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UNIDO has prepared and published over one hundred publications, papers, manuals and guidelines, primarily aimed at technical experts and policy makers in developing countries, though many are used by sector-related institutions and development organizations elsewhere.

The website is intended to provide an easy access to information sources on the leather, footwear and leather products industry, as well as to UNIDO publications related to the leather sector in one place, including earlier publications that were previously only available in hard copy.

The paper presents the results of the implementation of solar collectors in three Bangladeshi tanneries as well as of energy audit in four Bangladeshi tanneries to evaluate and improve their electrical performance.

It is well known that tanneries use high amounts of hot water and electricity, and today energy costs are raising very fast all over the world, with energy costs increasing their share in the costs of leather production. Other problem especially in developing countries are frequent power cuts and problems with energy supply. Tannery relocation planned in Bangladesh from Hazaribagh to new Tannery Estate Dhaka is an opportunity to implement measures to reduce energy consumption which should lead to reduced costs for production but also reduced GHG production. Therefore, within the Re-Tie-Bangladesh project (Reduction of Environmental Threats and Increase of Exportability of Bangladeshi Leather Products1) UNIDO has implemented two actions to reduce energy costs in Bangladeshi tanneries: use of solar energy - solar water heating and electrical performance improvement.

In view of ever increasing legal and social pressures, no tanner can afford to be unfamiliar with the main issues and principles of environmental protection pertaining to tannery operations. Among these, preventing pollution and promoting cleaner leather processing, which ultimately leads to lower treatment costs, clearly remain a priority. Through the application of industrially proven low-waste advanced methods - such as using salt-free preserved raw hides and skins, hair-save liming, low-ammonia or ammonia-free deliming and bating, advanced chrome management system, etcetera - it is possible to decrease the pollution load expressed as COD and BOD5 by more than 30%, sulphides by about 60 to 70 %, ammonia nitrogen by 80%, total (Kjeldahl) nitrogen by 50%, chlorides by 70%, sulphates by 65 % and chromium by 90%. Yet, despite all preventive measures, there is still a considerable amount of pollution load to be dealt with by the end-of-pipe methods. The purpose of this booklet is to help a tanner or a tannery manager (possibly a well-trained leather technologist) to get familiarized with basic principles and methods of treatment of tannery effluents. This knowledge should make him better equipped for communications with the factory’s environmental unit, environmental authorities and NGOs. To keep the manual short and concise, there are many simplifications and omissions of details; for in-depth understanding of the complexities of treatment of effluents and solid wastes (sludge) we recommend you to consult extensive literature on this subject. Finally, and contrary to the widespread misperception that vegetable tanning is environmentally harmless (in reality its effluents have very high, difficult-to-treat COD), the manual basically refers to the combined chrome tanning (i.e. chrome tanning supplemented by vegetable and synthetic tanning agents) because it is by far the most prevailing leather tanning method.

Based on available and reliable data the foot measurement survey made in India in 1999 led to a very important conclusion: the proportion (i.e. shape) of feet of the local population differs considerably from what is built in European and North-American shoe lasts. The main reason is the ethnic (anthropologic) difference between European and American people, but the fact that the overwhelming majority of the Indian population wears open type of footwear (sandals, chappels, slippers etc.) or nothing must have its impact as well. Although substantial differences have been identified between geographic regions of the country it is quite apparent that

Indian feet are flatter, i.e. their forepart - especially around the ball and waist part - are wider and lower than in

case of European feet. Indian feet have shorter forepart: the distance of ball points from the heel part is relatively larger than that of European feet. The consequences are that footwear made on European shoe lasts do not really fit on Indian feet (i.e. they are not comfortable) and wear off quickly. Further distinction should be between different regions of the country. All this means that specially designed shoe lasts should be used for footwear produced for domestic sale in India.

In Chennai and Tamil Nadu/India, which was the basis for demonstration of UNIDO regional projects, circumstances at the time of project (mid 90's) commencement were such that the tanning Industry was under considerable pressure vis-à-vis effluent treatment. As a result several tanneries or clusters had already undertaken investments in primary or secondary effluent treatment. Rather than create a possible redundant model plant, the project strategy was oriented towards demonstration of four full scale model effluent treatment plants representing different aspects of tannery effluent treatment plant in terms of influent, treatment process and size. Thus, the Ranitec CETP with treatment capacity of 4,000 m3/d receiving effluent from 76 tanneries processing from raw to finished and using amongst others an anaerobic treatment system (lagoon) was upgraded to serve as a model for similar treatment plants in the region. The Vishtec CETP with a capacity of 3,400 m3/d of effluent using two stage aerobic treatment system was upgraded (mainly process control) to be a second model site. The President Kid Leather Company ETP, 120 m3/d receiving effluent from semi-finished to finished tanning processes from an isolated was upgraded as a model site (automatic dosing, laboratory). The MHT Company ETP, capacity 100 m3/d, receiving effluent from a traditional isolated vegetable tannery, a low cost anaerobic treatment system, was upgraded and serves as a model for similar units.

Detailed reports describing assisted tannery effluent treatment plants:

i) Common Effluent Treatment Plant, Amburtec, Ambur, India

ii) Common Effluent Treatment Plant, Kolkota, Leather Complex Kolkota, India

iii) Effluent Treatment Plant,  Meera Hussain Tannery, Melvsiharam, India

iv) Common Effluent Treatment Plant, Pallavaram, Chennai, India

v) Common Effluent Treatment Plant, Ranitec, Ranipet, India

vi) Common Effluent Treatment Plant, SIDCO, Ranipet, India

vii) Common Effluent Treatment Plant, VISHTEC, Melvisharam, India

This survey prepared and presented during the 17th UNIDO Leather Panel is a follow-up to Worldwide Study of the Leather and Leather Products Industry, which was the outcome of an exhaustive survey carried out by UNIDO in the 1970s. It is intended to assist the Organization in the formulation of future assistance programmes and in detecting areas where further study of various kinds may be useful. This report assesses the worldwide prospects of the leather and leather products industry in the coming decade. It examines the major underlying trends of recent years and how they are expected to evolve in the short to medium term. In its attempt to provide a thorough picture of the leather sector, the report covers its various aspects: the availability of raw material, the tanning industry, and the manufacture of footwear and other leather products. The basic intention is to help discern prevailing trends in global trade and to support efforts to design an effective role for organizations in the industrial development arena. The findings and forecasts published here are meant to be indicative rather than definitive and to form a basis for further surveys and studies. The need to compile this report arose out of the 16th session of the UNIDO Leather and Leather Products Industry Panel held in Brazil in May 2007. The panel recommended that UNIDO undertake a comprehensive study on the future development of the world leather and leather products industry, a study that would cover demand, technology, production, and trade. Consequently, the UNIDO study provides an analysis of the contemporary demand for leather products (footwear, leather goods, gloves, leather garments, sports goods, upholstery, etc.) vis-à-vis the availability of resources (raw hides and skins, manufacturing capacities, skilled labour, knowledge, support industries, and services). It also contains information on other important aspects of the leather industry: trade statistics, the geographic distribution of production, technology developments, physical infrastructure, environmental conditions, and social aspects involved in the production of leather.

Based on new data and requests from interested users, the revised second edition of the paper Pollutants in tannery effluents was prepared drawing on technical inputs by J. Buljan, I. Král, M. Bosnić, R. Daniels. This training material is primarily intended to meet the needs of tanners and people of different profiles associated with environmental protection in the leather industry in developing countries.

The environment is under increasing pressures from solid and liquid wastes as by-products from leather manufacture and tannery effluent create significant pollution unless there has been a form of treatment before discharge.  The industry has gained a negative image in the society with respect to its pollution potential and therefore the leather processing activity is facing a serious challenge.

The paper presents the main sources of pollution and typical pollution loads generated by tanning processes adopted by the tanneries in developing countries, volume(s) of wastewater discharged, the corresponding concentrations of main pollutants as well as the the table of widely prevailing discharge standards.

In this edition the main pollutants' parameters are elaborated in great detail, together with descriptions of their negative environmental impact. Air pollution and toxicity aspects are expanded and a concise chapter on Substances of Very High Concern, SVHC ( carcinogenic, mutagenic, bioaccumulative, persistent etc.) introduced. One can also find photos of equipment used for laboratory analysis.

For the country-wise overview of discharge standards (admittedly somewhat obsolete) please refer to Part II of the first edition.

Chrome tanning is the most common type of tanning in the world. Chrome tanned leathers are characterised by top handling quality, high hydro-thermal stability, user-specific properties and versatile applicability. Waste chrome from leather manufacturing, however, poses a significant disposal problem. Throughout the world, chrome discharge from tanneries is subject to strict regulations. That notwithstanding, chrome is a component that has to be strictly monitored. The environmental impact of chrome discharged from tanneries has been a subject of extensive scientific and technical dispute. Although the legislative limits on the disposal of solid chrome-containing waste have been relaxed in some countries, liquid emissions remain strictly regulated throughout the world. Given the close link between chrome tanning and the environmental impact of leather manufacturing, chrome management is of primary importance in tanning operations. This paper provides information on chrome management and those techniques most frequently used to reduce the amount of chrome in tannery wastewater. By providing information and citing practical experience, the paper aims at contributing to sustainable development of leather manufacture without avoidable harm to environment.

This short paper presented during the 14th UNIDO Leather Panel in Zlin/Czech Republic reports on the general situation, issues and methodology adopted as well as practical experience in implementation of occupational safety and health standards (OSH)  at work in tanneries under UNIDO’s Regional Programme for Pollution Control in the Tanning Industry in South East Asia in late 90-ies involving .international and local experts. For a practical OSH manual see the document Occupational Safety and Health Aspects of Leather Manufacture.

This study is primarily focused on the pollution load discharged in effluents and the scope for decreasing that load. In addition to knowing how to produce and sell high quality leather, tanners must also be familiar with techniques for decreasing the pollution load discharged in effluents from individual processing operations. The study aims at heightening tanners’ awareness of those techniques. It calculates the decreases possible in a well-managed tannery processing bovine hides into chrome tanned leathers and describes how pollution load can be reduced by introducing advanced technologies based on low-waste processing methods that have been proven on an industrial scale will be taken into account. The study does not consider industrially unproven and purely experimental methods.

Conventional treatment of tannery effluents does not affect the TDS content (colloquially: salinity); they remain unsuitable for lifestock watering or irrigation which, especially in arid areas, represents a great loss of natural resource. This paper reports on successful irrigation trials with treated effluent from a CETP servicing a cluster of tanneries processing wet blue and crust leather into finished leather and with TDS not exceeding 5000 mg/l and chlorides not exceeding 900 mg/l. Eventually a plot of barren land was converted into a pleasant park-like area.This paper, based on the project implemented by a women-only team, provides information on saline resistant plants and assess their growth properties; and the impact that the continuous application of treated effluent had on the soil and ground water.