Alternative process for recovery of chrome(III)-effluents / Jaime Cot in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 92, N° 4 (07-08/2008)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 92, N° 4 (07-08/2008) . - p. 139-149 Titre : Alternative process for recovery of chrome(III)-effluents Type de document : texte imprimé Auteurs : Jaime Cot, Auteur ; Agusti Marsal, Auteur ; Albert M. Manich, Auteur ; Pedro J. Celma, Auteur ; F. Fernandez, Auteur ; J. Cot-Gores, Auteur Année de publication : 2008 Article en page(s) : p. 139-149 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Bisulfite de sodium Eaux usées -- Epuration Eaux usées -- Teneur en chrome Fluidisation Glucose Gommes et résines Oxydoréduction Peroxyde d'hydrogène Le peroxyde d'hydrogène (H2O2), communément appelé eau oxygénée ou encore perhydrol (appellation industrielle), est un composé chimique liquide et visqueux, aux puissantes propriétés oxydantes (il est aussi réducteur). C'est donc un agent blanchissant efficace qui sert de désinfectant et (à haute concentration) d'oxydant ou monergol dans les fusées spatiales. Récupération (Déchets, etc.) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : This scheme aims to set up an alternative process to recover chrome(III) from tannery effluents. The use of the conventional technique of alkaline precipitation (magnesium oxide) of chromium(III) is well known from the literature and is in daily practice in tanneries worldwide. This technique may in fact represent the cheapest treatment nowadays; however, the latest economic studies have revealed the influence of parameters that could significantly alter investment costs and thus open a door to alternative processes. The main problems that the precipitation technique carries with it are : - a) the presence of highly masked chrome(III) complexes, difficult to precipitate even in alkaline medium. - b) the speed of precipitation and the density of the precipitate can be a major problem. Sometimes, the application of heat is required. - c) filtration of the precipitate and subsequent drying to remove possibly 30% of the water content of the chromecake (various techniques are used). - d) recovered chrome(III) obtained by re-dissolving the cake with sulphuric acid and final adjustment to 33°Sch basicity can occlude large amounts of highly masked chrome (III) complexes which, in turn, produce uneven dyed grain surfaces ; limiting dyeing to dark shades. Furthermore, basic factors such as energy consumption, the lengthy nature of the overall process, the simple but numerous stages, and limited coverage of fashion colours indicate that an alternative process is possible. This part of the work aims to recover the chromium1 of wastewater coming from the various chrome using processes and, at the same time, to get an effluent that can be used directly without complementary treatments. It is important to give a clearer and detailed idea of the developed process. Note de contenu : - INTRODUCTION : Resin selection - Wastewater oxidation process - Wastewater loading - Chromium reduction process - EXPERIMENTAL PROCEDURE : Equipment and reagents used - Resin Amberlite IRA-96 - Sample preparation - Wastewater load and reduction - Fluidisation system - Fluidisation mechanism (see appendix for symbols) - Calculation off luidisation for the pilot plant - Reduction in a batch system - Table 1 : Amberlite IRA-96 resin characteristics - Table 2 : Optimal operation conditions - Table 3 : Chromium recovered using acid hydrogen peroxide as reducer - Table 4 : Chromium recovered using sodium bisulphite as reducer - Table 5 : Chromium recovered using glucose as reducer En ligne : https://drive.google.com/file/d/1k7CnOQf4zEsbildKyaGXxsI_elC93m2i/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38963 [article]

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Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 4 / Agusti Marsal in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 88, N° 6 (11-12/2004)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 88, N° 6 (11-12/2004) Titre : Auxiliary agents with non-swelling capacity used in pickling-tanning processes - Part 4 Type de document : texte imprimé Auteurs : Agusti Marsal, Auteur ; Ramón Palop, Auteur ; V. Frias, Auteur ; M. D. de Castellar, Auteur ; Pedro J. Celma, Auteur ; Albert M. Manich, Auteur Année de publication : 2004 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents anti-gonflement Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux de moutons Picklage Le picklage consiste à faire absorber à la peau en tripe une quantité importante d'acide, en présence de sel neutre (NaCl) pour réprimer le gonflement que provoquerait l'acidité du milieu. Post-tannage Résistance à la déchirure Résistance à la traction Tannage au chrome Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The reduction in the use of salt in pickling due to the application of different chemicals with non-swelling capacity - polyacrylic acid, naphthol 3-6-disulphonic acid, p-hydroxydiphenyl sulphonic acid and a blend of naphthalene and naphthol sulphonic acids- has been studied in previous papers.1-3 These chemicals were applied in the pickling process either alone or with small amount of salt. In Part I1, it was confirmed that the blend of naphthalene and naphthol sulphonic acids at an offer of 3% (on pelt weight) and at a salinity of 2°Bé could be a valid alternative since it adequately prevented the swelling of hides. Tanning treatments with conventional chromium salts yielded the correct shrinkage temperatures. In Part II2 it was observed that the conventional tanning process of hides pickled with sulphuric acid and 3% (on pelt weight) of the blend of naphthalene and naphthol sulphonic acids at a salinity of 2°Bé yielded leathers that could be acceptable as far as physical properties and handle were concerned. However; these leathers showed an irregular stratigraphic distribution of Cr2O3 and a marked colour difference between grain and flesh sides. Optimization of the tanning process of these hides confirmed that the best results were obtained with a strongly masked chromium salt with a very low basicity. In Part III3, the possible application of chemicals with non-swelling capacity to reduce the use of salt in the pickling process of sheepskins was studied. In this case, the use of a strongly masked chromium salt with a very low basicity in the tanning process was not necessary since conventional tanning salts were adequate. The best results in terms of non-swelling capacity, shrinkage temperature of the tanned hides, conductivity and Chemical Oxygen Demand of the residual baths were achieved under the following conditions: 2% p-hydroxydiphenyl sulphonic acid (salinity 2°Bé); 2% naphthol 3-6-disulphonic acid (salinity 2°Bé) and 4% polyacrylic acid (salinity 2°Bé). Note de contenu : - AIM OF THE WORK - EXPERIMENTAL PROCEDURE : Pickle and tannage - Process evaluation - RESULTS : Swelling of the pickled/tanned skins - Evaluation of the pickling and tanning residual baths - Leather characteristics - APPENDIX : Chemicals utilized in this work - Table 1 : Comparative study between pickling processes - Table 2 : Post-tanning processes - Table 3 : Thickness variation (%) after pickling/tanning in relation to bating - Table 4 : Evaluation of the pickling and tanning residual baths - Table 5 : Leather characteristics as a function of the pickling process - Table 6 : Tensile strength (IUP 6) - Table 7 : Tear Resistance (IUP 8) - Table 8 : Measurement of distension and strength of the grain by the Ball Burst Test (IUP 9) En ligne : https://drive.google.com/file/d/1KGJNb1N6N3BJ-enzwHjtuzRzbeI92kqw/view?usp=shari [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39617 [article]

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Determination of the collagen thermal transitions in chrome leather by TMA / Albert M. Manich in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVIII, N° 7 (07/2003)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVIII, N° 7 (07/2003) . - p. 279-284 Titre : Determination of the collagen thermal transitions in chrome leather by TMA Type de document : texte imprimé Auteurs : Albert M. Manich, Auteur ; Teresa Bosch, Auteur ; Josep Carilla, Auteur ; Jaime Cot, Auteur ; Agusti Marsal, Auteur ; Joan Sala, Auteur ; Pedro J. Celma, Auteur Année de publication : 2003 Article en page(s) : p. 279-284 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The collagen thermal transitions of bovine chrome leather were studied by thermomechanical analysis (TMA). The application of dynamical stresses under transverse compressive penetration and longitudinal extension modes allows us to determine the glass-transition temperature of collagen in conditioned and dried states and the denaturation temperature in dried state of collagen. The results agree with those obtained by differential scanning calorimetry (DSC) and thermogravimetry (TGA). The thermal transitions determined by TMA in transverse compressive penetration mode showed a good relationship with the origin and final application of leather. En ligne : https://drive.google.com/file/d/1Fs6tClG8Ajqq9TvgOQeQmWgFg2koxXqU/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4146 [article]

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Minimization of industrial wastes-adding value to collagenic : Adding value to collagenic materials procter memorial lecture / J. Cot in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 3 (05-06/2003)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 87, N° 3 (05-06/2003) . - p. 91-97 Titre : Minimization of industrial wastes-adding value to collagenic : Adding value to collagenic materials procter memorial lecture Type de document : texte imprimé Auteurs : J. Cot, Auteur ; Agusti Marsal, Auteur ; Albert M. Manich, Auteur ; Pedro J. Celma, Auteur ; Rigoberto Choque, Auteur ; Luisa F. Cabeza, Auteur ; L. Labastida, Auteur ; J. Lopez, Auteur ; J. Salmeron, Auteur Année de publication : 2003 Article en page(s) : p. 91-97 Langues : Anglais (eng) Catégories : Agents de tannage Chrome trivalent Colorants Cuirs et peaux -- Déchets Déchets -- Réduction Huiles et graisses Polyacryliques Polyuréthanes Statistiques Tannage -- Déchets Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Our research is in the area of minimisation of industrial waste in the leather industry. This contribution is concerned with the processing of chromed collagen residues produced at each of the different stages of production. These are : - group I : chromed residuals - tanning and drying stage - crust state - group II : chromed residuals + fatty matter - fatliquoring stage - group III : chromed residuals + fatty matter + retanning agents - retanning stage - group IV : chromed residuals + fatty matter + retanning agents + dyestuff - dyeing stage - group V : chromed residuals + fatty matter + retanning agents + dyestuff + acrylic and /or polyurethanes - finish stage Group V residues represent the highest percentage of the total volume of residues and they are also the most complex. The group includes the trimmings from industrial manufacturers of leather products such as footwear, clothing and upholstery. Chromed collagen residues are those stabilised or crosslinked with chromium (III) salts which block any later treatment to obtain gelatine using conventional methods. A large part of this type of residue is used for the production of agglomerates known as regenerated leather, mixing with latex in dutch-piles, from which various articles are manufactured. Note de contenu : - STASTISTICAL TREATMENT OF THE RESULTS : Experimental design - EVOP design - The relationship between NaOH concentration, temperature and Bloom degree - Inclusion of the effect of temperature and of time on the Bloom degree - INDUSTRIAL APPLICATION - Table A : Variable levels of the box and hunter design - Table B : Experimental plan randomly ordered - Table C : First EVOP cycle design to explore the optimum Bloom zone : H2O2 remained constant at 1 mL - Table D : Second EVOP cycle design to explore the optimum Bloom zone : H2O2 remained constant at 1 mL - Table E : Experiments used to explore the functional relationship between the NaOH concentration and Bloom degree En ligne : https://drive.google.com/file/d/1ZN4xdrByWrdVJUfF_R7kUw77M4hKfcNs/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39781 [article]

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Processing of collagenic residues. Isolation of gelatin by the action of peroxochromates / Jaime Cot in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIV, N° 4 (06/1999)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCIV, N° 4 (06/1999) . - p. 115-128 Titre : Processing of collagenic residues. Isolation of gelatin by the action of peroxochromates Type de document : texte imprimé Auteurs : Jaime Cot, Auteur ; Albert M. Manich, Auteur ; Agusti Marsal, Auteur ; Maria Fort, Auteur ; Pedro J. Celma, Auteur ; Robert Carrio, Auteur ; Rigoberto Choque, Auteur ; Luisa F. Cabeza, Auteur Année de publication : 1999 Article en page(s) : p. 115-128 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The experience of our research group with topics related to the dechroming(III) to chromium(VI) by peroxides in alkaline conditions, allowed us to know in-depth the reaction mechanisms. The formation in situ of some peroxochromates (containing up to 2,5 groups peroxo for each atom of chromium), unstable and with a great owidizing potential, is fundamental in the process of gelatin isolation. It has been demonstrated that the chromium-containing collagenic wastes that had bee previously dechromed by this method produce a gelatin with better yield, quality and in a much shorter treatment, compared with conventional methods described in the literaure. The residual chrome content in the gelatin can be eliminated using tangencial ultrafiltration and the reverse osmosis techniques. Furthermore, the chromium (VI) is recovered by ion-exchange resins and can be re-used in tanneries. Finally, physico-chemical characteristics of the isolated gelatins were evaluated. Note de contenu : - EXPERIMENTAL : First experimental design - Second experimental design - Activity of the peroxochromates generated in situ - RESULTS AND DISCUSSION : Applications of the isolated gelatin - Future perpectives En ligne : https://drive.google.com/file/d/1mf5XWt0cvDqFdzZhQVdLcmbnTosrgp3h/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4455 [article]

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The enzyme activity of trypsen on sheepskin trimmings in a two-step collagen extraction process / F. Fernandez-Hervas in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CII, N° 1 (01/2007)  

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Transformation plant for converting chromium waste into chemical products for the leather industry / Jaime Cot in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 3 (03/2008)  

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Treatment of sheepskin chrome shavings. Isolation of high value protein products and reuse of chromium in the tanning process / Luisa F. Cabeza in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCIV, N° 7 (09/1999)  

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