Ratio Of Chlorine Research Articles

Chloride Vapor Annealing for Efficient Deep-Blue Perovskite Light-Emitting Diodes.

Achieving deep-blue emission is crucial for the practical application of perovskite light-emitting diodes (LEDs) in displays. Increasing the ratio of chlorine to bromine in the perovskite is a facile method to achieve deep-blue emission. However, the low solubility of chloride in the perovskite precursor solution and the low formation energy of defects present challenges that limit device efficiency. Here, we demonstrate a chloride vapor annealing method utilizing ethylammonium chloride (EAC) to enable in situ halide exchange and defect passivation. We find that the chloride ions from EAC can effectively exchange with the bromide ions in the perovskite, resulting in blue-shifted emission. Additionally, the ammonium group in EAC can coordinate with unsaturated lead, reducing trap-assisted nonradiative recombination. Based on this approach, we achieve efficient deep-blue perovskite LEDs with a peak external quantum efficiency of 6.8% and color coordinates of (0.131, 0.044), which fully meet the Rec. 2020 blue standard.

Continuous Monitoring of Monochloramine in Water, and Its Distinction from Free Chlorine and Dichloramine Using a Functionalized Graphene-Based Array of Chemiresistors.

Monochloramine (MCA) is commonly added to drinking water as a disinfectant to prevent pathogen growth. The generation of MCA at the treatment plant requires tight control over both pH and the ratio of free chlorine (FC) to ammonia to avoid forming undesirable byproducts such as dichloramine (DCA) and trichloramine (TCA), which can impart odor and toxicity to the water. Therefore, continuous monitoring of MCA is essential to ensuring drinking water quality. Currently, standard colorimetric methods to measure MCA rely on the use of reagents and are unsuitable for online monitoring. In addition, other oxidants can interfere with MCA measurement. Here, we present a solid-state, reagent-free MCA sensing method using an array of few-layer graphene (FLG) chemiresistors. The array consists of exfoliated FLG chemiresistors functionalized with specific redox-active molecules that have differential responses to MCA, FC, and DCA over a range of concentrations. Chemometric methods were employed to separate the analytes' responses and to generate multivariate calibration for quantification. A minimum of three sensors are required in the array to maintain full functionality. The array has been demonstrated to quantify MCA in buffered and tap water as a low-cost, reagent-free approach to continuous monitoring.

Energy Optimization through Heat and Power Integration on a Chlorobenzenes Production Plant

In this research work, an attempt has been made to address the heat and power integration opportunities for the process of the chlorination of benzene. This process produces a mixture of chlorobenzenes. To increase the production of the dichlorobenzene portion, the ratio of chlorine to benzene is typically 2:1. A process simulation model is designed using Aspen Plus for the production of 70,000 tons/year of dichlorobenzene via the reaction of liquid benzene with gaseous chlorine. Energy analysis is performed for the effective utilization of the utilities by networking the heat exchangers. This modification reduced the process heating and cooling requirements by 56.7% and 12.7%, respectively, and a reduction by 35.4% in the operating costs is achieved, while the annualized fixed cost increased by 9.6%; these changes resulted in savings in the total annual costs of about 10.9%.

A New Sample Processing Protocol for Separation and Purification Enabling Precise Analysis of Various Non-Traditional Isotopes in Geological Samples with Low Concentrations

Many non-traditional isotopes, such as chlorine, magnesium, calcium, etc., are widely used as groundwater tracers. A new sample processing protocol of purification and concentration for isotopic analysis is presented to overcome many of the major drawbacks of existing methods. Contemporary sample preparation often requires several laborious off-line procedures in a ultra clean laboratory prior to instrumental determination; additionally, interference ions in real samples are difficult to completely remove, especially when the concentration of those ions is equal to that of the target ions. The new protocol includes the following steps: (i) one-step purification using a newly developed isotopic preparative chromatograph (IPC) with a background suppressed mode to obtain extremely pure components that only have target ions and H2O; (ii) enrichment of the collected pure solution from the previous step using a newly developed ultra clean concentrator filled with high purity nitrogen; (iii) transforming the enriched target ion into suitable speciation inside the ultra clean concentrator; (iv) finally, sending the enriched solutions to a multi-collector inductively coupled-plasma mass-spectrometer (MC-ICP-MS) or thermal ionization mass spectrometer (TIMS). The present method was validated using certified reference materials and real samples for both chlorine and magnesium; the precision of chlorine ratio value was generally below 0.22‰ and that of Mg was below 0.12‰. This processing protocol provides a potential method for isotope sample preparation and analysis in a small number of geological samples with low concentrations of many other elements or compounds such as nitrate, sulfate, lithium, calcium, strontium, etc.

Monte Carlo simulations of the underwater detection of illicit war remnants with neutron-based sensors

In recent years, the demand for accurate detection and identification of hazardous substances in an aquatic environment, especially in the Baltic Sea, has seen a significant rise, with a specific focus on unexploded ordnance (UXO) containing conventional explosives and various chemical agents, including, but not limited to, mustard gas, Clark I and II and other lethal compounds. These substances pose a significant threat to human health and the environment, and their identification is crucial for effective demining and environmental protection efforts. In this article, a novel approach for fast, remote, and non-destructive recognition of dangerous substances based on a SABAT sensor installed on an ROV is described. The performance of the proposed neutron-based sensor in an aquatic environment was verified based on a series of Monte Carlo simulations for mustard gas, Clark I and II, and TNT, as they are the most common chemical threats at the bottom of the Baltic Sea. The sensor’s ability to accurately discriminate hazardous and non-hazardous materials is described in the paper in terms of the ratio of chlorine to hydrogen (Cl/H), carbon to oxygen (C/O), and nitrogen to hydrogen (N/H) activation lines integrals. The authors also discussed the future directions of work to validate SABAT (Stoichiometry Analysis By Activation Techniques) sensors in the operational environment.

The ways of using collector drainage waters for irrigation

For the conditions of Uzbekistan, it is necessary to maintain the reclamation condition of irrigated lands constantly and increase soil fertility. It is necessary to study the land reclamation condition in our region. An important factor is that collector-drainage waters are used for irrigation to pay off the shortage of water resources. The object of the study is the collector-drainage waters formed in the Republic of Uzbekistan. The article presents research on the method of statistical data processing, materials analysis, field research, and computer plotting curves and diagrams. As a result of the irrational use of collector-drainage waters, secondary clogging is observed in some areas. Data analysis was carried out from 2005 to 2020. The analysis of long-term studies shows that by 2020 there was a decrease in highly saline lands, which makes 83 thousand hectares. Whereas in 2005, saline lands made up 160 thousand hectares. Also, data analysis shows that areas with different mineralization are almost unchanged and need to develop scientifically based measures. The purpose and objectives of scientific research are to study irrigation with collector-drainage waters, their impact on the reclamation state of irrigation lands, and assess their suitability for irrigation. To increase the reliability of assessments of the quality of collector-drainage waters under various natural and economic conditions, it is recommended to use the relationship between water mineralization and the ratio of chlorine to sulfate. The dependence was built on the results of long-term data on the hydrochemical regime of collector-drainage waters. Estimates of our research have shown that at least 50% of the collector-drainage runoff is suitable for use in places of formation in Uzbekistan. Collector-drainage waters have mainly a sulfate type of salinity, and such waters with mineralization of 2-3 g/l, such waters with mineralization of 2-3 g/l can be used for repeated irrigation. To cover the shortage of irrigation water, drainage waters with increased mineralization by diluting them with fresh water will also be used for reuse.

Controllable synthesis of a carbonaceous pitch from molecular dimension by a novel method of chlorination-dechlorination

The carbonaceous pitch derived from coal liquefaction residue was controllably synthesized from the molecular dimension with a novel method, chlorination–dechlorination. The factors affecting the qualities of chlorination–dechlorination derived pitch, including chlorine ratios, were studied. The qualities of the pitches prepared with chlorination–dechlorination and the conventional thermal condensation method are compared. The carbons in the prepared carbonaceous pitch mainly exist in aromatic structures, which are oligomerized to transform dimers and trimers by chlorination–dechlorination. The C/H ratio, average molecular weight, and carbon aromaticity are increased by chlorination–dechlorination. According to the result of the simulation, the hydrogen atoms on the side chain of aromatic compounds are easier to be mono-substituted by chlorine atoms during chlorination, and then the substituting chlorine atoms connect with other hydrogen atoms to form to escape out of the reactor in the formation of hydrogen chloride during dechlorination, making the aromatic compounds oligomerize with each other. Thus, the conclusion that the chlorinated pitch has a more linear and cross-linking molecular structure is demonstrated, which is also confirmed by the results of 13C NMR. The pitch precursors exhibit better thermal stability and thermochemical property even when the softening point has been raised to around 230 ℃ owing to the linear and cross-linking molecular structure. In addition, the pitches synthesized by the method of chlorination–dechlorination shows a more homogeneous state, while the pitch produced by thermal condensation contains a small number of powdery coke particles, and they also possess more excellent spinnability and appropriate viscosity for the process of melt-spinning. Chlorination–dechlorination can be used to achieve the controllable synthesis of the carbonaceous pitch from the molecular dimension. The properties of derived pitches are better as the addition of chlorine increases.

Comparison of Disinfection By-Product Formation and Distribution during Breakpoint Chlorination and Chlorine-Based Disinfection in Drinking Water

Breakpoint chlorination (BC) and disinfection with chlorine-based disinfectant are widely used procedures in drinking water production. Both involve dosing chlorine into the raw water, where it can react with organic compounds, forming disinfection by-products (DBPs) of health concern. However, technological parameters (e.g., contact time, chlorine dosage, and bromide to residual free chlorine ratio) of the two chlorination procedures are different, which can lead to differences in DBP formation. To better understand this, a year-long sampling campaign was carried out at three waterworks in Hungary, where both BC and chlorine disinfection are used. To confirm the results of the field sampling, bench-scale experiments were carried out, investigating the impact of (a) bromide concentration in raw water, (b) residual free chlorine (bromide to residual chlorine ratio), and (c) contact time on DBP formation. The measured DBPs were trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and chlorate. During BC, the DBPs were formed in higher concentration, with the exception of one waterwork having elevated bromide content in the raw water. Bromine substitution factors (BSFs) were significantly higher during disinfection than BC in both field and laboratory experiments. After BC, the chlorate concentration range was 0.15–1.1 mg/L, and 96% of the samples exceeded the European Union (EU) parametric value (0.25 mg/L), whereas disinfection contributed only slightly. Granular activated carbon (GAC) filters used to remove DBPs in waterworks were exhausted after 6–8 months of use, first for those chlorinated THMs, which are generated predominantly during BC. The biological activity of the filters started to increase after 3–6 months of operation. This activity helps to remove the biodegradable compounds, such as disubstituted haloacetic acid (DHAAs) and HANs, even if the adsorption capacity of the GAC filters are low.

Nitrite-enhanced N-nitrosamines formation during the simulated tetracycline polluted groundwater chlorination: Experimental and theoretical investigation

N-nitrosamines (NAs), a class of emerging nitrogenous disinfection byproducts, have been detected remarkably in drinking/reclaimed water. There is a significant risk of excessive levels of NAs in the chlorination of the polluted source water, especially in the direct chlorination of nitrite-enriched groundwater. Considering the co-pollution of nitrite and micro-organic pollutants on groundwater, experiments were conducted on chlorination of nitrite-enriched water with precursor of antibiotics, and it was confirmed that the Cl 2 : N (molar ratio of chlorine to nitrite), contacting time, pH, and DO appreciably influenced the NAs formation potential. The molecular electric potential revealed that different dissociation status of precursors has a specific correlation with NAs formation potential (FP). The nitrite significantly increased the NAs FP because the reactive nitrogen species (RNS) formed in the oxidation process from nitrite to nitrate. Sequences of transformation products are determined to support the RNS promoted hypothesis of N-nitrosodimethylamine (NDMA) formation mechanism; furthermore, theoretical investigation in the reaction of dimethylamine (DMA) with different RNS verified the above hypothesis. • NDMA FP significantly promoted in chlorination of nitrite-enriched groundwater. • DO is not a key factor to NDMA formation in nitrite-enriched situation. • RNS enhanced-nitrosation pathway was proposed. • NDEA has been detected along with NDMA formation.

Isotopic discrimination of natural and anthropogenic perchlorate sources in groundwater in a semi-arid region of northeastern Oregon (USA)

Perchlorate (ClO4−) has synthetic and natural sources. Synthetic ClO4− is released to the environment from its use as an oxidant in military and aerospace applications, and from its presence in a variety of common commercial products, such as safety flares, chlorate herbicides, and fireworks. Natural sources of ClO4− in the environment include imported nitrate fertilizers derived from salt deposits in the Atacama Desert of Chile and indigenous natural ClO4− that accumulates in unsaturated soils and groundwaters in other arid and semi-arid environments, largely from atmospheric deposition. The stable isotope ratios of chlorine (37Cl/35Cl) and oxygen (18O/16O, 17O/16O) and the isotopic abundance of radioactive 36Cl in ClO4− can be used to discriminate these different sources. Perchlorate was previously detected at relatively high concentrations (3.8–34.7 μg/L) in groundwater from many wells in the Boardman-Umatilla area near the Columbia River in northeastern Oregon, which is a semi-arid, highly agricultural, heavily irrigated area that includes several past and current military installations. Eight representative groundwater wells were sampled throughout this region and isotopic characteristics of ClO4− collected from each well were measured along with other chemical and isotopic parameters including tritium and other groundwater age indicators. Isotopic data indicate that indigenous natural ClO4− was present in groundwater from all sampled wells and was the predominant source in five of the wells. Synthetic ClO4− was present in the three remaining wells with natural ClO4−, and a minor fraction of Atacama-fertilizer-derived ClO4− was indicated in one of the wells. Data from this study expand the geographic area of the USA in which indigenous natural ClO4− has been detected to include the semi-arid northwest. This study also illustrates the role of irrigation recharge as a mechanism for producing relatively high concentrations of indigenous natural ClO4− in groundwater by flushing accumulated salts from the unsaturated zone.

Formation of iodinated aromatic DBPs at different molar ratios of chlorine and nitrogen in iodide-containing water

Variations in iodinated aromatic disinfection byproducts (DBPs) in the presence of I− and organic compounds as a function of reaction time in different molar ratios (MRs) of HOCl:NH3-N were investigated. Up to 17 kinds of iodinated aromatic DBPs were identified in the breakpoint chlorination of iodide (I−)/organic (phenol, bisphenol S (BPS) and p-nitrophenol (p-NP)) systems, and the possible pathways for the formation of iodinated aromatic DBPs were proposed. The reaction pathways include HOCl/HOI electrophilic substitution and oxidation, while the dominant iodinated DBPs were quantified. In the I−/phenol system (pH = 7.0), the sum of the concentrations of four iodinated aliphatic DBPs ranged from 0.32 to 1.04 μM (triiodomethane (TIM), dichloroiodomethane (DCIM), diiodochloromethane (DICM) and monoiodoacetic acid (MIAA)), while the concentration of 4-iodophenol ranged from 2.99 to 12.87 μM. The concentration of iodinated aromatic DBPs remained stable with an MR = 1:1. When the MR was 6:1, iodinated aromatic DBPs decreased with increasing reaction time, in which the main disinfectant in the system was active chlorine. This study proposed the formation mechanism of iodinated aromatic DBPs during the breakpoint chlorination of iodide-containing water. These results can be used to control the formation of hazardous iodinated aromatic DBPs in the disinfection of iodine containing water.

Harvest timing and potassium doses on post-harvest quality of dwarf-green coconut water

Coconut is an expressive culture in tropical climate regions and its yield and fruit quality is directly linked to several factors, such as climatic conditions, fertilizer management, harvesting fruits period and other factors. Aiming to evaluate post-harvest of irrigated green dwarf coconut water quality due to potassium doses and different harvesting time, an experiment was carried out at the Federal Rural University of the Semi-Arid - UFERSA from January to November 2015. The experimental design was split-plot randomized blocks. Plots were 5 potassium doses (0, 150, 300, 450 and 600 g plant-1) and the subplots 4 harvesting time of fruits (5, 6, 7 and 8 months after the opening of the inflorescence), 4 blocks and 2 plants for a total of 40 treatment plants. The experimental area consisted of coconut trees of green dwarf variety with four years old. Were evaluated the titratable acidity, soluble solids, ratio, electrical conductivity, pH, total sugar and levels of potassium, calcium, magnesium, sodium and chlorine from coconut water. Under the conditions studied, higher doses of potassium decreased qualitative characteristics of coconut water, the absence of potassium fertilization coconut trees had better results. The optimal harvest time is between 6 and 7 months old.

THE FORMATION MECHANISMS OF COMPOSITION OF DRINKING GROUNDWATER OF THE Kyiv DEPOSIT (ON THE EXAMPLE OF THE OBOLON WATER INTAKE STRUCTURE)

This paper presents the results of the assessment of interactions in the water-rock system using an integrated approach including the balance method and the method of geochemical (thermodynamic) modelling. Assessment is carried out for conditions of Cenomanian-Callovian and Bajocian aquifers within the Obolon groundwater intake structure in Kyiv. The results obtained demonstrate that groundwater of the Cenomanian-Callovian and Bajocian aquifers within the Obolon groundwater intake structure differ in chemical composition, physicochemical conditions, and especially in the formation of water composition due to the interactions in the water-rock system. This paper proposes division of water into groups, taking into account both the features of chemical composition and its formation process. The water group characterized by anomalous ratio of chlorine and sodium is distinguished, as well as the possible formation mechanism of this water composition is proposed. The chemical composition of the waters of both aquifers meets the requirements of Ukrainian legislation for drinking water quality (GSanPiN 2.2.4-171-10). Groundwater quality of the Cenomanian-Callovian complex is shown to be higher than that of the Bajocian aquifer. For both aquifers, the water of higher quality is the one with cationic composition determined largely by ion exchange. The ion exchange processes can be controlled to a certain extent by regulating the water withdrawal from the wells, and hence the water quality can be regulated in this way as well. Another way to regulate water quality could be the mixing of water from two aquifers during water treatment, which would, on the one hand, compensate the insufficient water quality of individual aquifers and, on the other hand, provide for continuous well operation contributing to the maintenance of more or less stable physicochemical processes. However, these hypotheses require further detailed consideration and, if confirmed, a detailed justification of their feasibility.

Behavior of magnesium impurity during carbochlorination of magnesium-bearing titanium slag in chloride media

Abstract In this study, the phase composition, morphology, and element distribution of Mg impurities in a low-grade titanium slag and in its chlorinated residue after carbochlorination were identified using XRD, SEM-EDS, and MLA. Most Mg impurities existed as anosovite, rutile, titanaugite, and Ti silicate phases before the carbochlorination process. The thermodynamic analysis revealed that the chlorination tendencies of Mg, Ti, Ca, Fe, and Mn oxides in the original titanium slag was much higher than those of Si and Al oxides in the temperature range of 700–850 °C. In addition, the binary phase diagram analysis indicates that the magnesium chloride (MgCl2) byproduct formed Na2MgCl4 eutectic salts in the NaCl-based salt bath. The carbochlorination experiments of the Mg-bearing titanium slag show that the chlorination ratio of magnesium oxide was above 93% under the suitable industrial conditions used for the extraction of titanium from Mg-bearing titanium slag. In addition, the formation of Na2MgCl4 eutectic salts after carbochlorination was confirmed, indicating that the negative effect of MgCl2 on the chlorination process was effectively eliminated. The Mg impurities in the chlorinated residue existed as titanaugite, quartz, chlorite, and rutile phases. Furthermore, we found that the carbochlorination of Mg-bearing titanium slag in chloride media effectively improved the comprehensive utilization efficiency of the Mg-bearing titanium slag. We believe that the proposed carbochlorination mechanism of the Mg-bearing titanium slag will provide thorough understanding and useful guidance on the practical industrial application of Mg-bearing titanium slag.

Control modules in the “Intelligent building” system

The relevance of the article consists on the use of telemetry control modules to organize the uninterrupted operation for dispatching service, including remote work. Thanks to telemetric means of dispatching control and management of the conditions of water supply facilities, the process is reaching a new qualitative level. The functionality of the water intake unit has been significantly improved as a result of the introduction of a telemetry and telecontrol system in the form of separate technological modules. The developed modules provide additional functions for water quality control, including residual chlorine, accounting for a number of random pollution factors in addition to the route technology of the dispatching system; remote control of executive mechanisms with the possibility of automatic control; self- diagnostics of the software and hardware complex, as well as planning of preventive and repair work of engineering systems. The results of water quality on-line monitoring by using a telemetry module in the chlorination room automatically providing the optimal ratio of chlorine added to the water are presented.

Formation Chlorine Measurement From Spectroscopy Enables Water Salinity Interpretation: Theory, Modeling, and Applications

Many methods of calculating water saturation require knowing the chloride concentration in formation water. Chlorides have a strong effect on water properties, and they impact saturation estimates that are based on resistivity, dielectric dispersion, or thermal neutron absorption. Here we introduce a new direct quantitative measurement of formation chlorine from nuclear spectroscopy, enabling a continuous log of water salinity within a limited radial depth. Neutron capture spectroscopy is sensitive to chlorine and is a natural fit for measuring its concentration, except that the spectrum contains chlorine from both the formation and borehole. The borehole chlorine background can be large and is highly variable. Historical efforts to derive water salinity from spectroscopy have relied on ratios of chlorine and hydrogen, which are affected by the borehole and hydrocarbons. The direct use of chlorine provides a more reliable basis for salinity interpretation after isolating its formation signal. We partition the borehole and formation components of chlorine via two unique spectral standards. The contrast between the two standards arises from differences in gamma ray scattering based on their point of origin. The shape of the borehole chlorine standard must be adjusted along depth to account for environmentally dependent scattering, which we achieve with a continuously varying function of borehole and formation properties. The algorithm is derived from 129 laboratory measurements and 2,995 numerical simulations spanning a diverse range of conditions. The remaining signal is converted into a log of formation chlorine concentration. In combination with total porosity, chlorine concentration sets a minimum value for water salinity. Adding an organic carbon measurement enables the simultaneous estimation of water volume and salinity. Chlorine concentration can also be combined with a selected water salinity to compute a water volume for comparison with other methods. Finally, chlorine concentration enables calculation of a maximum expected sigma, which can identify the presence of excess thermal absorbers in the matrix. The systematic uncertainty on the chlorine concentration ranges from 0.03 to 0.07 wt%, depending on borehole size. The resulting salinity accuracy is inversely proportional to porosity. A potential limitation of the measurement is its depth of investigation, reaching 8 to 10 in. for 90% of the signal. The chlorine concentration is sensitive to filtrate or connate water, depending on formation permeability and invading fluids. We first present the technique to measure formation chlorine, supported by modeling, laboratory data, and core-log comparisons. We then propose petrophysical workflows to interpret the chlorine concentration.

Characterization of metal concentration, heavy metal elution, and desalination behavior of municipal solid waste incineration bottom and grate sifting deposition ash based on particle size

Resource and environmental safety protocols of incineration residues were evaluated by analyzing the metal concentration, heavy metal elution, desalination behavior, and chlorine removal ratio owing to particle size differences between bottom ash (BA) and grate sifting deposition ash (GA). In the total content test, Cl, Zn, and Cr in the incinerator BA exceeded the cement acceptance standard (Cl: 1000 mg/kg; Zn: 1700 mg/kg, and Cr: 170 mg/kg) at almost all of the particle sizes, while Au, Ag, Pd, and Zn had high contents in the GA. When using BA as a construction material, heavy metal elution values and contents are restricted as per the product quality standards based on the Japanese soil pollution control law. Lead within the BA and GA exceeded the standard values for most particle sizes. We predicted that there would be a limit on the elution of K by only washing with water. The removal ratio of total chlorine by particle size was approximately 20–70%, where the effect of the particle size on the removal ratio was small, suggesting that the elution of chlorine was complete in approximately 6 hours. These results contribute to information on the recycling of BA and GA.

Formation of disinfection by-products in a UV-activated mixed chlorine/chloramine system

In recent years, ultraviolet (UV) irradiation coupled with chlor(am)ination process is ubiquitous in secondary water supply systems in many cities of China. However, the disinfection by-products (DBPs) formation in a UV-activated mixed chlorine/chloramine system (MCCS) still remains unclear. In this study, the DBPs formation in a UV-activated MCCS was systematically investigated, considering influencing factors including the mass ratios of free chlorine to NH2Cl, UV irradiation, pH values, NOM types, Br− concentration and toxicity of the DBPs. Results indicated that DBPs formation decreased remarkably as mass ratio of free chlorine to NH2Cl changed from 5:0 to 0:5. The DBPs formation in humic acid (HA)-containing water was the highest, followed by those in fulvic acid (FA) and algal organic matter (AOM). Besides, better control of the DBP-related calculated toxicity can be achieved in acidic conditions regardless of the UV irradiation. Furthermore, in the presence of Br−, a significant reduction of DBPs formation could be achieved in a UV-activated MCCS. The findings also demonstrated that DBPs formation in real water can be effectively reduced at high UV fluence in a MCCS.

Lithium and Chlorine-Rich Preparation of Mechanochemically Activated Antiperovskite Composites for Solid-State Batteries.

Assembling all-solid-state batteries presents a unique challenge due to chemical and electrochemical complexities of interfaces between a solid electrolyte and electrodes. While the interface stability is dictated by thermodynamics, making use of passivation materials often delays interfacial degradation and extends the cycle life of all-solid cells. In this work, we investigated antiperovskite lithium oxychloride, Li3OCl, as a promising passivation material that can engineer the properties of solid electrolyte-Li metal interfaces. Our experiment to obtain stoichiometric Li3OCl focuses on how the starting ratios of lithium and chlorine and mechanochemical activation affect the phase stability. For substantial LiCl excess conditions, the antiperovskite phase was found to form by simple melt-quenching and subsequent high-energy ball-milling. Li3OCl prepared with 100% excess LiCl exhibits ionic conductivity of 3.2 × 10−5 S cm−1 at room temperature, as well as cathodic stability against Li metal upon the extended number of cycling. With a conductivity comparable to other passivation layers, and stable interface properties, our Li3OCl/LiCl composite has the potential to stably passivate the solid-solid interfaces in all-solid-state batteries.

Mechanistic study on chlorine/nitrogen transformation and disinfection by-product generation in a UV-activated mixed chlorine/chloramines system

The conversion mechanisms of chlorine species (including free chlorine, monochloramine (NH2Cl), dichloramine, and total chlorine), nitrogen species (including ammonium (NH4+), nitrate (NO3−), and nitrite (NO2−)) as well as the formation of disinfection by-products (DBPs) in a UV-activated mixed chlorine/chloramines system in water were investigated in this work. The consumption rates of free chlorine and NH2Cl were significantly promoted in a HOCl/NH2Cl coexisting system, especially in the presence of UV irradiation. Moreover, the transformation forms of nitrogen in both ultrapure and HA-containing waters were considerably affected by UV irradiation and the mass ratio of free chlorine to NH2Cl. NO3− and NO2− can be easily produced under UV irradiation, and the removal efficiency of total nitrogen with UV was obvious higher than that without UV when the initial ratio of HOCl/NH2Cl was less than 1. The roles of different radicals in the degradation of free chlorine, NH2Cl and NH4+ were also considered in such a UV-activated mixed chlorine/chloramines system. The results indicated that OH• was important to the consumption of free chlorine and NH2Cl, and showed negligible influence on the consumption of NH4+. Besides, the changes of DOC and UV254 in HA-containing water in UV-activated mixed chlorine/chloramines system indicated that the removal efficiency of DOC (24%) was much lower than that of UV254 (94%). The formation of DBPs in a mixed chlorine/chloramines system was also evaluated. The yields of DBPs decreased significantly as the mass ratio of HOCl/NH2Cl varied from 1 : 0 to 0 : 1. Moreover, compared to the conditions without UV irradiation, higher DBPs yields and DBP-associated calculated toxicity were observed during the UV-activated mixed chlorine/chloramine process.