Natural Leathers from Natural Materials: Progressing toward a New Arena in Leather Processing
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- 作者：Subramani Saravanabhavan ; Palanisamy Thanikaivelan ; Jonnalagadda Raghava Rao ; Balachandran Unni Nair ; and Thirumalachari Ramasami
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：February 1, 2004
- 年：2004
- 卷：38
- 期：3
- 页码：871 - 879
- 全文大小：271K
- 年卷期：v.38,no.3(February 1, 2004)
- ISSN：1520-5851
文摘
Globally, the leather industry is currently undergoingradical transformation due to pollution and dischargelegislations. Thus, the leather industry is pressurized tolook for cleaner options for processing the raw hides andskins. Conventional methods of pre-tanning, tanning andpost-tanning processes are known to contribute more than98% of the total pollution load from the leather processing.The conventional method of the tanning process involvesthe "do-undo" principle. Furthermore, the conventionalmethods employed in leather processing subject the skin/hide to a wide variation in pH (2.8-13.0). This results inthe emission of huge amounts of pollution loads such asBOD, COD, TDS, TS, sulfates, chlorides and chromium. In theapproach illustrated here, the hair and flesh removal aswell as fiber opening have been achieved using biocatalystsat pH 8.0, pickle-free natural tanning employing vegetabletannins, and post-tanning using environmentally friendlychemicals. Hence, this process involves dehairing, fiberopening, and pickle-free natural tanning followed byecofriendly post-tanning. It has been found that the extentof hair removal and opening up of fiber bundles iscomparable to that of conventionally processed leathers.This has been substantiated through scanning electronmicroscopic analysis and softness measurements.Performance of the leathers is shown to be on par withconventionally chrome-tanned leathers through physical andhand evaluation. The process also exhibits zero metal(chromium) discharge and significant reduction in BOD,COD, TDS, and TS loads by 83, 69, 96, and 96%, respectively.Furthermore, the developed process seems to beeconomically viable.