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Exploring the oxidation of chromium(III) to chromium(VI) by unsaturated lipids in leather / Yu Congzheng in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 91, N° 3 (05-06/2007)
[article]
Titre : Exploring the oxidation of chromium(III) to chromium(VI) by unsaturated lipids in leather Type de document : texte imprimé Auteurs : Yu Congzheng, Auteur ; Ma Xingyuan, Auteur ; Liu Pengjie, Auteur ; Sun Genxing, Auteur ; Qian Yiping, Auteur Année de publication : 2007 Article en page(s) : p. 116-122 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chrome hexavalent
Chrome trivalent -- Oxydation
Composés insaturés
Cuirs et peaux -- Analyse
Huile d'arachide
Lipides
Oléique, AcideL'acide oléique vient du latin oleum et veut dire huile. C'est le plus abondant des acides gras monoinsaturés à chaîne longue dans notre organisme. Sa formule chimique brute est C18H34O2 (ou CH3(CH2)7CH=CH(CH2)7COOH). Son nom IUPAC est acide cis-9-octadécénoïque, et son nom court de lipide est 18:1 cis-9. La forme saturée de cet acide est l'acide stéarique.
On le symbolise par les nombres 18:1 pour indiquer qu'il possède 18 atomes de carbone et une liaison éthylénique. Pour indiquer la position de la double liaison, on préfère indiquer le nombre de carbones entre le dernier carbone (n° 18) et le carbone où commence la double liaison (n° 9), d'où 18 - 9, qu'on écrit n - 9, en désignant par n le nombre de carbones de la chaîne. L'acide oléique est donc un acide gras insaturé, plus précisément monoinsaturé.
La double liaison agit sur la forme de la molécule et des triglycérides qu’elle forme avec le glycérol. Comme la molécule ne peut pas pivoter autour de C = C, la chaîne est beaucoup moins flexible que l’acide stéarique et ne peut pas former de boule. Les molécules des esters de cet acide sont beaucoup moins compactes que la tristéarine: ces sont des huiles.
À la température de notre corps c'est un liquide (huile), qui ne se solidifie qu'à 13,4 °C.Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : This work has broken free from the framework of the traditional leather-making process and taking a new method, has explored the influence of the double bonds of unsaturated lipids on the level of chromium(VI) in chrometanned leather. The following parameters were controlled during the experiment: temperature, humidity, time and the pH. Checking the iodine value and peroxide value of the lipids regularly and determining the structural changes by infrared, the experiment demonstrates the oxidation mechanism of chromium(III) to chromium(VI) by unsaturated lipids in chrome-tanned leather. Note de contenu : - EXPERIMENTAL PROCEDURE : Experimental process and method (the following experiments were carried out simultaneously) - Analysis and Determination
- RESULTS AND DISCUSSION : Results and discussions of different oil systems - Analysis of the oleic acid system by Fourier Transform Infrared (FTIR)
- Table 2 : Results for oleic acid system
- Table 3 : Results for peanut oil system
- Table 4 : Results for oleic acid system
- Table 5 : Cr(VI) contents in control test
- Table 6 : Results of before and after extraction on the 8th day
- Table 7 : Chromium(VI) contents of different systemsEn ligne : https://drive.google.com/file/d/1D_aH5SMQVgoDUQ-BJ3YS0RXik4Ucn6GU/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39029
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 91, N° 3 (05-06/2007) . - p. 116-122[article]Facile preparation of hierarchical porous polydopamine microspheres for rapid removal of chromate from the wastewater / Lin Xiang in JOURNAL OF LEATHER SCIENCE AND ENGINEERING, Vol. 2 (Année 2020)
[article]
Titre : Facile preparation of hierarchical porous polydopamine microspheres for rapid removal of chromate from the wastewater Type de document : texte imprimé Auteurs : Lin Xiang, Auteur ; Jiayou Lin, Auteur ; Qin Yang, Auteur ; Shaojian Lin, Auteur ; Sheng Chen, Auteur ; Bin Yan, Auteur Année de publication : 2020 Article en page(s) : 10 p. Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Adsorption
Chrome hexavalent
Chrome trivalent
Eaux usées -- Décontamination
Microsphères
PolydopamineIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Cr(VI) containing industrial wastewaters are highly toxic and carcinogenic, and severely threats living creatures and the environment. Therefore, it is highly desired yet challenging to develop an available and economical adsorbent for simultaneously detoxifying Cr(VI) anions to Cr(III) ions and removing them from the wastewater. Here we propose a facile method for rapid removal of Cr(VI) ions from the wastewater by using a synthetic polydopamine microsphere (PPM) adsorbent with hierarchical porosity. The as-prepared PPM exhibits high Cr(VI) removal capacity of 307.7 mg/g and an outstanding removal efficiency. They can effectively decrease the Cr(VI) concentration to lower than 0.05 mg/L well below the limits for drinking water standard of WHO regulations in 60 s at pH 2. More importantly, PPMs can reduce the lethal Cr(VI) anions to Cr(III) ions with low toxicity, and simultaneously immobilize them on the matrices of PPMs. Note de contenu : - MATERIALS AND METHODS : Material - Synthesis of PPMs - PPMs material characterization - Cr(VI) removal experiments
- RESULTS AND DISCUSSION : Synthesis and characterizations of the PPMs - High Cr(VI) removal capacity of PPMs - Rapid Cr(VI) adsorption kinetics of PPMs - Highly selectivity of PPMs to Cr(VI) from complex wastewater - Easy regeneration and recovery of adsorbents for recycling - Cr(VI) adsorption mechanisms of PPMs via reduction and immobilization
- Table 1 : Fitting parameters of thermodynamic adsorption under different temperatures
- Table 2 : The thermodynamic parameters of △H0, △S0 and △G0
- Table 3 : Kinetic adsorption model fitting dataDOI : https://doi.org/10.1186/s42825-020-00036-x En ligne : https://link.springer.com/content/pdf/10.1186/s42825-020-00036-x.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37455
in JOURNAL OF LEATHER SCIENCE AND ENGINEERING > Vol. 2 (Année 2020) . - 10 p.[article]Inhibitory mechanism of hexavalent chromium formation in chrome-tanned leather with combined inhibitors / Koki Ogata in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 5 (09-10/2019)
[article]
Titre : Inhibitory mechanism of hexavalent chromium formation in chrome-tanned leather with combined inhibitors Type de document : texte imprimé Auteurs : Koki Ogata, Auteur ; Shunji Hattori, Auteur ; Koji Takahashi, Auteur Année de publication : 2019 Article en page(s) : p. 253-259 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chimie analytique
Chrome hexavalent
Inhibiteurs (chimie)
Statistique
Tannage au chromeIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The perfect inhibition of Cr6+ formation in Cr-tanned leather has been reported using combined inhibitors consisting 3(2)-t-butyl-4-hydroxyanisole (BHA), ascorbic acid (AsA), and collagen peptide (CP-9). In this study, the inhibitory mechanism of the combined inhibitors was investigated with respect to: (i) Inhibiting the conversion of Cr3' to Cr6+ by scavenging lipid radicals and peroxy radicals in free lipid of Cr-tanned leather; (ii) strengthening the reductivity within Cr-tanned leather; and (iii) stabilising Cr3+ complexes by coordination with CP-9. Electron spin resonance (ESR) of free lipid extracted from the Cr-tanned leather treated with combined inhibitors showed that free radicals considerably reduced with BHA and AsA. AsA markedly depressed peroxide value (POV), indicating strong effectiveness of the reducing action of AsA. The CP-9-added extract with 0.1 mol/L potassium phosphate buffer (pH 5.5) of the Cr-tanned leather before changing from pH5.5 to 8.0 showed that the conversion of Cr3+ to Cr6+ showed concentration-dependent inhibition, suggesting stabilisation through CP-9 coordination. Therefore, perfect inhibition of Cr6+ formation in Cr-tanned leather using combined inhibitors was concluded to be caused by the multiple inhibitory actions of BHA, AsA, and CP-9, such as radical scavenging, radical scavenger regeneration, reducing action, and Cr3+ stabilisation. Note de contenu : - MATERIALS AND METHODS : Materials - Preparation of free and bound lipids in Cr leather - ESR - Peroxide value (POV) measurements - Carbonyl value (COV) measurement - Estimation of stabilisation of Cr3+ complex with CP-9 - Analytical methods - Statistical analysis
- RESULTS : Radical scavenging action of inhibitors - Stabilisation of free Cr3+ complexEn ligne : https://drive.google.com/file/d/1LhJTnvaHNvu7PeQaURJOAhIvfRmLXZAv/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33000
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 103, N° 5 (09-10/2019) . - p. 253-259[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 21222 - Périodique Bibliothèque principale Documentaires Disponible Investigation on reducing chromium quantity in chromium containing wastes from leather industry using oyster mushroom (pleurotus ostreatus) / Eser Eke Bayramoglu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXV, N° 1 (01/2020)
[article]
Titre : Investigation on reducing chromium quantity in chromium containing wastes from leather industry using oyster mushroom (pleurotus ostreatus) Type de document : texte imprimé Auteurs : Eser Eke Bayramoglu, Auteur ; Anil Ozcelik, Auteur ; Mehmet Cetin, Auteur ; Erkan Eren, Auteur Année de publication : 2020 Article en page(s) : p. 3-9 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Absorption
Champignons et constituants
Chrome hexavalent
Déchets -- Réduction
Tannage -- Déchets
Wet-blue (tannage)Peau tannée au chrome (le chrome donne une couleur bleue)Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : In the leather industry, the wastes after the wet blue phase, which are created by the shaving process, are one of the substances that cause environmental pollution. Most of the time, these wastes are buried and may, under some circumstanses, cause serious environmental pollution problems. In this study, the chromium in wet blue shaved waste is to be minimized by using oyster mushrooms (Pleurotus ostreatus). Wet blue shaved wastes were mixed with 0.5%, 1%, 1.5% and 2% doses into the growth medium. After the oyster mushroom growth, the consumption of chromium from the growth media and uptaken by the mushrooms were investigated with Ege University Argefar Lab.'s House Method using a ICP-MS. Note de contenu : - EXPERIMENTAL : Materials - Methods
- ASSEMBLY OF TESTS : Preparation of growing environments - Sterilization and mycelium grafting - Incubation and harvest - Statistical evaluationDOI : https://doi.org/10.34314/jalca.v115i1.1462 En ligne : https://drive.google.com/file/d/12w7v_f2HZ2SRndTL1uVnanZPiHCFV8QW/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33391
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Code-barres Cote Support Localisation Section Disponibilité 21484 - Périodique Bibliothèque principale Documentaires Disponible Kinetic studies of glutamic acid oxidation by hexavalent chromium in presence of surfactants / Ankita Basu in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 49, N° 6 (11-12/2012)
[article]
Titre : Kinetic studies of glutamic acid oxidation by hexavalent chromium in presence of surfactants Type de document : texte imprimé Auteurs : Ankita Basu, Auteur ; Sumanta K. Ghosh, Auteur ; Saha Rumpa, Auteur ; Aniruddha Ghosh, Auteur ; Tuhin Ghosh, Auteur ; Kakali Mukherjee, Auteur ; Subhendu Sekhar Bhattacharyya, Auteur ; Bidyut Saha, Auteur Année de publication : 2012 Article en page(s) : p. 481-487 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chrome hexavalent
Cinétique chimique
Glutamique, AcideL'acide glutamique ou glutamate (la forme anionique de l'acide glutamique) est l'un des 20 acides-α-aminés naturels constituant les protéines. Sa chaîne latérale contient un résidu carboxyle, ce qui en fait un acide aminé « acide », dicarboxylique, polaire.
Oxydation
SurfactantsIndex. décimale : 668.1 Agents tensioactifs : savons, détergents Résumé : Hexavalent chromium is a widespread environmental contaminant and a known human carcinogen. It is a very important to remove toxic Cr(VI) from industrial waste water. In human body Cr(VI) is reduced to Cr(III). Effective bio-molecule present in body contains a number of different functional groups. Kinetics of reduction of Cr(VI) by an important amino acid, glutamic acid in micellar media have been studied spectrophotometrically. Micellar media is a testing enviroment to establish the mechanistic paths of reduction of Cr(VI) to Cr(III). The catalyst and suitable surfactants enhance the reduction of Cr(VI). Note de contenu : - EXPERIMENTAL AND METHODS : Procedure and kinetics measurements - Product analysis
- RESULTS AND DISCUSSION : Dependence of [bipy]y - Dependence on the substrate [glutamic acid]T - Dependence on [H+] - Effect of surfactants - Evidence for the formation of free radicals
- MECHANISM AND INTERPRETATIONPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16535
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Code-barres Cote Support Localisation Section Disponibilité 14334 - Périodique Bibliothèque principale Documentaires Disponible Leather ageing and hexavalent chromium formation as a function of the fatliquoring agent. Part II : Chrome retanned leathers / Ramón Palop in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 92, N° 6 (11-12/2008)
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