Chromium in the effluent is a major concern for tanning industry. Chemical precipitation methods are commonly employed for the removal of chromium but this leads to formation of chrome-bearing solid waste. Ion exchange and membrane separation methods are relatively expensive. In this study a chitosan bioadsorbent has been employed to remove chromium from tannery effluent. The effect of pH and chromium concentration showed chitosan to exhibit uptake of about 52 mg Cr (III)/g at optimum pH of 4.0. Langmuir and Freundlich models were applied. Increase of initial concentration of Cr resulted to a decrease in adsorption efficiency.
{"title":"BIOSORPTION OF CHROMIUM FROM TANNERY WASTEWATERS BY CHITOSAN OBTAINED FROM EXOSKELETON SHRIMP","authors":"Beatriz Jaramillo Colorado, Edisson Duarte Restrepo, Jesús Olivero Verbel","doi":"10.3407/RPN.V3I1.21","DOIUrl":"https://doi.org/10.3407/RPN.V3I1.21","url":null,"abstract":"Chromium in the effluent is a major concern for tanning industry. Chemical precipitation methods are commonly employed for the removal of chromium but this leads to formation of chrome-bearing solid waste. Ion exchange and membrane separation methods are relatively expensive. In this study a chitosan bioadsorbent has been employed to remove chromium from tannery effluent. The effect of pH and chromium concentration showed chitosan to exhibit uptake of about 52 mg Cr (III)/g at optimum pH of 4.0. Langmuir and Freundlich models were applied. Increase of initial concentration of Cr resulted to a decrease in adsorption efficiency.","PeriodicalId":153647,"journal":{"name":"Revista Productos Naturales","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132181775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two dibenzylbutane lignans, dihydroguairetic acid and austrobailigan-6 were isolated as mixture of their diastereoisomers from the bark ethanolic extract of Dugandiodendron argyrotrichum (Magnoliaceae), a colombian endangered species. Characterization was achieved by 1 H and 13 C NMR, DEPT, COSY, HMQC, HMBC and GCMS analysis. The diastereoisomer separation by GC and the diastereospecific fragmentation patterns in negative chemical ionization mass spectrometry (NCI-MS) spotlights on an interesting tool for stereochemical research.
{"title":"FRAGMENTACIÓN DIASTEREOESPECÍFICA EN NCI DE DOS LIGNANOS DIBENCILBUTÁNICOS DE LA CORTEZA DE Dugandiodendron argyrotrichum (MAGNOLIACEAE)","authors":"J. D. Vasquez","doi":"10.3407/RPN.V2I1.17","DOIUrl":"https://doi.org/10.3407/RPN.V2I1.17","url":null,"abstract":"Two dibenzylbutane lignans, dihydroguairetic acid and austrobailigan-6 were isolated as mixture of their diastereoisomers from the bark ethanolic extract of Dugandiodendron argyrotrichum (Magnoliaceae), a colombian endangered species. Characterization was achieved by 1 H and 13 C NMR, DEPT, COSY, HMQC, HMBC and GCMS analysis. The diastereoisomer separation by GC and the diastereospecific fragmentation patterns in negative chemical ionization mass spectrometry (NCI-MS) spotlights on an interesting tool for stereochemical research.","PeriodicalId":153647,"journal":{"name":"Revista Productos Naturales","volume":"259 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115207169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antonio Guzmán, Rubén Darío Torrenegra Guerrero, O. Rodríguez
The flavonoids rhamnocitrin (5,4’-dihydroxy-7-methoxyflavonol), sakuranetin (5,4’-dihydroxy-7-methoxyflavanone) and 3,8-dimethoxy-gossypetin (5,7,3’,4’-tetrahydroxy-3,8-dimethoxyflavone) were isolated and purified from Chromolaena subscandens’ leaves using column chromatography and thin layer chromatography methods. These substances were identified on the basis of their physical properties (melting point and Rf value), qualitative chemical reactions and spectroscopic techniques UV and NMR (experiments 1H, 13C, 1H-1H COSY, HMQC and HMBC), according to their complexity.
{"title":"FLAVONOIDES DE Chromolaena subscandens (Hieron.) R.M. King & H. Rob.","authors":"Antonio Guzmán, Rubén Darío Torrenegra Guerrero, O. Rodríguez","doi":"10.3407/RPN.V2I1.15","DOIUrl":"https://doi.org/10.3407/RPN.V2I1.15","url":null,"abstract":"The flavonoids rhamnocitrin (5,4’-dihydroxy-7-methoxyflavonol), sakuranetin (5,4’-dihydroxy-7-methoxyflavanone) and 3,8-dimethoxy-gossypetin (5,7,3’,4’-tetrahydroxy-3,8-dimethoxyflavone) were isolated and purified from Chromolaena subscandens’ leaves using column chromatography and thin layer chromatography methods. These substances were identified on the basis of their physical properties (melting point and Rf value), qualitative chemical reactions and spectroscopic techniques UV and NMR (experiments 1H, 13C, 1H-1H COSY, HMQC and HMBC), according to their complexity.","PeriodicalId":153647,"journal":{"name":"Revista Productos Naturales","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133067519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Opinion Revista de Productos Naturales","authors":"O. Benavides","doi":"10.3407/RPN.V1I1.4","DOIUrl":"https://doi.org/10.3407/RPN.V1I1.4","url":null,"abstract":"","PeriodicalId":153647,"journal":{"name":"Revista Productos Naturales","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132924608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"BIENVENIDOS A LA REVISTA PRODUCTOS NATURALES","authors":"J. H. I. Martínez","doi":"10.3407/RPN.V1I1.2","DOIUrl":"https://doi.org/10.3407/RPN.V1I1.2","url":null,"abstract":"","PeriodicalId":153647,"journal":{"name":"Revista Productos Naturales","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115290446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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