Annals of the University of Oradea Fascicle of Textiles , Leatherwork 195 New Eco-Efficient Products Used in Leather Industry (original) (raw)
Related papers
Study and Practice on Alternative Eco-Friendly Processes for Leather Manufacture
2010
The inclusion of environmental issues in the definition and implementation of other policies is essential for achieving the objective of sustainable development. Leather industry, which has a considerable pollutant impact, must find efficient technological and economical solutions for this problem. Efficient raw material and energy usage, optimum process chemical utilisation, recovering and recycling of waste and substitution of harmful substances are important principles of the IPPC Directive. For tanneries the focal points are water consumption, efficient use and substitution of potentially harmful process agents and waste reduction within the process in conjunction with the recycling and re-use options. Chromium (III) salts are extensively used in the tanning process; about 90% of the leather manufactured worldwide is tanned using chromium (III). It has been used in the leather industry for almost 150 years, because it remains the most efficient and versatile tanning agent availa...
Waste Management, 2019
One of the long lasting problems associated with leather industry is to meet environmental standards for both liquid and solid wastes. Statistics show that one tonne of wet-salted hides/skins yields around 650 kg of solid waste. Among various wastes generated, trimmings for the most part have been underutilized. Collagen presents in trimmings waste are effectively used but hair goes unutilized or at the most as feed for boilers during gelatin manufacturing. Hence, newer technology is needed for complete and effective utilization of raw trimmings. In leather manufacture, formaldehyde condensates polymers are used as re-tanning agent to enhance the compaction of leather. However, these products are hard for biodegradation and also cause the release of free formaldehyde in leather, which is a known carcinogen. Here, there is a need for development of formaldehyde free re-tanning agent for eco-benign leather processing. In this work an attempt had been made to develop formaldehyde free biodegradable eco-benign retanning agent from raw trimming of tannery solid waste as a circular economy model. Alkaline (7.5% w/w NaOH)-hydrogen peroxide (10%w/w) pre-treatment followed by thermal hydrolysis at 100°C for 5 h was an optimized method for effective hydrolysis of trimmings and the process of preparation of product results in the holistic utilization of raw trimmings. The developed product was characterized using Dynamic light scattering and FTIR techniques. The product prepared was further used in leather manufacture as a re-tanning agent and was found to impart multifunctional properties to leathers such as fullness, grain tightness and shade of dye brilliance. Product improves the mechanical strength characteristics of leather and also the exhaustion of post-tanning chemicals. SEM analysis shows that the experimental leather is more compact and flat than control. This novel strategy had not only solved the issue of solid waste but also resulted in a greener leather auxiliary leading to greener environment.
A potential new commercial method for processing leather to reduce environmental impact
Environmental Science and Pollution Research - International, 2008
Introduction Current leather processing method involves dehairing and fibre opening employing lime and sulphide, which results in higher negative impact on the environment due to its uncleanness. This method of dehairing and fibreopening process accounts for nearly 70-80% biochemical oxygen demand and chemical oxygen demand (COD) in tannery wastewater and also the generation of H 2 S gas. Materials and methods Hence, an attempt has been made to reduce the environmental impact of the leather processing through a biochemical approach, employing proteolytic enzyme and sodium metasilicate for performing the above process more cleanly. Results and discussion The developed process exhibits significant reduction in environmental parametres such as COD and total solid loads by 55% and 25%, respectively. This method completely avoids the formation of lime sludge. Conclusion The functional properties of the leathers are also on par with conventionally processed leathers. Further, the process seems to be commercially viable.
Sustainable products in the leather industry
2020
Protecting the environment is one of the three objectives of sustainability. One way to achieve this is to preserve natural resources by using renewable or residual raw materials. These products have a shorter lifespan and a lower carbon footprint, are highly biodegradable, and are therefore considered to be sustainable products. In this paper, three retanning agents and two oils classified as sustainable products were studied. First, biobased carbon content (an indicator of renewable raw material content) was determined. Then, the physical and organoleptic properties of the leathers treated with each product (degree of softness, firmness and fullness) were evaluated. The COD of residual baths was also determined in oils. The products presented in this paper meet the sustainability requirements, i.e., high renewable raw material content, short lifespan, and low carbon footprint. In addition, these products show high fixation and therefore have a low COD in residual baths, thus also ...
Vitrification: An alternative to minimize environmental impact caused by leather industry wastes
Journal of Hazardous Materials, 2009
The main purpose of this work was the investigation of the immobilization of chromium ion present in the ash from the incineration of chromium-tanned leather shavings (ACS) by means of vitrified ceramic bodies. To achieve the immobilization samples were initially produced adding soda-lime glass to ACS. After that, new formulations were produced with the addition of pure oxides, TiO 2 and MgO, to the sodalime glass and ACS sample. These samples were conformed by pressing and fired in an eletrical furnace, at temperatures of 750, 800, 950 and 1000 • C.
Solid wastes generation in the leather industry and its utilization for cleaner environmentA review
Leather industry, one of the polluting industries because of generation of huge amount of liquid and solid wastes, also emits obnoxious smell because of degradation of proteinous material of skin and generation of gases such as NH 3 , H 2 S and CO 2. Solid wastes are raw trimmings, fleshings, chrome shavings, buffing dusts and keratin wastes. Accumulation of these wastes lead to sludge problem and choking of treatment pipes and finally results in reduction in efficiency of treatment plant. Treatment of solid wastes also is not cost effective, posing economic burden to the tanners. Leather industry in the developing countries is facing lot of solid wastes problem and many tanneries closed for not meeting biochemical oxygen (BOD) demand and total dissolved solids (TDS) norms. The objective of this paper is to review the kinds of solid wastes generated in leather industry and the useful technologies developed to overcome the solid wastes problem.
Trends and advancements in sustainable leather processing: Future directions and challenges—A review
Journal of Environmental Chemical Engineering, 2020
In spite of sustained efforts by researchers, the gap between desired objectives with respect to sustainable leather technologies and achieved levels is still at large. At this juncture, this review presents an array of sustainable greener options addressing all major unit operations of leather making. As an alternative to traditional preservation, phyto-based preservation options for raw skins & hides reducing total dissolved solids and chlorides around 70 % are discussed. Oxidative unhairing reducing biochemical oxygen demand & chemical oxygen demand around 40 % is detailed as an alternate to traditional unhairing that is both harmful and polluting in nature. High-exhaust tanning technologies based on co-polymers increasing uptake to 95 % level are presented. The case of metal-free, organic only glyoxal/ wattle-tanned leathers with enhanced organoleptic properties is discussed. A starch-grafted collagen hydrolysate co-polymer exhausting dye up to 96 % is presented as high-exhaust dyeing system in this paper. Also, laccase-enzyme-based bio-degrading system for recalcitrant post-tanning effluent is furnished. A new method for extracting cellulose derivative from downstream wastes of sugar sector to be used in leather finishing is deliberated. A novel bio-filter based odour abatement system capturing noxious gaseous emissions from tannery environment is showcased as well. In all, this review reflects on the recent sustainable leather technologies that have potential for commercial exploitation in the near future.
Toxic hazards of leather industry and technologies to combat threat: a review
Leather industry has significant economic influence; however, it suffers from the negative impact due to environmental pollution caused by tannery wastes produced during leather processing processes. The tanning processes contribute significantly to chemical oxygen demand (COD), total dissolved solids (TDS), chlorides, sulfates and heavy metal pollution. The chemicals discharged into aquatic systems end up in highly polluted sediments and salinisation of rivers. European Chemical Agency (ECHA) has prioritized some of the hazardous chemicals used in leather under Substances of Very High Concern (SVHC) and substances for Authorization. The situation has highlighted the need for greener technologies. Out of the two broad categories of technical methods, the first group involves the introduction of processing technologies by decreasing the effluent pollution load, avoiding the use of harmful chemicals and producing solid wastes that can be used as by-products. The other category is related to the treatment of wastewater, handling and processing of solid waste in an environment-friendly manner. Both methods have been applied to prevent negative impact on the environment during leather production. The methods have been reviewed for their technical suitability and commercial feasibility and it was felt that combination of both is essential. The technologies can have up-front additional costs but have to be balanced against multiple benefits in terms of environmental cleanup, improved labour productivity, material quality consistency and better international image. By using the best available technologies and optimized systems the leather industry can evolve as an environment friendly technology.
Journal of the Society of Leather Technologists and Chemists
2002
From an environmental standpoint the leather industry is an easy target for the thoughtless or prejudiced observer. With the terminology of corporate social responsibility (CSR) and in particular of carbon footprinting frequently abused and rarely clearly defined it is hard for the impartial observer to get a clear understanding of the scientific facts. This paper looks at carbon footprinting in particular and CSR in general and relates them to the specifics of the leather industry. Based on a study of current literature and knowledge it demonstrates that leather can be proud of its credentials and the attacks made on it in these regards are unfounded.