Artigos de revistas: "Chlorination"

1

Liu, Shiyuan, Weihua Xue e Lijun Wang. "Extraction of the Rare Element Vanadium from Vanadium-Containing Materials by Chlorination Method: A Critical Review". Metals 11, n.º 8 (17 de agosto de 2021): 1301. http://dx.doi.org/10.3390/met11081301.

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Vanadium as a rare element has a wide range of applications in iron and steel production, vanadium flow batteries, catalysts, etc. In 2018, the world’s total vanadium output calculated in the form of metal vanadium was 91,844 t. The raw materials for the production of vanadium products mainly include vanadium-titanium magnetite, vanadium slag, stone coal, petroleum coke, fly ash, and spent catalysts, etc. Chlorinated metallurgy has a wide range of applications in the treatment of ore, slag, solid wastes, etc. Chlorinating agent plays an important role in chlorination metallurgy, which is divided into solid (NaCl, KCl, CaCl2, AlCl3, FeCl2, FeCl3, MgCl2, NH4Cl, NaClO, and NaClO3) and gas (Cl2, HCl, and CCl4). The chlorination of vanadium oxides (V2O3 and V2O5) by different chlorinating agents was investigated from the thermodynamics. Meanwhile, this paper summarizes the research progress of chlorination in the treatment of vanadium-containing materials. This paper has important reference significance for further adopting the chlorination method to treat vanadium-containing raw materials.

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Guthrie, J. Peter, e John Cossar. "The chlorination of isobutyrophenone: determination of its pKa value and of the course of the reaction". Canadian Journal of Chemistry 68, n.º 3 (1 de março de 1990): 397–403. http://dx.doi.org/10.1139/v90-061.

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Chlorination of isobutyrophenone in alkaline aqueous solution leads to formation of α-hydroxyisobutyrophenone as the first detectable intermediate; a slow subsequent oxidation gives benzoate. From the rates of the initial chlorinations we have been able to determine the pKa value for the ketone as 18.18 ± 0.50. α-Chloroisobutyrophenone undergoes surprisingly rapid alkaline hydrolysis, kOH = 71.9 ± 1.5 M−1 s−1. Keywords: isobutyrophenone, chlorination, enolization, pKa, hydrolysis.

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Geremew, Abraham, Bezatu Mengistie, Esayas Alemayehu, Daniele Susan Lantagne, Jonathan Mellor e Geremew Sahilu. "Point-of-use water chlorination among urban and rural households with under-five-year children: a comparative study in Kersa Health and Demographic Surveillance Site, Eastern Ethiopia". Journal of Water, Sanitation and Hygiene for Development 8, n.º 3 (11 de maio de 2018): 468–80. http://dx.doi.org/10.2166/washdev.2018.173.

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Abstract Point-of-use water chlorination is one of the most effective means to prevent diarrhea in under-five children although challenges remain in its adoption and effective use. In Ethiopia, evidence of point-of-use water chlorination among households with under-five children in rural and urban settings that is verified with water testing is scarce. A comparative cross-sectional study was conducted among urban and rural households with under-five child in Kersa Health and Demographic Surveillance Site, Eastern Ethiopia from June to August, 2016. Data were collected from a caregiver of systematically selected households and analyzed using multivariable logistic regression. A total of 1,912 households were included in the analysis with a 96.5% response rate. In rural areas, 4.6% of caregivers were reportedly chlorinating water at point-of-use and 1.2% were confirmed with free residual chlorine. In urban areas, 17.1% of caregivers were reportedly chlorinating water and 6.6% were confirmed to have free residual chlorine. In two settings, caregivers' point-of-use water chlorination was associated with chlorine taste and water quality perception. Inaccessibility to treatment products in rural areas and use of bottled water in urban areas were among the reasons to discontinue point-of-use water chlorination. Behavior changing interventions with proper distribution and marketing is needed for sustainable point-of-use chlorination.

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Han, Peiwei, Jingmin Yan, Lunliang Zhang, Zhengchen Li e Shufeng Ye. "High-Temperature Chlorination of Nickel Oxide Using Calcium Chloride". Materials 16, n.º 21 (27 de outubro de 2023): 6888. http://dx.doi.org/10.3390/ma16216888.

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Attempts have been made to extract nickel from ores and nickel-containing wastes using the chlorination method. However, the use of gaseous chlorinating agents is limited due to their toxicity. High-temperature chlorination of nickel oxide using calcium chloride is analyzed in this study. The volatilization percentage is positively correlated to temperature and CaCl2 dosage and negatively correlated to oxygen partial pressure. The apparent activation energy is calculated to be 142.91 kJ/mol, between 1173 K and 1323 K, which suggests that the high-temperature chlorination of nickel oxide using calcium chloride is controlled by a chemical reaction.

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Drabik, G., e J. W. Naskalski. "Chlorination of N-acetyltyrosine with HOCl, chloramines, and myeloperoxidase-hydrogen peroxide-chloride system." Acta Biochimica Polonica 48, n.º 1 (31 de março de 2001): 271–75. http://dx.doi.org/10.18388/abp.2001_5135.

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N-acetyl-L-tyrosine (N-acTyr), with the alpha amine residue blocked by acetylation, can mimic the reactivity of exposed tyrosyl residues incorporated into polypeptides. In this study chlorination of N-acTyr residue at positions 3 and 5 in reactions with NaOCl, chloramines and the myeloperoxidase (MPO)-H2O2-Cl- chlorinating system were invesigated. The reaction of N-acTyr with HOCl/OCl- depends on the reactant concentration ratio employed. At the OCl-/N-acTyr (molar) ratio 1:4 and pH 5.0 the chlorination reaction yield is about 96% and 3-chlorotyrosine is the predominant reaction product. At the OCl-/N-acTyr molar ratio 1:1.1 both 3-chlorotyrosine and 3,5-dichlorotyrosine are formed. The yield of tyrosine chlorination depends also on pH, amounting to 100% at pH 5.5, 91% at pH 4.5 and 66% at pH 3.0. Replacing HOCl/OCl- by leucine/chloramine or alanine/chloramine in the reaction system, at pH 4.5 and 7.4, produces trace amount of 3-chlorotyrosine with the reaction yield of about 2% only. Employing the MPO-H2O2-Cl- chlorinating system at pH 5.4, production of a small amount of N-acTyr 3-chloroderivative was observed, but the reaction yield was low due to the rapid inactivation of MPO in the reaction system. The study results indicate that direct chlorination of tyrosyl residues which are not incorporated into the polypeptide structure occurs with excess HOCl/OCl- in acidic media. Due to the inability of the myeloperoxidase-H2O2-Cl- system to produce high enough HOCl concentrations, the MPO-mediated tyrosyl residue chlorination is not effective. Semistable amino-acid chloramines also appeared not effective as chlorine donors in direct tyrosyl chlorination.

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Zhang, Qian, Fan Yang e Yangjie Wu. "DDQ: the chlorinating reagent and oxidant for the ligand-directed ortho-chlorination of 2-arylpyridines". Org. Chem. Front. 1, n.º 6 (2014): 694–97. http://dx.doi.org/10.1039/c4qo00076e.

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Zhu, Yanshuo, e Wei Yu. "Photoinduced C(sp³)–H chlorination of amides with tetrabutyl ammonium chloride". Organic & Biomolecular Chemistry 19, n.º 46 (2021): 10228–32. http://dx.doi.org/10.1039/d1ob02081a.

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Tabolin, Andrey A., Anastasia A. Fadeeva e Sema L. Ioffe. "Chlorination of Conjugated Nitroalkenes with PhICl2 and SO2Cl2 for the Synthesis of α-Chloronitroalkenes". Synthesis 52, n.º 18 (14 de maio de 2020): 2679–88. http://dx.doi.org/10.1055/s-0040-1707396.

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Chlorination of conjugated nitroalkenes with iodobenzene dichloride or sulfuryl chloride to give target α-chloronitroalkenes in good yields is described. Details of the procedure depend on the donating ability of the nitroalkene substituents. The activity of the described chlorinating agents increases in order ‘PhICl2/Py’ < ‘SO2Cl2’ < ‘SO2Cl2/HCl’ with the former producing the best yields for highly donating substrates and the latter for non-activated groups. An autocatalytic role of hydrogen chloride and the chemoselectivity of chlorination were also demonstrated.

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Kumorkiewicz-Jamro, Agnieszka, Karolina Starzak, Katarzyna Sutor, Boris Nemzer, Zbigniew Pietrzkowski, Łukasz Popenda e Sławomir Wybraniec. "Structural Study on Hypochlorous Acid-Mediated Chlorination of Betanin and Its Decarboxylated Derivatives from an Anti-Inflammatory Beta vulgaris L. Extract". Molecules 25, n.º 2 (16 de janeiro de 2020): 378. http://dx.doi.org/10.3390/molecules25020378.

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Hypochlorous acid (HOCl) produced by neutrophils is a part of the natural innate immune response system in the human body, but excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. In this contribution, chlorination mechanism and position of the electrophilic substitution in betacyanins was studied by high-resolution mass spectrometry and further structural analyses by NMR techniques, which completed the identification of the chlorinated betacyanins. For the study on the influence of the position of decarboxylation on the chlorination mechanism, a comparison of the chlorination position between betanin as well as 17-, and 2,17-decarboxylated betanins was performed. The structural study confirmed that the chlorination position in betanin occurs within the dihydropyridinic moiety at carbon C-18. Therefore, out of the aqueous free chlorine equilibrium species: HOCl, OCl−, Cl2, and Cl2O, the most potent chlorinating agents are HOCl and Cl2O postulated previously and the attack of the Cl⁺ ion on the carbon C-18 with a cyclic intermediate version is considered.

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Xu, Changming, Zhaobin Zhu, Yongchang Wang e Li Zhao. "Copper(II)-Promoted Mono-Selective ortho C–H Chlorination of Arenes by Using Trimethyl(trichloromethyl)silane". Synlett 29, n.º 08 (15 de fevereiro de 2018): 1122–24. http://dx.doi.org/10.1055/s-0036-1591542.

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The first example of a Cu-promoted ortho-chlorination of aryl C–H bonds by using TMSCCl3 as chlorinating agent is reported. This reaction features a high selectivity toward monochlorination over dichlorination, compatibility with a variety of functional groups, and gram-scale synthesis.

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Gordon, JLM, MP Hartshorn, RJ Martyn, AJ Morgan, WT Robinson e GJ Wright. "The Chlorination of Some Substituted 2,4-Dimethylphenols". Australian Journal of Chemistry 47, n.º 2 (1994): 289. http://dx.doi.org/10.1071/ch9940289.

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Chlorination reactions of 2-chloro-3,4,6-trimethylphenol (4), 2-chloro-4,6-dimethylphenol (5) and 3-chloro-2,4,6-trimethylphenol (6) are described. In acetic acid or acetic anhydride solution, chlorinations yield predominantly the corresponding 4-chlorocyclohexa-2,5-dienones (8), (17a) and (29), but in carbon tetrachloride containing pyridine products are formed which result from the modification of the 4-methyl group in each substrate. X-Ray crystal structure analyses are reported for compounds (7), (14), (28) and (31).

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Stamhuis, Eize J., Henk Maatman e Geert E. H. Joosten. "Reactions of alicyclic ketones in carbon tetrachloride. II. Kinetics of the chlorination of 2-chlorocyclopentanone and 2-chlorocyclohexanone, catalyzed by hydrogen chloride". Canadian Journal of Chemistry 64, n.º 9 (1 de setembro de 1986): 1690–96. http://dx.doi.org/10.1139/v86-278.

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The kinetics of the direct chlorination of 2-chlorocyclopentanone (2-mccp) and 2-chlorocyclohexanone (2-mcch) in carbon tetrachloride, catalyzed by hydrogen chloride, were studied. Reaction products are all the possible 2,2-, 2,5-, and 2,6-dichloro compounds. The ratios depend on the concentrations of the monochloro compound and hydrogen chloride. Surprisingly, even at conversions of the monochloro compound as low as 2%, 2,2,5-trichlorocyclopentanone and 2,2,6-trichlorocyclohexanone, respectively, are also formed. The chlorination reaction of both monochloro ketones shows zero order in chlorine. The order in hydrogen chloride is 1.3. The order in 2-mccp and 2-mcch varies somewhat with the concentration of the ketone and was found to be roughly 1.7. The variation in reaction order is explained by a partial self-association of the ketones. The ketones act as substrates as well as basic catalysts in the rate-determining α- or α′-carbon deprotonation. General base catalysis is clearly demonstrated by a strong increase in the rate of chlorination of 2-mccp upon addition of cyclopentanone (cp) to the reaction mixture, which agrees with the mechanism as presented in a previous paper. Kinetic equations derived from the reaction models for the "separate" and "mixed" ketone chlorinations accurately describe the observed rates of the chlorination of 2-mccp and 2-mcch in the concentration range of 0.04–1.0 M.

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Opitz, Andreas, Werner Sulger, Ewald Daltrozzo e Rainer Koch. "‘Green' Synthesis of 2-Substituted 6-Hydroxy-[3H]-pyrimidin-4-ones and 4,6-Dichloropyrimidines: Improved Strategies and Mechanistic Study". Australian Journal of Chemistry 68, n.º 5 (2015): 814. http://dx.doi.org/10.1071/ch14073.

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An improved route to 2-substituted 6-hydroxy-[3H]-pyrimidin-4-ones 4 and to 2-substituted 4,6-dichloropyrimidines 5 is reported. Without using highly toxic reactants, compounds 4 can be prepared conveniently in a one pot synthesis on a one mol scale with average yields up to 80 %. 4,6-Dichloropyrimidines 5, which are usually prepared in small quantities, are synthesized with average yields of 80 %, using up to 80 g of starting material. The mechanism of the chlorination of 4 is investigated computationally for the first time. The results suggest that the chlorination with phosphoryl chloride occurs in an alternating phosphorylation–chlorination manner (pathway 1) which is preferred over a sequence which starts with two phosphorylations. The investigated 4,6-dichloropyrimidines described herein form strong complexes with dichlorophosphoric acid but weak complexes with hydrochloric acid (generated during workup). These latter complexes explain the necessity of using aqueous sodium carbonate during the working up. In order to prevent possible formation of pyrimidinium salts between intermediates or the final dichloropyrimidines and unreacted hydroxypyrimidone, the latter could be deactivated with a strong acid such as dichlorophosphoric acid, thus allowing chlorination but prohibiting salt formation. Because of its general applicability to all nitrogen heterocycle chlorinations with phosphoryl chloride, the proposed route to dichloropyrimidines without solvent or side products, using less toxic reactants, is of general synthetic interest.

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14

Rigas, Fotis, e Danae Doulia. "Spectrophotometric determination of iron (III) catalyst in organic compound chlorinations". Technium Romanian Journal of Applied Sciences and Technology 3, n.º 8 (28 de setembro de 2021): 13–21. http://dx.doi.org/10.47577/technium.v3i8.4399.

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In the science or industrial practice of chemical processes, iron (III) is sometimes used as a catalyst in organic compound chlorinations due to its effectiveness and low cost. Thus, a fast and easy method of determination in the system is useful especially when metallic iron is used as a precursor which is readily converted into iron (III) chloride by the gaseous chlorine used in the chlorination reactor. In the latter case, the determination of the produced catalytically effective iron (III) is a prerequisite for controlling the kinetic progress of chlorination. In this work, a method for the spectrophotometric determination of iron (III) chloride in organic media after complexation with methyl ethyl ketone is investigated. The formation of a strong o-complex of iron (III) with methyl ethyl ketone allows direct determination of iron at 360 nm.Beer’s law is valid up to absorbance 2.42, where the iron (III) concentration is 20.7 mg·L-1, with molar absorptivity (e) equal to 6.532×103 L·mol-1·cm-1 and Sandell’s sensitivity 8.5×10-3 ug·cm- 2. Standing time for color development is of the order of a few seconds and stability of color measurements exceeds 12 months. The method may be used among other applications in organic compounds chlorinations catalyzed by iron. These systems are complicated due to the coexistence of various complexes. Nevertheless, the method proposed being simple, fast, and not depending on the composition of the chlorination mixture and the amount of methyl ethyl ketone added was found to be suitable.

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Jia, Jin, Yuan Yuan Zhu, Ya Fei Zhang, Ruo Yu Chen, Bao Lin Xing e Ai Guo Zhou. "Synthesis and Analysis of Carbide-Derived Carbon from TiC by Chlorination". Key Engineering Materials 602-603 (março de 2014): 463–66. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.463.

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Carbide-derived carbons (CDCs) are produced from carbides by removing non-carbon elements in the process of selective etching. In this paper, CDC was prepared from TiC by chlorination at the temperature range of 600~1100°C. In the chlorinating process, carbide-derived carbon with different microstructure was obtained by controlling the reaction temperature. The structures of CDC were revealed with X-ray diffraction and Raman spectroscopy. The morphologies of CDC were analyzed by scanning electron microscope. From X-ray diffraction analysis, the CDC obtained from TiC in this experiment mainly consisted of amorphous carbon. Basing on scanning electron microscopy, carbide-derived carbon from TiC maintained the shape and size of TiC particles. Keywords: Carbide-derived carbons; chlorination; TiC

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Vinayak, Botla, Pardhi Vishal Ravindrakumar, Daggupati V. Ramana e Malapaka Chandrasekharam. "Revisiting 1-chloro-1,2-benziodoxol-3-one: efficient ortho-chlorination of aryls under aqueous conditions". New Journal of Chemistry 42, n.º 11 (2018): 8953–59. http://dx.doi.org/10.1039/c8nj00530c.

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The ortho-selective amide directing group assisted chlorination of aryls with the easily accessible 1-chloro-1,2-benziodoxol-3-one as oxidant as well as chlorinating reagent is reported in the absence of a radical initiator. The open air, aqueous conditions and recyclable reagent demonstrate the green principles involved in the reaction.

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Tsitsifli, Stavroula, e Vasilis Kanakoudis. "Assessing the Impact of DMAs and the Use of Boosters on Chlorination in a Water Distribution Network in Greece". Water 13, n.º 16 (4 de agosto de 2021): 2141. http://dx.doi.org/10.3390/w13162141.

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Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.

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Kovach, Steve, Larry Curtis e Jim Allen. "CHLORINATION TO PREVENT CLOGGING IN MICRO-IRRIGATION SYSTEMS". HortScience 27, n.º 11 (novembro de 1992): 1174b—1174. http://dx.doi.org/10.21273/hortsci.27.11.1174b.

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Irrigating with a micro-irrigation (drip) system offers improved crop quality and yield with significant savings of energy and water. To deliver these benefits reliably, a grower's system must include chlorinations or some other effective water treatment program to prevent clogging, the most common problem of micro-irrigation. Step-by-step procedures of chlorination of micro-irrigation systems are discussed. Injected into micro-irrigation systems, chlorine kills the micro-organisms—bacteria, fungi and algae—that may be in a water source and are the most common system cloggers.

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Dössegger, Lukas, Alan Tournefier, Laura Germann, Nicola Gärtner, Timon Huonder, Cosmas Etenu, Kennedy Wanyama, Henry Ouma e Regula Meierhofer. "Assessment of low-cost, non-electrically powered chlorination devices for gravity-driven membrane water kiosks in eastern Uganda". Waterlines 40, n.º 2 (1 de abril de 2021): 92–106. http://dx.doi.org/10.3362/1756-3488.20-00014.

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Recontamination during transport and storage is a common challenge of water supply in low-income settings, especially if water is collected manually. Chlorination is a strategy to reduce recontamination. We assessed seven low-cost, non-electrically powered chlorination devices in gravity-driven membrane filtration (GDM) kiosks in eastern Uganda: one floater, two in-line dosers, three end-line dosers (tap-attached), and one manual dispenser. The evaluation criteria were dosing consistency, user-friendliness, ease of maintenance, local supply chain, and cost. Achieving an adequate chlorine dosage (∼2 mg/L at the tap and ≥ 0.2 mg/L after 24 h of storage in a container) was challenging. The T-chlorinator was the most promising option for GDM kiosks: it achieved correct dosage (CD, 1.5–2.5 mg/L) with a probability of 90 per cent, was easy to use and maintain, economical, and can be made from locally available materials. The other in-line option, the chlorine-dosing bucket (40 per cent CD) still needs design improvements. The end-line options AkvoTur (67 per cent CD) and AquatabsFlo® (57 per cent CD) are easy to install and operate at the tap, but can be easily damaged in the GDM set-up. The Venturi doser (52 per cent CD) did not perform satisfactorily with flow rates > 6 L/min. The chlorine dispenser (52 per cent CD) was robust and user-friendly, but can only be recommended if users comply with chlorinating the water themselves. Establishing a sustainable supply chain for chlorine products was challenging. Where solid chlorine tablets were locally rarely available, the costs of liquid chlorine options were high (27–162 per cent of the water price).

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Zhao, Tuan, Hong Tao Lin, Bao Wei Li e Da Qiang Cang. "Recovery of Niobium from Baogang Tailings by Carbochlorination". Advanced Materials Research 201-203 (fevereiro de 2011): 1691–98. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.1691.

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Carbochlorination of niobium in the tailings of Baogang concentrator was experimentally studied, and the activated carbon was used as the reducing agent and chlorine gas as the chlorinating agent. The effects of the reaction time and the temperature on chlorination rate of niobium in tailings were investigated. The result showed that when the tailings were chlorinated at 800 for 2 h,96.15% of niobium was yield.

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Xiao, Jing, e Li-Biao Han. "Atom-efficient chlorination of benzoic acids with PCl3 generating acyl chlorides". Journal of Chemical Research 43, n.º 5-6 (maio de 2019): 205–10. http://dx.doi.org/10.1177/1747519819861316.

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By using PCl3 as the chlorinating reagent, various carboxylic acids are converted into the corresponding acid chlorides in good yields. This method features high atom efficiency in which nearly all three chlorine atoms of PCl3 are used in the chlorination. Moreover, the work-up procedure is simple since the major side product is phosphonic acid [HP(O)(OH)2] which is non-toxic and easily removed by filtration. A possible mechanism is proposed in this paper.

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Wang, Xinye, Hao Xie, Rong Du, Yuying Liu, Pingfang Lin, Jubing Zhang, Changsheng Bu, Yaji Huang e Wen Zhang. "High-temperature chlorination of PbO and CdO induced by interaction with NaCl and Si/Al matrix". RSC Advances 8, n.º 60 (2018): 34449–58. http://dx.doi.org/10.1039/c8ra06255b.

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Yu, Tong, Shoufang Sun, Yunlong Zhao, Lingxue Wang, Ping Li, Zhuo Chen, Xuejun Bi e Xueqing Shi. "Effects of chlorine disinfection on RO membrane biofouling at low feed water temperature for wastewater reclamation". Journal of Water Reuse and Desalination 12, n.º 4 (24 de novembro de 2022): 438–50. http://dx.doi.org/10.2166/wrd.2022.156.

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Abstract Chlorine disinfection has been reported to be ineffective in controlling RO membrane biofouling in some projects. Feed water temperature is a crucial factor in the formation of RO membrane biofouling. It has a positive impact on the wide application of the RO process to ascertain whether chlorine disinfection can alleviate the membrane biofouling at low temperatures. In this study, the effects of chlorination on the RO membrane biofouling at low feed water temperature (10 °C) were investigated by a lab-scale RO apparatus. The final normalized flux was 0.33 and 0.29 with and without chlorination, respectively. According to the normalized flux decline curve, chlorination could not alleviate the RO membrane fouling at low temperature. Based on the intermediate blocking model, chlorination increased the membrane fouling potential of the feed water. At low temperature, the biofilm on the membrane with chlorination was thinner and denser than that without chlorination. In addition, the membrane with chlorination contained more foulants and dissolved organic matter than that without chlorination. Chlorination failed to continuously prevent bacteria accumulation on RO membrane at low temperature, but screened out bacteria that were potentially more suitable for the low-temperature membrane environment.

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Juárez-Ornelas, Kevin A., Manuel Solís-Hernández, Pedro Navarro-Santos, J. Oscar C. Jiménez-Halla e César R. Solorio-Alvarado. "Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study". Beilstein Journal of Organic Chemistry 20 (15 de julho de 2024): 1580–89. http://dx.doi.org/10.3762/bjoc.20.141.

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The reaction mechanism for the chlorination and bromination of 2-naphthol with PIDA or PIFA and AlX3 (X = Cl, Br), previously reported by our group, was elucidated via quantum chemical calculations using density functional theory. The chlorination mechanism using PIFA and AlCl3 demonstrated a better experimental and theoretical yield compared to using PIDA. Additionally, the lowest-energy chlorinating species was characterized by an equilibrium of Cl–I(Ph)–OTFA–AlCl3 and [Cl–I(Ph)][OTFA–AlCl3], rather than PhICl2 being the active species. On the other hand, bromination using PIDA and AlBr3 was more efficient, wherein the intermediate Br–I(Ph)–OAc–AlBr3 was formed as active brominating species. Similarly, PhIBr2 was higher in energy than our proposed species. The reaction mechanisms are described in detail in this work and were found to be in excellent agreement with the experimental yield. These initial results confirmed that our proposed mechanism was energetically favored and therefore more plausible compared to halogenation via PhIX2.

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Tang, Biao Wen, e Hua Lin. "Comparison of Chlorination and Ozonation Disinfection for Municipal Wastewater Reclamation". Advanced Materials Research 518-523 (maio de 2012): 1877–80. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.1877.

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For the microbial Safety of municipal reclaimed wastewater, comparison of chlorination and ozonation disinfection efficiency was investigated. Chlorination can not completely inactivate the E. coli, which reduce to 100 count/L and maintain stabilization with chlorination dose increasing to16mg/L, and different chlorination disinfectors have almost disinfect efficiently. As a strong disinfection, the same inactivation efficiency of E. coli as chlorination could be achieved an ozone dose of 7 mg/L, and its running cost is about 0.06 yuan/m3.

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Xiong, Xiaolu, Guangshi Li, Zhongya Pang, Sha Chen, Xingli Zou, Qian Xu, Hongwei Cheng, Shenggang Li, Kai Zhu e Xionggang Lu. "Experimental and computational approaches to study the chlorination mechanism of pentlandite with ammonium chloride". RSC Advances 12, n.º 30 (2022): 19232–39. http://dx.doi.org/10.1039/d2ra03488c.

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The chlorination mechanism of pentlandite with NH4Cl has been proposed. The chlorination of pentlandite can be achieved by two pathways, where O2 plays a crucial role in promoting the chlorination process.

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Zhao, Xinxin, Yan Liu, Long Wang, Yutong Hua, Tianhao Cheng, Tingan Zhang e Qiuyue Zhao. "Co-Extraction of Aluminum and Silicon and Kinetics Analysis in Carbochlorination Process of Low-Grade Bauxite". Materials 17, n.º 14 (22 de julho de 2024): 3613. http://dx.doi.org/10.3390/ma17143613.

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Addressing the issue that the Bayer process is not suitable for low-grade bauxite, carbochlorination was proposed to recover aluminum and silicon from low-grade bauxite. This study focused on the behavior of aluminum and silicon during the carbochlorination process of low-grade bauxite. The impact of various process parameters on the chlorination efficiency was investigated, and the chlorination mechanism and kinetics of aluminum and silicon chlorination in bauxite were analyzed and discussed. Under optimal experimental conditions, the chlorination efficiency of Al2O3 and SiO2 reached 94.93% and 86.32%, respectively. The carbochlorination of aluminum and silicon in bauxite adhered to a shrinking, unreacted core model governed by gas diffusion within the product layer. This process can be bifurcated into two stages. Additionally, calculations were conducted to determine the apparent activation energy and reaction order of the chlorination processes involving Al2O3 and SiO2. Examining the chlorination mechanism revealed that the bauxite carbochlorination encompasses transformations among various minerals. Notably, the aluminum component prefers to participate in the carbothermal chlorination reaction over silicon.

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Abdullah, Norazharuddin Shah, Azizan Aziz e Hussin Kamarudin. "Ilmenite Chlorination: Usage of Gaseous Carbon Tetrachloride at Relatively Lower Temperatures". Advanced Materials Research 1087 (fevereiro de 2015): 389–93. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.389.

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Malaysian ilmenite from “amang” or tin mining waste is well known for its physical and chemical complexity, making it difficult to be treated conventionally. With knowledge of ilmenite is rich in titania and iron, extractive efforts were made in order to segregate and recover the components of ilmenite, with major interest being the removal and retrieval of titanium. In this study, the extent of chlorination execution is observed by means of weight loss studies under various parameters, with an aim of successful chlorination at lower temperatures. At 723 K, chlorination trials were done using gaseous hydrogen chloride (gHCl), carbon monoxide-chlorine gas mixtures (gCO-Cl) and gaseous carbon tetrachloride (gCT). It was clearly seen that at such a relatively low temperature, only gCT was able to obtain a good chlorination degree, with up to 90% chlorination of –45+37 μm ilmenite particles were observed after 1 hour of reaction. With similar size fraction and time, hydrogen chloride was only able to give approximately 6% of chlorination while the mixture of carbon monoxide and chlorine was seen incapable of giving anything higher than a 6% reaction. Initial observation suggests that the chlorination of ilmenite by carbon tetrachloride physically resembles the core shrinking model, although proper kinetic studies needs to be done to confirm this. Changes in various parameter values are seen to be quite sensitive to the overall ilmenite chlorination (via gCT) process. This study have shown that gCT presents an interesting route for the chlorination of complex ores such as ilmenite.

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Guthrie, J. Peter, e John Cossar. "The chlorination of acetone: a complete kinetic analysis". Canadian Journal of Chemistry 64, n.º 6 (1 de junho de 1986): 1250–66. http://dx.doi.org/10.1139/v86-208.

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Rate constants are reported for all of the major steps followed in the chlorination of acetone, including the chlorination of mono- and 1,1-dichloroacetone, the chlorination of hydroxyacetone, the chlorination and hydroxide-catalyzed rearrangement of 1,1-dihydroxyacetone, and the haloform cleavage of trichloroacetone. pKa values are reported for hydroxyacetone and monochloroacetone. Rate constants for the hydrolyses of chloroacetone and 1,1-dichloroacetone are reported; these reactions are probably not SN2 displacements but proceed by addition of hydroxide and intramolecular displacement.

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Kurihara, Masaru, Hiromu Takeuchi e Yohito Ito. "A Reliable Seawater Desalination System Based on Membrane Technology and Biotechnology Considering Reduction of the Environmental Impact". Environments 5, n.º 12 (3 de dezembro de 2018): 127. http://dx.doi.org/10.3390/environments5120127.

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The application of seawater desalination technology using a reverse osmosis (RO) membrane has been expanding because it requires less energy compared with other distillation methods. Even in Middle Eastern countries where energy costs are lower such as Saudi Arabia, UAE, Qatar, and Kuwait, almost all desalination plants where only water production is required have adopted the RO method. However, large plants in excess of half mega-ton size are required, and Seawater Reverse Osmosis (SWRO) operation lacks reliability due to heavy biofouling and large amounts of briny discharge contaminated with chemicals. For reliable desalination systems with lower environmental impact, membrane-processing technology, including biotechnology (such as marine bacteria), has been examined as national research in Japan in the “Mega-ton Water System” project. We examined the influence of chlorination on marine bacteria using the fluorescence microscopic observation method and found that the effect of chlorination is limited. Chlorination sterilization triggers biofouling and sodium bisulfate (SBS) addition as a de-chlorinating agent also triggers biofouling, so a process with no chlorine or SBS addition would reduce biofouling. As polyamide SWRO membranes have low chlorine resistivity, such a process would enable longer membrane life in real plants. We used a biofouling monitoring technology, the Membrane Biofilm Formation Rate (mBFR), to design a process that involves no chlorine or SBS addition and verified it in the Arabian Gulf Sea, of Saudi Arabia, which is one of the most difficult and challenging seawaters in which to control biofouling. Furthermore, by minimizing the addition of a sterilizer, the desalination system became more environmentally friendly.

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Zhang, Ai, Xinyuan Jiang, Qiancheng Wang, Siyu Hao, Dahai Zhu, Jie Wang, Ce Wang e Mingyan Liu. "Assessment of Glucocorticoid Removal by UVA/Chlorination and Ozonation: Performance Comparison in Kinetics, Degradation Pathway, and Toxicity". Water 14, n.º 16 (13 de agosto de 2022): 2493. http://dx.doi.org/10.3390/w14162493.

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Glucocorticoids (GCs) have drawn great concern due to widespread contamination in the environment and application in treating COVID-19. This work aimed to compare the performance of UVA/chlorination and ozonation on GC removal in terms of removal efficiency, degradation pathway, and toxicity change, with fluocinolone acetonide (FA), triamcinolone acetonide (TA), and clobetasol propionate (CP) as target compounds. The results showed that both UVA/chlorination and ozonation could degrade GCs. Compared with UVA/chlorination (removal efficiency of 89% for FA, 86% for TA, and 90% for CP at 7 h), ozonation (removal efficiency of 90% for FA, 96% for TA, and 98% for CP at 15 min) was more effective in GC removal. Photodegradation contributed most to GC removal during UVA/chlorination, while O3 molecules were the main functional species during ozonation. H-abstraction, dechlorination, carbon–carbon bond cleavage, and ester hydrolysis were proposed for both UVA/chlorination and ozonation based on the identification of intermediates. However, ozone tended to attack C=C double bonds, resulting in the cracked benzene ring of GCs, while chlorine was more likely to attack alcohol and ketone groups. Although most GCs were removed during ozonation and UVA/chlorination, their acute toxicities slightly declined. Compared with UVA/chlorination, ozonation was more effective in toxicity reduction.

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Liu, Jian, Shu Ming Wen, Qi Cheng Feng, Yu Chen, Shao Jun Bai, Dan Liu e Dan Dan Wu. "Response Surface Design for Remove of Copper from a Fe-Rich Pyrite Cinder". Advanced Materials Research 622-623 (dezembro de 2012): 508–12. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.508.

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The study aims to remove copper from a pyrite cinders using chlorination roasting and optimizing the roasting parameters through response surface methodology (RSM). After a series of experiments, a quadratic model was suggested by RSM to correlate the variables to the copper volatilization ratio. The results indicate that the model is in good agreement with the experimental data and the dosage of chlorinating agent and roasting temperature play a key role in improving the volatilization ratio. The optimum conditions for remove copper from the cinders were identified as chlorinating agent dosage at 5%, roasting temperature at 1155.05 °C and roasting time of 10 minutes; under such a condition, an average copper volatilization ratio of 95.16% was achieved from the cinder.

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Hichem, Hadjeres, M. Pradhanang Soni, Boving Thomas, Meadows Maxwell e Benzerrouk Souheil. "The Case for LED-UVC as a Primary Disinfectant for Small Sustainable Drinking Water Systems". MATEC Web of Conferences 280 (2019): 05014. http://dx.doi.org/10.1051/matecconf/201928005014.

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High loads of natural organic matter (NOM) in source water increase levels of toxic byproducts during disinfection, including trihalomethanes (THMs) which are formed when NOM is chlorinated. This study explores the efficacy of using UVC-LED as a primary disinfectant, with lower concentrations of chlorine used as a secondary disinfectant. Both treatment trains with conventional chlorination and UV irradiation with low chlorination reduced total coliforms and E. Coli counts to less than 1 Cfu/100 ml. UV with low chlorination produced approximately 4.6 times less THMs compared to conventional chlorination.

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Flid, M. R. "Oxidative chlorination of hydrocarbons. Part 2. Oxidative chlorination of propylene, 1,3-butadiene, acetylene and benzene". Kataliz v promyshlennosti 24, n.º 2 (20 de março de 2024): 15–25. http://dx.doi.org/10.18412/1816-0387-2024-2-15-25.

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The review paper considers main regularities of the oxidative chlorination of some unsaturated hydrocarbons: propylene, acetylene, butadiene-1,3 and benzene. It was shown that the implementation of such processes in the gas phase requires the presence of heterogeneous catalysts based on copper or palladium in the system. Depending on the process conditions, the products of additive or substitutive chlorination are formed. Kinetic equations and probable conversion mechanisms were proposed for the oxidative chlorination of propylene, acetylene and benzene. Prospects of the practical implementation of the oxidative chlorination of some unsaturated hydrocarbons were considered.

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Morris, R. D., A. M. Audet, I. F. Angelillo, T. C. Chalmers e F. Mosteller. "Chlorination, chlorination by-products, and cancer: a meta-analysis." American Journal of Public Health 82, n.º 7 (julho de 1992): 955–63. http://dx.doi.org/10.2105/ajph.82.7.955.

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Parisotto, Stefano, Emanuele Azzi, Alberto Lanfranco, Polyssena Renzi e Annamaria Deagostino. "Recent Progresses in the Preparation of Chlorinated Molecules: Electrocatalysis and Photoredox Catalysis in the Spotlight". Reactions 3, n.º 2 (3 de abril de 2022): 233–53. http://dx.doi.org/10.3390/reactions3020018.

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Among halogenated molecules, those containing chlorine atoms are fundamental in many areas such as pharmaceuticals, polymers, agrochemicals and natural metabolites. Despite the fact that many reactions have been developed to install chlorine on organic molecules, most of them rely on toxic and hazardous chlorinating reagents as well as harsh conditions. In an attempt to move towards more sustainable approaches, photoredox catalysis and electrocatalysis have emerged as powerful alternatives to traditional methods. In this review, we collect the most recent and significant examples of visible-light- or current-mediated chlorination published in the last five years.

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Zholdasbay, E. E., A. A. Argyn, M. B. Kurmanseitov, K. S. Dosmukhamedova e G. S. Daruesh. "Study of the influence of temperature and duration of chlorinating roasting on the extraction of gold from E-waste". Kompleksnoe Ispolzovanie Mineralnogo Syra = Complex Use of Mineral Resources 333, n.º 2 (9 de julho de 2024): 51–58. http://dx.doi.org/10.31643/2025/6445.17.

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In this work, based on experimental studies, the effect of roasting temperature and duration on the chlorination of gold from E-waste under low-temperature conditions was studied. It has been established that in the low-temperature range of 150-300 °C, the gold content in the residue shows a sharp decrease, reaching its minimum of 8 ppm at 250 °C. A further increase in temperature does not affect the gold content in the cinder. It has been shown that during chlorinating roasting above a temperature of 250 °C, side reactions should be expected to occur with the formation of additional phases representing chlorides of copper, iron and other elements. The results of SEM and XRD analyzes of the solid phase obtained after chlorinating roasting at a temperature of 250 °C and a roasting duration of 20 minutes showed the presence of copper and iron chlorides in them. Optimal technological parameters and modes of the process of chlorinating roasting of E-waste with gaseous chlorine have been established: temperature – 250 °С; roasting duration – 20 minutes; chlorine consumption is 1.5 times more than the stoichiometrically required amount (SRA) for gold chlorination. Under optimal roasting conditions, a high, up to ~97.6%, recovery of gold in the form of gold chloride (AuCl3) was achieved. The results of the experiments can be a basic basis and make it possible to conduct more representative experiments (scaling) in the future, taking into account the established optimal technological parameters. This will provide a chance to evaluate the possibility of extracting gold from E-waste of different types and compositions and to conduct further research on obtaining pure gold from the collected representative amount of gold sublimate AuCl3 by smelting.

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Gao, Chao, Hongchen Li, Miaochang Liu, Jinchang Ding, Xiaobo Huang, Huayue Wu, Wenxia Gao e Ge Wu. "Regioselective C–H chlorination: towards the sequential difunctionalization of phenol derivatives and late-stage chlorination of bioactive compounds". RSC Adv. 7, n.º 74 (2017): 46636–43. http://dx.doi.org/10.1039/c7ra09939h.

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Guthrie, J. Peter, e John Cossar. "The chlorination of propiophenone; determination of pKa value and of the course of the reaction". Canadian Journal of Chemistry 68, n.º 11 (1 de novembro de 1990): 2060–69. http://dx.doi.org/10.1139/v90-315.

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Chlorination of propiophenone in alkaline aqueous solution leads to formation of α-hydroxypropiophenone as the first detectable intermediate; this undergoes slower oxidation to aromatic acids without any accumulation of further intermediates. From the rates of the initial chlorination we have been able to determine the pKa value as 17.56 ± 0.51. Keywords: propiophenone, chlorination, hydrolysis, rearrangement, pKa.

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Rodriguez, Manuel J., e Jean-B. Sérodes. "Neural network-based modelling of the adequate chlorine dosage for drinking water disinfection". Canadian Journal of Civil Engineering 23, n.º 3 (1 de junho de 1996): 621–31. http://dx.doi.org/10.1139/l96-871.

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A neural network modelling approach has been developed to estimate the disinfectant dose adjustments required during water re-chlorination in storage tanks. The approach is based on representative operational and water quality historical data which intrinsically characterize the operators' use of know-how in their routine tasks. The development of the model requires the elimination of the historical cases in which re-chlorination results were inadequate. The results obtained for the model demonstrate that neural networks are capable of satisfactorily identifying the knowledge patterns contained in data with regard to the re-chlorination process for both winter and summer conditions. The practical use of such a model may assist operators in adjusting re-chlorination doses and may favour chlorine economization and the improvement of the water quality in the distribution system. Key words: drinking water, neural networks, distribution systems, chlorination, modelling, water quality.

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Du, Junyan, Yiyu Xiao, Shiyuan Liu, Lijun Wang e Kuo-Chih Chou. "Mechanism of Selective Chlorination of Fe from Fe2SiO4 and FeV2O4 Based on Density Functional Theory". Metals 13, n.º 1 (10 de janeiro de 2023): 139. http://dx.doi.org/10.3390/met13010139.

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Vanadium slag is an important resource containing valuable elements such as Fe, V, Ti, and so on. A novel selective chlorination method for extracting these valuable elements from vanadium slag has been proposed recently. The proposed methods could recover valuable elements with a high recovery ratio and less of an environmental burden, while the study on the chlorination mechanism at the atom level was still insufficient. Fe2SiO4 and FeV2O4 are the two main phases of vanadium slag, and the iron element can be selectively extracted via the chlorination of NH4Cl. The NH4Cl decomposes into NH3 gas and HCl gas, which was the true chlorination agent. As a result, the chlorination reactions of Fe2SiO4 and FeV2O4 with HCl were firstly calculated using FactSage 8.0. Then, this paper studied the characteristics of HCl adsorption on the Fe2SiO4(010) surface and the FeV2O4(001) Fe-terminated surface mechanism of the selective chlorination of Fe from Fe2SiO4 and FeV2O4 via DFT calculations. The processes of chlorination of Fe2SiO4 and FeV2O4 involved the processes of removing O atoms from them with HCl gas. The iron in Fe2SiO4 was selectively chlorinated because HCl could adsorb on the iron site but could not adsorb on the silicon site. The iron in FeV2O4 was selectively chlorinated because the electronegativity gap between V and O was more significant than that between the Fe and O elements.

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Kajigaeshi, Shoji, Takaaki Kakinami†, Masayuki Moriwaki, Toshio Tanaka e Shizuo Fujisaki. "An effective chlorinating agent benzyltrimethylammonium tetrachloroiodate, benzylic chlorination of alkylaromatic compounds". Tetrahedron Letters 29, n.º 45 (janeiro de 1988): 5783–86. http://dx.doi.org/10.1016/s0040-4039(00)82191-7.

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Wang, Hong, Dong Yuan Jin, Zhi Qiang Yang, Yong Hong Gao, Jian Wei Tao e Li Hua Li. "Synthesis of Phenoxy Amide Derivatives". Advanced Materials Research 396-398 (novembro de 2011): 2318–21. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.2318.

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Several kinds of new derivatives of N-substituted-4-(p-chlorophenoxy)acetamide and N-substituted-2,4-dichlorophenoxy acetamide were synthesized with methyl chloroacetate. The influence of solvent on the chlorination occurred in the benzene ring of phenoxy acetamide additives has been investigated by using sulfonyl chloride as chlorination agent. Result shows that the higher polarity of solvent is beneficial to the chlorination.

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AL-ARYDAH, MO'TASSEM, ABUBAKAR MWASA, JEAN M. TCHUENCHE e ROBERT J. SMITH? "MODELING CHOLERA DISEASE WITH EDUCATION AND CHLORINATION". Journal of Biological Systems 21, n.º 04 (dezembro de 2013): 1340007. http://dx.doi.org/10.1142/s021833901340007x.

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Cholera, characterized by severe diarrhea and rapid dehydration, is a water-borne infectious disease caused by the bacterium Vibrio cholerae. Haiti offers the most recent example of the tragedy that can befall a country and its people when cholera strikes. While cholera has been a recognized disease for two centuries, there is no strategy for its effective control. We formulate and analyze a mathematical model that includes two essential and affordable control measures: water chlorination and education. We calculate the basic reproduction number and determine the global stability of the disease-free equilibrium for the model without chlorination. We use Latin Hypercube Sampling to demonstrate that the model is most sensitive to education. We also derive the minimal effective chlorination period required to control the disease for both fixed and variable chlorination. Numerical simulations suggest that education is more effective than chlorination in decreasing bacteria and the number of cholera cases.

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Yang, Weiqing, Yongjing Cao, Hongrui Cheng, Qingrong Sun e Menglin Ma. "The Study on Chlorination by Sulfuryl Chloride of Benzene/Pyridine Carboxamides and Carbonitriles". Letters in Organic Chemistry 17, n.º 10 (17 de novembro de 2020): 788–94. http://dx.doi.org/10.2174/1570178617666191203101254.

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In the chlorination of N-[2-aryl-1-(1-piperidinylcarbonyl)ethenyl]arenecarboxamides, it has been found that a derivative having two methoxy substituents on the arenecarbonyl ring undergoes chlorination on the same ring rather than converting into the expected enamine bond chlorination product. Based on the above results, the chlorination of benzamides/nicotinamides by sulfuryl chloride (SO2Cl2) has been studied. We developed a method of synthesizing aromatic chlorinated compounds by treating aromatic amides or nitriles with SO2Cl2 in dichloromethane at 0oC without catalyst. This is a new mild method and gives good yields, especially when benzene ring is substituted by amide or cyano group together with the alkoxy group.

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Dai, Ji, Feng Jiang, Chii Shang, Kwok-ming Chau, Yuet-kar Tse, Chi-fai Lee, Guang-Hao Chen, Jingyun Fang e Liming Zhai. "The impact of chlorine disinfection on biochemical oxygen demand levels in chemically enhanced primary treatment effluent". Water Science and Technology 68, n.º 2 (1 de julho de 2013): 380–86. http://dx.doi.org/10.2166/wst.2013.257.

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The response trends of biochemical oxygen demand (BOD) and organic strength after the chlorination/dechlorination process were explored through a 2-year, 5-month chemically enhanced primary treatment (CEPT) effluent onsite monitoring program and a 2-month laboratory-scale study. The monitoring results showed that better instantaneous mixing at the chlorine injection point reduced the effect of chlorination/dechlorination on the 5-day BOD levels. The laboratory study results demonstrated that chlorination did not change the particle size distribution, dissolved organic carbon, or chemical oxygen demand of the organic content of the effluent. Nevertheless, chlorination/dechlorination strongly affected the BOD measurement when nitrification was inhibited by changing bioactivity/biodegradation rates.

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Hubbard, Abigail, Takao Okazaki e Kenneth K. Laali. "Chlorination of Aromatics with Trichloroisocyanuric Acid (TCICA) in Brønsted-Acidic Imidazolium Ionic Liquid [BMIM(SO3H)][OTf]: an Economical, Green Protocol for the Synthesis of Chloroarenes". Australian Journal of Chemistry 60, n.º 12 (2007): 923. http://dx.doi.org/10.1071/ch07261.

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A survey study on electrophilic chlorination of aromatics with trichloroisocyanuric acid (TCICA) in Brønsted-acidic imidazolium ionic liquid [BMIM(SO3H)][OTf] is reported. The reactions are performed under very mild conditions (at ~50°C) and give good to excellent yields, depending on the substrates. Chemoselectivity for mono- v. dichlorination can be tuned by changing the arene-to-TCICA ratio and the reaction time. The survey study and competitive experiments suggest that triprotonated/protosolvated TCICA is a selective/moderately reactive transfer-chlorination electrophile. Density functional theory was used as guide to obtain further insight into the nature of the chlorination electrophile and the transfer-chlorination step.

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Ilic, Ilija, Katarina Cerovic, Srecko Stopic e Zeljko Kamberovic. "Chlorination of nickel ore by gaseous chlorine in the presence of active additives". Journal of Mining and Metallurgy, Section B: Metallurgy 39, n.º 3-4 (2003): 427–41. http://dx.doi.org/10.2298/jmmb0304427i.

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Paper presents a thermodynamic analysis of chemical reactions occurring during chlorination with and without additives for both nickel oxides and nickel ferrites, which are component parts of nickel ore. The experimental research investigated the influence of temperature in the range from 600 up to 1000 ?C and time (up to 3 h) on the chlorination degree of nickel ores with and without additives. It was found that the introduction of additives such as C, S, BaS and NaCl intensified the chlorination of nickel ore. The results can be applied and may help determine the optimal conditions for the chlorination of low-grade ferrous nickel ores.

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Jia, Jin, Aiguo Zhou, Yuanyuan Zhu, Jiang Liu, Shihao Feng, Yufan Tao, Baoling Xing e Chuanxiang Zhang. "Preparation and Microstructure Analysis of TiC-Derived Carbons with Hierarchical Pore Structure". Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/163415.

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Carbide-derived carbons (CDCs) with hierarchical pore structure are prepared from commercial TiC powders by chlorination at temperature range of 600–1100°C. As-synthesized CDCs mainly consist of amorphous carbon and there exists a graphitization trend at chlorinating temperature above 800°C. If chlorinating temperature is below 1000°C, CDC particles maintain the shape of original TiC particles. Above 1000°C, obvious cracks appear in CDC particles and some particles are broken into small parts. The specific surface area (SSA) of CDCs is in the range from 672 m2/g to 1609 m2/g. The highest SSA is 1609 m2/g for CDC chlorinated at 1000°C. Most pores in these CDCs are micropores with the size of 0.7–2 nm. However, some mesopores and macropores also exist.

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Lykasov, Aleksander A., Grigoriy M. Ryss e Dmitrij A. Ponomarev. "Removal of Copper from the Sulphide Copper Smelting Waste Slag". Materials Science Forum 989 (maio de 2020): 388–93. http://dx.doi.org/10.4028/www.scientific.net/msf.989.388.

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The applicability of chloridizing roasting for removal of copper from the sulphide copper smelting waste slag of the ”Karabashmed'” copper-smelting plant is investigated. Calcium chloride CaCl2 was used as chlorination agent. It is established that the chlorinating roasting of the initial slag presented by fayalite 2FeO∙SiO2, hasn't led to noticeable removal of copper. Considerable degree of removal of copper (more than 90 %) has been reached as a result of the chlorinating of preliminary oxidized slag in which fayalite was oxidized to form Fe2O3 and SiO2. Using a fractional factorial experiment 23–1, dependence of degree of copper removal from preliminary oxidized slag upon temperature of the chlorinating roasting, time of isothermal roasting period and content of CaCl2 was established. It is found that increase of temperature and of CaCl2 content leads to increase in degree of copper removal. The influence of time of isothermal roasting period in the studied interval (2–4 h) is statistically insignificant.

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