Aluminium chloride induced isomerisation of 1,1,2-trichlorotrifluoroethane and 1,2-difluorotetrachloroethane

Oldřich Paleta; František Liška; Antonín Pošta; Václav Dědek

doi:10.1135/cccc19800104

Aluminium chloride induced isomerisation of 1,1,2-trichlorotrifluoroethane and 1,2-difluorotetrachloroethane

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800104 ◽

1980 ◽

Vol 45 (1) ◽

pp. 104-114 ◽

Cited By ~ 5

Author(s):

Oldřich Paleta ◽

František Liška ◽

Antonín Pošta ◽

Václav Dědek

Keyword(s):

Correlation Diagram ◽

Aluminium Chloride ◽

Bond Energies ◽

Preparative Yield ◽

Physico Chemical

Under comparable conditions, the isomerisation of 1,1,2-trichlorotrifluoroethane (I) to 1,1,1-trichlorotrifluoroethane (II) is more difficult than the isomerisation of 1,2-difluorotetrachloroethane (III) to 1,1-difluorotetrachloroethane (IV). Advantageously, III was isomerised to IV in the presence of I or II. The degree of isomerisation of the starting compounds I and III was 95-99%, the preparative yield of IV being 65-74%. The C-F bond energies in I-IVwere derived from correlation diagram and the physico-chemical aspects of the isomerisation are discussed.

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Compost leachate treatment using polyaluminium chloride and nanofiltration

Open Chemistry ◽

10.1515/chem-2017-0015 ◽

2017 ◽

Vol 15 (1) ◽

pp. 123-128 ◽

Cited By ~ 2

Author(s):

Marjana Simonič

Keyword(s):

Zeta Potential ◽

Isoelectric Point ◽

Oxygen Demand ◽

Treatment Method ◽

Aluminium Chloride ◽

Leachate Treatment ◽

Physico Chemical ◽

Pre Treatment ◽

Ph Range ◽

Compost Leachate

AbstractLaboratory scale filtration tests utilizing leachate were conducted to investigate fouling and filtration performance of nanofiltration membranes. The work presented in this study is conducted on real samples rather than model water. Physico-chemical analyses showed that the leachate contained a lot of organic substances, exceeding 20000 mg/L O2 expressed as chemical oxygen demand. Proper pre-treatment method must be chosen in order to reduce fouling index. Coagulation pre-treatment using poly-aluminium chloride was chosen. Two thin film polysulfone membranes were used, purchased by Osmonic Desal. The focus of this research is to assess the influence of the particle size and zeta-potential of the colloidal fraction in leachate on nanofiltration performance. The isoelectric point of both membranes was 4.7 and 4.3, respectively. The fouled membranes were negatively charged over the pH range with isoelectric point shifting to the left (lower pH) indicating the foulant material mainly not charged. It was confirmed by its zeta-potential, measured at -2 mV.

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Comparison of Polyferric Sulphate with Other Coagulants for the Removal of Algae and Algae-Derived Organic Matter

Water Science & Technology ◽

10.2166/wst.1993.0280 ◽

1993 ◽

Vol 27 (11) ◽

pp. 221-230 ◽

Cited By ~ 78

Author(s):

Jia-Qian Jiang ◽

Nigel J D. Graham ◽

Clive Harward

Keyword(s):

Laboratory Experiments ◽

Aluminium Chloride ◽

Ferric Sulphate ◽

Aluminium Sulphate ◽

Research Attention ◽

Aquatic Humic Substances ◽

Treatment Performance ◽

Coagulation Performance ◽

Physico Chemical ◽

Doc Concentration

This paper is concerned with the performance of a relatively new form of metal-iron coagulant, Polyferric Sulphate (PFS), which has received very little research attention to date. Laboratory experiments have been undertaken in which the coagulation performance of PFS, Ferric sulphate, Aluminium sulphate and Poly aluminium chloride have been studied using ‘model' waters containing single cultures of algae (Anabaenaflos-aquae and Asterionetta formosa) and other ‘model' waters prepared by mixing aquatic humic substances with Asterionella formosa at different concentration ratios. Physico-chemical variables such as colloid charge, floc number concentration and size distribution, DOC concentration and turbidity, have been determined to quantify treatment performance. The performance of PFS was found to be superior to the other coagulants and this was believed to be due to the presence of more highly charged cation species. For all coagulants there was an approximate stoichiometry between coagulant dose and the dissolved organic carbon concentratioa

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Physico-chemical study of complexing processes in AlCl3-L-H2O system where L – DPA, centralite, DNT, DBP

Butlerov Communications ◽

10.37952/roi-jbc-01/20-64-10-40 ◽

2020 ◽

Vol 64 (10) ◽

pp. 40-54

Author(s):

Rose F. Gatina ◽

◽

Olga V. Klimovich ◽

Yury M. Mikhailov ◽

◽

...

Keyword(s):

Electron Pair ◽

Chemical Study ◽

Ester Group ◽

Complex Compounds ◽

Aluminium Chloride ◽

Organic Components ◽

Double Salts ◽

Physico Chemical ◽

Donor Acceptor ◽

Trivalent Nitrogen

This work presents a method of powder components’ interaction, containing a trivalent nitrogen and other atoms with an undivided electron pair (UEP) with the aqueous solutions of complexing extragents. In the role of the latter, an aqueous solution of aluminium chloride was studied. Diphenylamine (DPA), centralite 1 (or diethyldiphenylurea), dinitrotoluene (DNT) and dibutylphthalate (DBP) were considered as organic components. A donor-acceptor mechanism of the reagents’ interaction is proposed, in which a section of a molecule of an organic component of powder, containing an element atom with UEP, acts as a donor of the electron pair; an aluminium ion with free p- and d-orbitals acts as an acceptor. It is the presence of both types of free orbitals that allows Al3+ ion to increase its coordination up to 6 in complex compounds, which it forms. The complex compounds (CCs) of aluminium chloride and powder components with the trivalent nitrogen atom and with other atoms with UEP were obtained in an aqueous medium. CCs were studied by the methods of the physico-chemical analysis such as conductance-measuring and titrimetric methods (complexation and agrentometric titration), chromatographic methods (thin-layer chromatography and gas-liquid chromate-graphy) and spectral methods (IR- and UV-spectrometry). The fragments of functional groups, involving in the formation of the intermolecular bonds such as amino group in DPA molecule, carbonyl group in centralite 1 molecule, nitro group in DNT molecule, ester group in DBP molecule and π-system of aromatic ring in all molecules of the considered organic components of powder, were revealed. It is found that a reason for an increase in a solubility of organic compounds of powder in water is the formation of complex compounds such as “double salts”. The optimal conditions for obtaining CCs such as “double salts” were determined. Later, this fact was applied for an extraction of these components from a powder composition.

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Effect of clariflocculator and pulsator based sedimentation technology and poly-aluminium chloride coagulant type on the efficiency of the water treatment plant

Water Science & Technology Water Supply ◽

10.2166/ws.2021.434 ◽

2021 ◽

Author(s):

Atul Maldhure ◽

Gajanan Khadse ◽

Pawan Labhasewar

Keyword(s):

Water Treatment ◽

Zeta Potential ◽

Chemical Properties ◽

Aluminium Chloride ◽

Aluminium Concentration ◽

Hydrolysis Mechanism ◽

Treated Water ◽

Water Treatment Plants ◽

Physico Chemical ◽

Incremental Addition

Abstract Polyaluminium chloride (PAC) with different basicity is used as a coagulant in most drinking water treatment plants (WTP). The aluminium concentration in PAC and its hydrolysis mechanism varied with the basicity of PAC. Incremental addition of PAC changes various Physico-chemical properties and turbidity removal mechanisms in water. Water treatment plants use the PAC concentration beyond its optimum dose without considering other aspects, including residual aluminium concentration. In the present work, the effect of high and medium basicity of PAC on different Physico-chemical properties like pH, zeta potential, and residual aluminium concentration of water was investigated. The pH of treated water decreases with the incremental addition of PAC, and an increase in zeta potential and residual aluminium concentration in treated water was evidenced. The change in pH after PAC addition is responsible for deciding the coagulation mechanism and efficiency of the coagulation process. pH reduction is comparatively more in high basicity PAC than medium basicity. PAC hydrolysis mechanism is controlled by the zeta potential of water and can be used as an alternative method to decide the optimum coagulant dose. The performance of clariflocculator and pulsator-based WTP was also evaluated for raw water from the same source. To reduce down the turbidity below the acceptable level, the coagulant requirement for clariflocculator based WTP is comparatively less than pulsator based WTP. The floc blanket in the pulsator gets disturbed with a slight change in the coagulant chemistry and quantity.

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Decoration of specific sites on freeze-fractured membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081565 ◽

1978 ◽

Vol 36 (2) ◽

pp. 140-141

Author(s):

H. Gross ◽

H. Moor

Keyword(s):

Pure Water ◽

Freeze Fracture ◽

Chemical Properties ◽

Surface Forces ◽

Sulfate Pentahydrate ◽

Copper Sulfate Pentahydrate ◽

Physico Chemical ◽

Water Of Hydration ◽

Small Container ◽

Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

Biochemical Society Symposium ◽

10.1042/bss0710097 ◽

2004 ◽

Vol 71 ◽

pp. 97-106 ◽

Cited By ~ 10

Author(s):

Mark Burkitt ◽

Clare Jones ◽

Andrew Lawrence ◽

Peter Wardman

Keyword(s):

Cytochrome C ◽

Hydroxyl Radical ◽

Redox Regulation ◽

Chemotherapeutic Agents ◽

Tyrosyl Radical ◽

Compound I ◽

Definitive Evidence ◽

Enhanced Production ◽

Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

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