTC is strongly contaminated by organic matter. The organic load was significantly higher in HTC effluents. Feedstock type was found to be the main influencing factor on effluent characteristics rather than HTC temperature. Nutrients were found in low concentrations. Graphic Abstract

Black aluminum dross (BAD) is a hazardous solid waste generated during the recycling process of aluminum scrap. The mixture of phases in BAD is complex, and the effective removal of harmful elements such as nitrogen and chlorine is the critical factor for enabling its utilization. In this paper, two processes for removing nitrogen and chlorine from BAD are proposed: 'washing dechlorination–roasting denitrification' and 'alkali-catalyzed denitrification and dechlorination.' A single-factor experimental method was used to optimize the influencing factors of the two processes, and the methods were compared to obtain the best denitrification and dechlorination process conditions. The results show that the alkali-catalyzed denitrification and dechlorination method for treating BAD has a higher nitrogen and chlorine removal rate and a lower cost. The optimal denitrification and dechlorination conditions are a temperature of 90 °C, a reaction time of 300 min, a 6:1 liquid–solid ratio (mL:g), a stirring speed of 300 r/min, and a particle size smaller than 150 mesh. Under optimal leaching conditions, the nitrogen and chlorine removal rates are 93.48% and 99.84%, respectively. In addition, the kinetic behavior of aluminum nitride in BAD under uncatalyzed and catalyzed conditions was studied. Under uncatalyzed conditions, the leaching process of aluminum nitride conforms to the unreacted nucleus model of mixed control of the chemical reaction and diffusion, with an apparent activation energy of Ea = 40.51 kJ/mol. Under alkali-catalyzed conditions, the leaching process of aluminum nitride is diffusion-controlled, and its apparent activation energy is Ea = 27.66 kJ/mol.

One of highest populated country is China where population of rural is 67% of the total population. The main issue that causing the rural environment of China-Jiangsu is treatment of domestic sewage waste-water. Basically, these arrives due to the untreated waste water from households and are directly flowing to water bodies that are nearby to their respective areas. More than 60% of people in China are affected by this physically causing huge health problems and spread of disease and also directly affecting living beings under water bodies. By this, sewage treatment plants were built by China 5-6 years ago but still the problem exists as the treatment wastewater hasn’t improved. So, in this paper we give a research area of how to improve household sewage wastewater treatment in better way and also give a futuristic way of the latest technologies in changing the wastewater treatment into an improved level. This study shows that we described the basic research framework for sewage wastewater treatment by improving with latest technologies.

Most published data on chlorine disinfection of bacteria are from experiments conducted using reference-strain bacteria cultured in a laboratory. However, indigenous environmental bacteria, such as...

Purpose In this study, new hybrid polymers composed of Zinc chloride (ZnCl2), acrylamide and chitosan were prepared at different ratios and temperatures. The effects of pH and polymer dosage were examined for different polymers to observe their efficiency in the removal of turbid water. The polymers’ zeta potential, morphology, elemental composition and functional groups were also identified and studied. Design/methodology/approach The free-radical polymerisation process was executed in the presence of N, N’-Methylene bis-acrylamide and potassium persulphate in one molar acrylamide solution. ZnCl2 and chitosan (CO) were later introduced into the suspension under nitrogen gas flow. Ratio and temperature were varied during polymerisation. The hybrid polymer produced, termed Polyacrylamide + chitosan oligosaccharide + zinc chloride (PAMCOZ), was analysed using Fourier transform infra-red spectroscopy attenuated total reflectance and scanning electron microscope with energy dispersive X-ray. The hybrid PAMCOZ was experimented with in high turbid kaolin suspension using jar testing analysis to see its ability as a coagulant. Findings The coagulation process using PAMCOZ with a ratio of 11 (3:2) at 70°C surrounding temperature showed a 100% reduction at pH 4 with 50 mg/L of the polymer. The functional groups present in ratio 11 polymer were hydroxyl, carbonyl, amide and methyl groups. In addition, several elements were spotted on the surface of PAMCOZ, such as zinc (Zn), carbon (C), chlorine (Cl), nitrogen (N) and oxygen (O). The effect of pH also demonstrated that PAMCOZ was unfavourable in an alkaline turbid water environment. Research limitations/implications Due to the research methodology approach, the research results may lack actual wastewater application. Therefore, researchers are encouraged to test the hybrid coagulant on raw wastewater, such as pulp and paper mill effluent with a high turbidity value similar to this study. Originality/value The polymerisation between zinc chloride, acrylamide and chitosan has not yet been applied. The different ratios and effects of temperature were analysed on PAMCOZ to see the turbidity removal. PAMCOZ showed better turbidity removal in acidic conditions.

A systematic study of halogenate(I/III) anions with polyatomic ligands is presented. The bis(perfluoro-tert-butoxy) halogenates(I) [X(OC4 F9 )2 ]- , X=Cl, Br, I, of chlorine, bromine, and iodine are prepared as their tetraethylammonium salts and characterized with IR, Raman, and NMR spectroscopic methods, as well as single-crystal X-ray diffraction analyses. Spectroscopical data are supported by quantum-chemical calculations. Additionally, the bonding situation of the species in question are analyzed and discussed. Furthermore, the oxidation to the corresponding halogenate(III) derivatives was studied. For [Br(OC4 F9 )2 ]- , oxidation with elemental fluorine gave [BrF2 (OC4 F9 )2 ]- . Iodide was directly oxidized by ClOC4 F9 to the IIII species [I(OC4 F9 )4 ]- , which is a surprisingly inert anion that might be used as a weakly coordinating anion (WCA) in the future. For [Cl(OC4 F9 )2 ]- , the decomposition products of the synthetic approaches towards a chlorine(III) system were analyzed.

The possibility of analyzing the amount of chlorine on the surface of stainless steel is investigated and a method for obtaining reproducible results by evening or eliminating the physicochemical features of surface ionization of a calibrant crystallized from a solution is described. It is shown that the main factor influencing the quality of calibration and analysis is the shape of the resulting drop and its size. It was also found that integrating the analytical signal over the entire drop is the most appropriate method for calibration and obtaining the most reproducible results. The main factors influencing the physicochemical characteristics of ionization and, as a consequence, the reproducibility of the calibration data are presented. It has been established that the method of calibration with the integration of a signal by a drop can be effectively used in the analysis of ultra-small amounts of chlorine on the surface of stainless steel in the range from 0.12 to 120 pmol/mm2. In this case, the proposed approach eliminates the physicochemical factors affecting the ionization efficiency, which limit the use of surface laser desorption/ionization for quantitative analysis.

The forward osmosis (FO) membrane exhibits great performance degradation when contacting with chlorine solutions. The damage of chlorine to membrane material will seriously reduce the lifetime of the membrane and increase the cost of membrane treatment technology. Here, we prepared chlorine-stable membranes by a covalent modification method with cyclohexylamine. The cyclohexylamine observably changed the surface morphology, the roughness (arithmetic average) of the membrane decreased from 22 to 17.2 nm. The addition of cyclohexylamine produced a denser sacrificial layer of short chain polyamide, which made modified membranes possess significantly better chlorine resistance with slightly declined water flux. The water flux of the optimal modified membrane was 10.78 Lm−2 h−1, only 13% less than that of the pristine membrane. Importantly, after 20,000 ppm·h chlorine exposure, the membrane with 1.5 wt% cyclohexylamine had a salt rejection of 77.2% and showed 26.0% lower water flux than pristine TFC (thin film composite) membrane in FO mode. Notably, the grafting membranes could maintain a high performance under acidic chlorination conditions. The membrane with best performance had a salt rejection of 81.6%, exhibiting 24.4% higher salt rejection than pristine membrane with 20,000 ppm·h chlorine exposure at a pH of 4. The cyclohexylamine endowed the FO membrane with better chlorine resistance, making it attractive for the development of chlorine-resistant membrane for environmental and desalination processes. HIGHLIGHTS The addition of cyclohexylamine produced a chlorine-resistant sacrificial layer.; The 1.0 wt% addition of cyclohexylamine did not significantly decrease the water flux of the forward osmosis membrane.; Under acidic conditions, cyclohexylamine could still significantly improve the chlorine resistance of forward osmosis membranes.

The demand for sustainable energy sources urges the development of efficient and earth-abundant electrocatalysts. Herein, chlorine assisted ion-exchange and in-situ sulfurization processes were combined to construct CuCo2S4@(Cu,Co)2Cl(OH)3 heterostructures from Cu(OH)2 nanoarrays. Chlorine element in the cobalt source stimulated the formation of (Cu,Co)2Cl(OH)3 precursor, and further facilitated partial transformation of the precursor to CuCo2S4 on the surface to achieve composite structure. The mixed valences of Co element (Co3+ in CuCo2S4 and Co2+ in (Cu,Co)2Cl(OH)3) and O S interpenetrated nanointerface in the composite catalysts provided low electron transfer resistance for good alkaline oxygen evolution reaction (OER) activities. In 1 mol L−1 KOH electrolyte, the overpotentials of the optimal composite catalyst reached 253 and 290 mV respectively at the current density of 20 and 50 mA cm−2, which is comparable to the activity of commercial Ir/C (281 mV@20 mA cm−2). These findings could provide opportunities for designing effective and inexpensive composite electrocatalysts through nanointerface engineering strategy.

Presented paper identifies the possible corrosion problems related to animal waste incineration since it is a key issue for their use in the power sector. Cow dung as an example of animal-origin biomass is examined in terms of high-temperature corrosion and slagging hazards in comparison with commonly used mixed straw. Results of the laboratory-scale corrosion studies of pure ash deposits on two steel alloys: 16Mo3 and 10CrMo9–10 are reported. Selected steel types are commonly used in boiler construction for superheaters and waterwalls – parts of a boiler that are most exposed to the high-temperature corrosion risk. The corrosion experiments were carried out under oxidizing conditions at 460 °C, 510 °C and 560 °C for 168 h. To determine the corrosion rate the mass of steel samples was measured after 24, 72 and 168 h. For a better understanding of the corrosion process, a detailed chemical analysis of ashes was conducted together with SEM-EDS analysis of the corrosion products. Ash melting and deposition behavior of both ashes were predicted according to 11 indices. It was found that cow dung and mixed straw ash differ significantly in terms of quantitative chemical compositions and ash melting characteristics. Cow dung ash is characterized by a high concentration of alkali compounds (2.57 wt% Cl, 30.6 wt% CaO, 5.56 wt% K2O) together with high phosphorus content typical for animal manure. The presence of alkali chlorides in the cow dung ash deposits led to a build-up of chlorides on the steel surface, which caused accelerated corrosion. At 560 °C the corrosion rate was over 3 times higher for cow dung ash than for mixed straw ash. The corrosion occurred due to the formation of low-melting FeCl2 mixtures since chlorine- and iron-rich particles were found in the crevices and cracks within deposits. The results clearly demonstrated the high corrosive potential of animal-origin biomass and therefore indicate the potential problems related to its thermal conversion process. These adverse effects can be reduced by ash removal and maintaining the temperature of the heating surfaces below 560 °C.

Processes based on generating vapor-phase hydroxyl radicals or chlorine radicals were developed for inactivating Listeria monocytogenes on mushrooms without negatively affecting quality. Antimicrobial radicals were generated from the UV-C degradation of hydrogen peroxide or hypochlorite and ozone gas. Response surface modeling was used to identify the interaction among the operating parameters for the hydroxyl radical process: UV-C254nm intensity, hydrogen peroxide concentration, and ozone delivered. There was an inverse relationship between hydrogen peroxide concentration and UV-C intensity in terms of the log reduction of L. monocytogenes. The independent parameters for the chlorine radical process were hypochlorite concentration, pH, and UV-C intensity. From predictive models, the optimal hydroxyl radical treatment was found to be 5% (v/v) H2O2, 2.86 mW/cm2 UV-C intensity (total UV-C dose 144 mJ/cm2), and 16.5 mg of ozone. The optimal parameters for the chlorine radical process were 10 ppm of hypochlorite (pH 3.0), 11.0 mg of ozone, and 4.60 mW/cm2 UV-C intensity. When inoculated mushrooms were treated with the optimal hydroxyl radical and chlorine radical processes, the reduction of L. monocytogenes was found to be 2.42 ± 0.42 and 2.61 ± 0.30 log CFU, respectively, without any negative effects on mushroom quality (weight loss and Browning index during 14 days of storage at 4°C). These reductions were significantly greater than those from application of the individual elements of the radical processes and those in the control process, which used a 90-s dip in 1% (v/v) hydrogen peroxide. The study has demonstrated that hydroxyl radical and chlorine radical vapor-phase treatments are equally effective at inactivating L. monocytogenes on mushrooms and can be considered as a preventative control step. HIGHLIGHTS

New complex compounds [Cd(μ-L1)2]n (I), [Cd(μ-L2)(μ-Cl)(μ-DMSO)]n (III), and [Cd2(μ-L2)(μ-Cl)3(μ-DMSO)DMSO/EtOH]n (IV) are synthesized by the reactions of 1-(4-methoxyphenyl)-1,4-dihydro-5H-tetrazole-5-thione (HL1) and 1-(2-methoxyphenyl)-1,4-dihydro-5H-tetrazole-5-thione (HL2) with cadmium chloride. The molecular and crystal structures of the complexes are determined by X-ray structure analysis (CIF files CCDC nos. 1993455 (I), 1869249 (III), and 1993497 (IV)). Complexes I, III, and IV have uniform polymeric structures. The О···Н, Cl···H, and C···S contacts are observed between 1D polymeric chains in the crystal cells of complexes I, III, and IV. Complexes III and IV contain DMSO molecules. Under other equivalent conditions, the reaction of HL1 or HL2 with cadmium chloride in ethanol affords complex I or II of different compositions. Complex II contains the chlorine atom as found by scanning electron microscopy, whereas no chlorine is observed in complex I according to the X-ray structure analysis data.

Filamentous fungi can enter drinking water supply systems in various ways, and exist in suspended or sessile states which threatens the health of individuals by posing a high risk of invasive infections. In this study, the biofilms formation kinetics of the three genera of fungal spores, Aspergillus niger (A. niger), Penicillium polonicum (P. polonicum) and Trichoderma harzianum (T. harzianum) isolated from the groundwater were reported, as well as the effects of water quality parameters were evaluated. In addition, the efficiency of low- concentrations of chlorine-based disinfectants (chlorine, chlorine dioxide and chloramine) on controlling the formation of fungal biofilms was assessed. The results showed that the biofilms formation of the three genera of fungi could be divided into the following four phases: induction, exponential, stationary and sloughing off. The optimum conditions for fungal biofilms formation were found to be neutral or weakly acidic at 28 °C with rich nutrition. In fact, A. niger, P. polonicum, and T. harzianum were not observed to form mature biofilms in actual groundwater within 120 hr. Carbon was found to have the maximum effect on the fungal biofilms formation in actual groundwater, followed by nitrogen and phosphorus. The resistance of fungal species to disinfectants during the formation of biofilms decreased in the order: A. niger > T. harzianum > P. polonicum. Chlorine dioxide was observed to control the biofilms formation with maximum efficiency, followed by chlorine and chloramine. Consequently, the results of this study will provide a beneficial understanding for the formation and control of fungal biofilms.

Disinfection of treated water is a necessary process. For this, chlorine and its products are widely used. During the treatment process, chlorine is added to drinking water as elemental chlorine, sodium hypochlorite solution or dry calcium hypochlorite. When applied to water, each of these forms “free chlorine”, which destroys pathogenic organisms. If adequate water treatment is not readily available, the impact on public health can be devastating. Worldwide, about 1.2 billion people lack access to safe drinking water, and about 2.4 billion people lack sanitation. As per WHO, 3.4 million people die from waterrelated diseases. Drinking water chlorination will remain a cornerstone of disinfection. This is because of the wide range of benefits provided by chlorine. However, alternative disinfectants including ozone and UV radiation are available, all disinfection methods have unique benefits, limitations and costs. So, an engineer has to consider all the pros and cons of a disinfectant method properly before deciding the one to adopt. Keywords: Disinfection, Gaseous Chlorination, Sodium Hypochlorite, Calcium Hypochlorite, Ultraviolet, Ozone, Chlorine dioxide

The samples used for serum electrolyte measurement should be analyzed immediately after being received in the laboratory within 1-2 hours to avoid an increase in the error of the results. Serum should be stored at 4°C for a period to prevent damage. The analyst should consider maximum delay time in the examination to maintain the serum's quality. This study compared the 2-hour and 3-hour delays in sodium (Na), potassium (K), and chlorine (Cl) tests. The method used in this study is an observational analysis with a cross-sectional study design. The samples in this study used 35 patient serum residues. The study was conducted in November 2020 with a continuous sampling technique. Electrolyte levels in the sample were measured by AVL 9180 Electrolyte Analyzer using Ion-Selective Electrode (ISE) method. The differences in electrolyte (Na, K, Cl) levels were analyzed by the Kruskal-Wallis Statistical test at a 95% confidence level. The results showed that the content of sodium, potassium, and chlorine were 0.719; 0.976; and 0.772. This study showed that there was no significant difference in the electrolyte content of sodium (Na), potassium (K), and chlorine (Cl) in the serum directly detected from the serum stored at 4°C for 2 hours and 3 hours. In conclusion, it is acceptable to postpone the serum test for 3 hours with various considerations.

Pool chemicals are utilized in pools to inactivate pathogens, optimize pH, and increase water clarity. This is conducted to ensure public health and safety by reducing bacteria concentrations and allowing distressed swimmers to be detected underwater. In commercial recreational facilities, muriatic acid and gaseous CO2 are typically used to maintain pH. Chlorine, which can take the form of liquid or solid tablets of sodium hypochlorite or granular calcium hypochlorite, is used to sanitize pool water, and is the most used chemical treatment in the world for swimming pools disinfection. If chlorine is mixed with muriatic acid, chlorine gas is formed, which can lead to severe injuries and fatalities (SIFs) to exposed individuals. This work illustrates an incident that occurred as a result of the simultaneous injection of muriatic acid and liquid sodium hypochlorite into a recreational natatorium chemical feed line. This led to the release of chlorine gas in the indoor environment, which resulted in injuries to five patrons. Furthermore, strategies are proposed to prevent this from occurring and to reduce the likelihood of similar incidents in the future. These include the implementation of fail-safe logic to prevent the controller from malfunctioning and ensuring that controller program settings do not permit simultaneous chemical injection.

Nitryl chloride (ClNO 2 ) is an important chlorine reservoir in the atmosphere that affects the oxidation of volatile organic compounds (VOCs) and the production of RO x radicals and ozone (O 3 ). This study presents measurements of ClNO 2 and related compounds at urban, polluted rural, and polluted lower tropospheric (mountaintop) sites in the winter of 2017–2018 over the North China Plain (NCP). The nocturnal concentrations of ClNO 2 were lower at the urban and polluted rural sites but higher at the polluted lower tropospheric site. The winter concentrations of ClNO 2 were generally lower than the summer concentrations that were previously observed at these sites, which was due to the lower nitrate radical (NO 3 ) production rate ( P (NO 3) ) and the smaller N 2 O 5 uptake coefficients ( γ (N 2 O 5) ) in winter, despite the higher ratios of dinitrogen pentoxide (N 2 O 5 ) to NO 3 in winter. Significant daytime peaks of ClNO 2 were observed at all the sites during the winter campaigns, with ClNO 2 mixing ratios of up to 1.3 ppbv. Vertical transport of ClNO 2 from the residual layers and prolonged photochemical lifetime of ClNO 2 in winter may explain the elevated daytime concentrations. The daytime-averaged chlorine radical (Cl) production rates ( P (Cl)) from the daytime ClNO 2 were 0.17, 0.11, and 0.12 ppbv h −1 at the polluted rural, urban, and polluted lower tropospheric sites, respectively, which were approximately 3–4 times higher than the campaign-averaged conditions. Box model calculations showed that the Cl atoms liberated during the daytime peaks of ClNO 2 increased the RO x levels by up to 27 %–37 % and increased the daily O 3 productions by up to 13 %–18 %. Our results provide new insights into the ClNO 2 processes in the lower troposphere impacted by fresh and intense anthropogenic emissions and reveal that ClNO 2 can be an important daytime source of Cl radicals under certain conditions in winter.

Crude sulfate turpentine (CST), a by-product of the kraft process, has commercial value that depends on the removal of sulfur compounds. The current study investigates desulfurization of CST using basic process steps for a paper mill at a pilot scale treatment. In another aspect, the sulfurous compounds in CST were removed by passing to the aqueous phase with terpin hydrate production, followed by α-terpineol conversion with citric acid catalysis. The goal was to design an environmentally friendly, low-cost, zero waste process and thereby refine the CST or byproducts to a quality that can produce chemical raw materials. Refining processes included hypochlorite oxidation, air oxidation, washing with water, and distillation. The sulfur content was decreased to 170, 106, and 29 ppm from respectively by 1260 ppm initial sulphur content of CST. The chlorine amount, due to treatment with hypochlorite oxidation, did not decrease with refining processes, even in distilled fraction. By obtaining α-terpineol from terpin hydrate, the sulfur compounds were completely removed. According to the GS-MS analysis results, distilled sulfate turpentine (DST) as the final product of the refining process of the CST sample increased the ratio with pinenes. On the other hand, with two reaction steps by obtaining terpin hydrate from CST and then α-terpineol, pinenes were converted to α-terpineol.

Higher efficient reverse osmosis (RO) membrane development is a significant issue due to the payoff among salt rejection and water flux and permissive chlorine attacking and fouling potential. Weak chlorine resistance is a distinctive challenge for composite polyamide thin-film reverse osmosis membranes. A commercial aromatic membrane was modified by grafting nitrogen-doped graphene oxide quantum dots (N-GOQDs) to enhance chlorine resistance, embedding two-dimensional MXene Ti3C2Tx, introducing synthetically reductive thioether units and oxidized graphitic carbon nitride (OGCN). In this work, salt rejection, chlorine resistance, and water flux increased compared to the pristine membrane. Comprehensive arrangement of desalination performance and chlorine resistance was achieved by varying time and concentrations of prepared chemicals. For instance, improved chlorine resistance, after 12 hours of grafting time by N-GOQDs doped membrane, was 32.8%, after 6 hours of exposure time by MXene Ti3C2Tx membrane was 27.4%, after 1 hour of exposure time by thioether membrane was 28.1% and after 40 hours of doping time by OGCN membrane was 31.3%. N-GOQDs doped membrane showed a good chlorine resistant property, but on the other hand, thioether nano units showed other properties more effectively, including water flux, salt rejection, and less reaction time.

The results of the Rehbinder effect manifestation during testing of superalloys in contact with corrosive media containing Na2SO4 + NaCl are discussed. We present the experimental study of the effect of salts containing chlorine and sulfur on the mechanical properties and long-term strength of single crystal and powder nickel-based superalloys at high temperatures. The practical value of the work is associated with the possible operation of gas turbine parts in conditions of ingress of the particles containing chlorine, sulfur and sodium into the flow path. A simplified (compared to a previously used) procedure of testing wrought alloys for long-term strength in molten salts is developed. A comparative study of the mechanical properties and long-term strength of a single crystal superalloy in the initial state (previously damaged by corrosion of different duration) and being in contact with salts during testing is carried out. Due to the large scatter of experimental data, the method of lower envelopes has been proposed and implemented to determine the guaranteed values of the long-term strength. It is shown that the guaranteed values of the long-term strength at different temperatures and test durations can decrease by 2.5 – 5.0 times in the presence of salts. Metallographic studies of the nature of damage and destruction of samples are carried out. The revealed decrease in the long-term strength of heat-resistant alloys in contact with salts is interpreted as the Rehbinder effect and not as a manifestation of the effect of stress corrosion cracking. A methodology for using the obtained test results with a duration of up to several thousand hours in highly aggressive environments is proposed to predict the long-term strength in relation to long-term operation (tens of thousands of hours) under conditions of relatively low salt loads.

The increasing use of chlorine- or chloramine-containing irrigation waters to minimize foodborne pathogens is raising concerns about the formation and uptake of disinfection byproducts into irrigated produce. Chlorate has received particular attention in the European Union. While previous research demonstrated the formation of chlorate from dark disproportionation reactions of free chlorine and uptake of chlorate into produce from roots, this study evaluated chlorate formation from solar irradiation of chlorine- and chloramine-containing irrigation droplets and uptake through produce surfaces. Sunlight photolysis of 50 μM (3.6 mg/L as Cl2) chlorine significantly enhanced the formation of chlorate, with a 7.2% molar yield relative to chlorine. Chlorate formation was much less significant in sunlit chloramine solutions. In chlorinated solutions containing 270 μg/L bromide, sunlight also induced the conversion of bromide to 280 μg/L bromate. Droplet evaporation and the resulting increase in chlorine concentrations approximately doubled sunlight-induced chlorate formation relative to that in the bulk solutions in which evaporation is negligible. When vegetables (broccoli, cabbage, chicory, lettuce, and spinach) were sprayed with chlorine-containing irrigation water in a sunlit field, sunlight promoted chlorate formation and uptake through vegetable surfaces to concentrations above maximum residue levels in the European Union. Spraying with chloramine-containing waters in the dark minimized chlorate formation and uptake into the vegetables.

Chlorination and carbochlorination processes have industrial applications in metallurgical activity for extraction and purification of uncommon metals such as rare earth elements (REE). This study reviews the chlorination and carbochlorination reactions of light REE (LREE) oxides with chlorine considering the thermodynamic, stoichiometric, and kinetic aspects of the reactions. Lanthanides between lanthanum to gadolinium were considered as LREE, in agreement with previous literature, and the results were detailed in this review. LREE were analyzed taking into account their oxidation states and were divided into three groups accordingly. The results presented show that, although the LREE are chemically similar, their behaviors during the reactions with Cl2 and Cl2–C, and the different LREE-O–Cl compounds formed, have particularities. It was observed that gadolinium, in both thermodynamic calculations and experimental results, presents some differences, and it can be considered intermediate between light and heavy REE; i.e., reactions between LREE2O3 and Cl2(g) begin at approximately 250 °C, except for Gd2O3 that begins at 327 °C. The present work will contribute to a better understanding of the chemistry of LREE oxides and Cl2 under different conditions and the products obtained in the LREE–O––Cl2(g) and LREE–O–C–Cl2(g) systems.

There is growing interest in the fate and effects of transformation products generated from emerging pollutant classes, and new tools that help predict the products most likely to form will aid in risk assessment. Here, using a family of structurally related steroids (enones, dienones, and trienones), we evaluate the use of density functional theory to help predict products from reaction with chlorine, a common chemical disinfectant. For steroidal dienones (e.g., dienogest) and trienones (e.g., 17β-trenbolone), computational data support that reactions proceed through spontaneous C4 chlorination to yield 4-chloro derivatives for trienones and, after further reaction, 9,10-epoxide structures for dienones. For testosterone, a simple steroidal enone, in silico predictions suggest that C4 chlorination is still most likely, but slow at environmentally relevant conditions. Predictions were then assessed through laboratory chlorination reactions (0.5-5 mg Cl2/L) with product characterization via HRMS and NMR, which confirmed near exclusive 4-chloro and 9,10-epoxide products for most trienones and all dienones, respectively. Also consistent with computational expectations, testosterone was effectively unreactive at these same chlorine levels, although products consistent with in silico predictions were observed at higher concentrations (in excess of 500 mg Cl2/L). Although slight deviations from in silico predictions were observed for steroids with electron-rich substituents (e.g., C17 allyl-substituted altrenogest), this work highlights the potential for computational approaches to improve our understanding of transformation products generated from emerging pollutant classes., Environmental Science & Technology, 55 (21), ISSN:0013-936X, ISSN:1520-5851

Dimensionally stable anodes (DSAs) are regarded to be optimized electrodes for electrochlorination owing to their excellent electrocatalytic activity for the chlorine evolution reaction (CER). However, in dilute chloride solutions, DSAs preferentially produce oxygen rather than chlorine because of their low overpotential for oxygen evolution reaction (OER). Considering the frequent use of electrochlorination in dilute conditions, the poor efficiency of DSAs severely limits their environmental and industrial applications. Therefore, the aim of this study is to improve the CER efficiency of IrO2 in dilute chloride solutions with the addition of Fe2O3 as a co-catalyst which has a slow reaction rate of OER. In a dilute chloride solution of 1 mM NaCl, Ir0.11Fe0.25O0.64 showed a far higher current efficiency for CER (28%) than that of IrO2 (3%). Ir0.11Fe0.25O0.64 also exhibited better current efficiency in NaCl solution of various concentrations (1 mM to 2 M) than that of IrO2. This is attributed to the synergistic effect of Fe2O3 (slow OER rate) and IrO2 (fast CER rate). Moreover, the long-term stability of Ir0.11Fe0.25O0.64 was demonstrated with tap water electrolysis for 50 days. These results suggest that Ir0.11Fe0.25O0.64 has great potential to expand the scope of application of the electrochlorination system, particularly in dilute solutions.

Summary Amides and olefins are cheap and readily available industrial materials. Hence, the synthesis of oxazolines from amides and olefins is significant. Regio- and site-selective amino-oxygenation of olefins is one of the most desirable transformations for important oxazoline derivatives, which are common motifs in pharmaceuticals, natural products, agrochemicals, and chiral ligands. However, strong oxidants and iodine reagents create challenges for its applications in organic synthesis. Here, we demonstrate an electrochemical (3 + 2) cyclization between amides and olefins. Various oxazolines are delivered in good yields and with excellent site selectivity and diastereoselectivity simultaneously. Mechanistic studies indicate that chlorine anions, generated from inexpensive 1,2-dichloroethane by cathodic reduction, can be oxidized on the anode and react with alkenes to generate chloronium species, which are key intermediates for this electrochemical cyclization.