Management of tannery wastewaters: treatment of spent chrome tanning bath and vegetable tanning effluents

The leather industry is one of the heavy-polluting and hazardous industries that is creating toxic and harmful effects on the environment and human health by producing waste chemicals, tannery effluents, and various pollutants. Moreover, Tanning is the required stage to convert raw skin to durable and sustainable skin but most of the chemicals, salts, organic and inorganic toxic pollutants are produced. In commercial practices, Chrome tanning is the highly employed approach that uses a large number of basic chromium salts that becomes the major source of chromium pollutant in the environment. Chromium salt is not only harmful to the environment and ecology but also harms the human body such as causing respiratory problems, infertility and birth defects, skin and lung cancer of the workers. This article has presented two alternatives eco-friendly greener approaches of chrome tanning and waste management technique to reduce the toxic effect on the environment and human health. Firstly, to get rid of these harmful effects, the possible remedy of environmental and human health problems may be considered the vegetable tanning process. Vegetable tanning uses tannins (a class of polyphenol astringent chemicals), which occur naturally in the bark and leaves of many plants. Secondly, chrome tanning associate with ultrasound having a frequency range of 20–100 kHz is commonly employed for enhancing the physical processes and for performing chemical reactions. The basic principle associated with the process is an ultrasonic cavitation in dissolved media. Ultrasound decreases the consumption of conventional water and chemicals because it can also function as a physical activator resulting reduction in environmental pollution which is a prime concern nowadays to approach greener leather technology and eco-friendly leather processing. Furthermore, the possible waste management technique of chrome tanning helps to prevent pollution and ensure eco-friendly green technology of leather processing. Therefore, vegetable tanning and chrome tanning associated with ultrasound having proper waste management will be the viable and sustainable options for the tanners in the forthcoming future.

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Pine Tannin Extraction from Residues of Pine Forest Exploitation

Journal of the American Leather Chemists Association ◽

10.34314/jalca.v115i6.3821 ◽

2020 ◽

Vol 115 (6) ◽

pp. 215-221

Author(s):

Mireia Conde ◽

Felip Combalia ◽

Lluis Ollé ◽

Anna Bacardit

Keyword(s):

Pine Forest ◽

Forest Exploitation ◽

Chrome Tanning ◽

Vegetable Extract ◽

Short Period ◽

Tanning Process ◽

Chemical Products ◽

Forestry Residues ◽

Vegetable Tanning ◽

Tannin Extraction

The main aim of this study is to use the vegetable extract obtained from the residues of pine forest exploitation as a source of tannins that, acting both as a tanning and retanning agent, can replace other vegetable extracts and chrome in leather tanning. The study thus proposes a bio resource more sustainable to use in tanning process that avoids the use of chemical products that are detrimental to our health and can have an impact on the biodegradable nature of the final tanned leather. Furthermore, in addition to the benefits of using a new, fully biodegradable tanning material (Biodegradability of vegetable tanned leather is poor than chrome tanned leather), this is a locally sourced product, which allows the carbon footprint to be notably reduced (Vegetable tanning contributes more carbon foot print than chrome tanning). Additionally, it should be possible to add value to forestry residues over a short period of time, which would undoubtedly contribute to improving forest management in Spain and would also be beneficial in many ways.

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Evaluation Abu-Dleek Sheep Leathers Properties

International Journal of Zoology and Animal Biology ◽

10.23880/izab-16000201 ◽

2020 ◽

Vol 3 (1) ◽

pp. 1-3

Author(s):

Nasr AI

Keyword(s):

Chemical Properties ◽

Physical And Chemical Properties ◽

Arid Conditions ◽

Hot Climate ◽

Chrome Tanning ◽

Wide Range ◽

Animal Hair ◽

Vegetable Tanning ◽

Physical And Chemical ◽

And Chemical Properties

Abu-Dleek sheep are from animal hair producers and live under arid conditions and hot climate. This study aims to evaluate the physical and chemical properties of Abu-Dleek tanned leathers. Fifteen sheep skins were collected and divided into three tanning groups; chrome tanning, vegetable tanning with quebracho and vegetable tanning with mimosa. After tanning, all tanned leathers were tested physically and chemically. Data showed increments in tensile strengh, tearing strengh, bursing stretch, permeabiliy of water vapor, pH and ash values of chrome tanned leathers versus vegetable tanned leathers. The results declared the superurity of the chrome tanned leathers’ quality, while quebrcho tanned leathers’ quality was surpased mimosa tanned leathers. It could be concluded the convenient of Abu-Dleek tanned leathers to be used in a wide range of manufacuring purposes like garments, bags and lining.

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An insight into artisanal leather making in Ghana

Journal of Leather Science and Engineering ◽

10.1186/s42825-020-00039-8 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Miriam Appiah-Brempong ◽

Helen M. K. Essandoh ◽

Nana Yaw Asiedu ◽

Samuel Kwame Dadzie ◽

Francis Warings Yao Momade

Keyword(s):

Traditional Method ◽

Scientific Research ◽

Developing Nations ◽

Manufacturing Processes ◽

Production Processes ◽

Rural Livelihood ◽

Chrome Tanning ◽

Scientific Principles ◽

Vegetable Tanning ◽

Insight Into

Abstract The production of leather from animal skins and hides through tanning processes began in the pre-historic ages. Despite the origination of new leather making techniques such as chrome tanning which is being employed extensively today, the traditional method of leather production primarily through vegetable tanning is still being practised mostly in artisanal tanneries in developing nations including Ghana. Artisanal leather making, thus, contributes beneficially to rural livelihood. Nevertheless, the growth of this sector has been stifled by the lack of innovative technologies to enhance productivity. This challenge could be partly linked to the knowledge gap on the scientific principles governing artisanal leather production processes. This study, therefore, elaborates on various process steps and materials employed in traditional leather making in Ghana and the scientific principles underlying each of the processes. It also makes a comparison between traditional and modern leather manufacturing processes and identifies knowledge and technological gaps which would inspire in-depth scientific research into artisanal leather making. Graphical abstract

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A Review of Eco-Friendly Preservative and Bio-Tannin Materials Using Powdered Barks of Local Plants for the Processing of Goatskin

International Research Journal of Science and Technology ◽

10.46378/irjst.2019.010103 ◽

2019 ◽

pp. 13-20

Author(s):

Franco John Unango ◽

Ramesh Duraisamy ◽

Karthikeyan M Ramasamy

Keyword(s):

Pollution Control ◽

Raw Material ◽

Leather Industry ◽

Future Studies ◽

Chromium Vi ◽

Chrome Tanning ◽

Local Plants ◽

Vegetable Tanning ◽

Chromium Salt ◽

Salt Preservation

Skin is a raw material which is considered as the heart of leather making process. Skin falls vulnerable upon the flayed of the animals and is seriously invaded by bacteria if it is not well protected. Curing and preservation of raw stock resist putrefaction and reserve leather quality. Worldwide, most commonly used skin preservation is by using table salt which is accused of polluting the environment by increasing soil salinity, affecting water body, releasing more than 40% dissolved solids and 55% chlorides etc. Further, on the side of leather tanning, 80-90% of all leathers is manufactured by tanning with basic chromium (III) salt, because of its excellent features and is also solemnly accused that; its safety record is cautionary, uncontrolled emission of chromium (VI) and it is a limited natural resources. Pollution control authorities of many countries are imposed severe restrictions on both salt preservation and chrome tanning forcing the tanners and researchers to look for possible alternative ways that are naturally abundant, easily obtainable, low priced, eco-friendly and offer competitive with existing tanned leather performances. The critical reviewed was targeting the recent alternatives trends to skin/hides salt preservation as well as vegetable tanning as a possible way to replace the use of basic chromium salt for the sustainability of leather industry and to further suggest another preservative and vegetable plant to be used in future studies.

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SYNTHETIC TEXTILE WASTEWATERS TREATMENT BY COAGULATION/FLOCCULATION USING FERRIC SALT AS COAGULANT

Environmental Engineering and Management Journal ◽

10.30638/eemj.2017.206 ◽

2017 ◽

Vol 16 (9) ◽

pp. 1881-1889 ◽

Cited By ~ 2

Author(s):

Rui A.R. Boaventura ◽

Carmen S.D. Rodrigues ◽

Luis M. Madeira

Keyword(s):

Ferric Salt ◽

Wastewaters Treatment ◽

Textile Wastewaters

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The Colloid Content of Vegetable Tanning Extracts

Journal of Industrial & Engineering Chemistry ◽

10.1021/ie50147a005 ◽

1922 ◽

Vol 14 (3) ◽

pp. 191-195 ◽

Cited By ~ 8

Author(s):

ARTHUR W. THOMAS ◽

STUART B. FOSTER

Keyword(s):

Vegetable Tanning

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Current trends in leather science

Journal of Leather Science and Engineering ◽

10.1186/s42825-020-00041-0 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Anthony D. Covington ◽

William R. Wise

Keyword(s):

Ionic Liquids ◽

Potential Role ◽

Solid Medium ◽

Leather Industry ◽

Chromium Vi ◽

Current Trends ◽

New Findings ◽

Vegetable Tanning ◽

Sulfide Species

Abstract In preparing the second edition of ‘Tanning Chemistry. The Science of Leather.’, the literature was updated and the content was revised and reviewed. Here, the new findings are presented and discussed. Notable developments include the necessary rethinking of the mechanism of sulfide unhairing because of new understanding of the aqueous chemistry of sulfide species. Revision upwards of the value of the second pKa for sulfide species ionisation means that S2− cannot exist in an aqueous medium, so the unhairing species in hair burn reactions is HS−. Although the technology remains the same, this means the mechanisms of associated reactions such as immunisation must be revised. Rawstock preservation has benefitted from studies of the potential role of materials from plants which accumulate salt, but which also contribute terpene compounds. There is also further discussion on the continuing issue of chromium (VI) in the leather industry. The application to processing of new solvents, ionic liquids and deep eutectics, is the coming technology, which offers transforming options for new chemistries and products. Renewed interest in vegetable tanning and methods of wet white processing are current trends. Also, within the topic of reagent delivery is processing in a solid medium of plastic beads. Graphical abstract

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Cleaner chrome tanning — emerging options

Journal of Cleaner Production ◽

10.1016/s0959-6526(01)00015-4 ◽

2002 ◽

Vol 10 (1) ◽

pp. 69-74 ◽

Cited By ~ 75

Author(s):

V.J Sundar ◽

J Raghava Rao ◽

C Muralidharan

Keyword(s):

Chrome Tanning

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