Project Report On Environmental Impact Assessment (in Leather Industry) Submitted To:Prof. Leena Submitted By:Siddharth Singh MBA [Marketing] Date: 11/12/2009
1
INDEX
Sr. No .
Topics
Page No.
1.
EIA Introduction
3
2.
Introduction to Leather Industry
4
3.
Overview of Indian Leather Industry
6
4.
Leather Production Process
9
5.
Residues Generated in Leather Production
12
6.
EIA in Leather Industry
14
7.
Leather Industry & Environmental Issues
17
8.
Envi Enviro ronm nmen enttal Fri Friendl endly y Prod Produc ucttion ion Met Methods hods & Technologies
18
9.
Final Consideration
20
10.
References
21
Environmental Impact Assessment 2
{EIA} Introduction:
An environmental environmental impact assessment (EIA) is an assessment of the possible impact—positive or negative—that a proposed project may have on the environment, together consisting of the natural, social and economic aspects. The purpose of the assessment is to ensure that decision makers consider the ensuing environmental impacts to decide whether to proceed with the project. Environmental Impact Assessment (EIA) is an important management tool tool for for ensu ensuri ring ng op opti tima mall use use of natu natura rall reso resour urce cess for for sust sustai aina nabl blee development. A beginning in this direction was made in our country with the impact assessment of river valley projects in 1978-79 and the scope has subsequently been enhanced to cover other developmental sectors such as indu indust stri ries es,, ther therma mall po powe werr proj projec ects ts,, mini mining ng sche scheme mess etc. etc. To faci facili lita tate te collec collectio tion n of enviro environme nmenta ntall data data and prepar preparati ation on of manage managemen mentt plans, plans, guidelines have been evolved and circulated to the concerned Central and State Government Departments. EIA has now been made mandatory under the Environmental (Protection Act, 1986) for 29 categories of developmental activities involving investments of Rs. 50 crores and above. The Ministry of Environment and Forests of India have been in a great effort in Environmental Impact Assessment in India. The main laws in nation are Water Act(1974), The Indian Wildlife (Protection) Act (1972), The Air (Preve (Preventi ntion on and Contro Controll of Pollut Pollution ion)) Act (1981) (1981) and The Enviro Environme nment nt (Protection) Act (1986). The responsible body for this is Central Pollution Control Board (CPCB). Definition:
The International Association for Impact Assessment (IAIA) defines an envi enviro ronm nmen enta tall impa impact ct asse assess ssme ment nt as “the “the proc proces esss of iden identi tify fyin ing, g, predi predicti cting, ng, evalua evaluatin ting g and mitiga mitigatin ting g the biophysical, biophysical, soci social al,, and and othe other r relevant effects of development proposals prior to major decisions being taken and commitments made.”
Leather Industry 3
Introduction:
Leather industry has been categorized as one of the high hi ghly ly poll pollut utin ing g in indu dust stri ries es and and ther there e are are conc concer erns ns that that leat leather her-m -mak akin ing g acti activi vity ty can can have have adver adverse se impa impact ct on the the environment. The global production of about 24 billion m2 of leather leather by 2009 2009 presen presents ts a consid considerab erable le challen challenge ge to the indu in dust stry ry cons consid ider erin ing g the the harm harmfu full natu nature re of some some of the the chemicals used in leather processing. The tannery effluents are characterized by high contents of dissolved, suspended orga organi nic c and and in inor orga gani nic c sol solid ids s gi givi ving ng rise rise to hi high gh oxyg oxygen en dema demand nd and and pote potent ntia iall lly y toxi toxic c meta metall salt salts s and chrom chromiu ium m metal etal ion. on. The The di dis sagre agreea eabl ble e odor dor eman emanat atiing from from the decomposition of prote oteinous waste materia rial and the presenc presence e of sul sulphi phide, de, ammonia ammonia and other other volati volatile le organi organic c compounds are also associated with tanning activities. Solid wastes generated in leather industries contribute mainly skin trimmings, Keratin wastes, fleshing wastes, chrome shaving wastes and buffing wastes. It constitutes protein as the main component. If these protein and other chemicals, which are prese present nt in the the chem chemic ical al treat treated ed prot protei ein, n, are not not util utiliz ized ed prop properl erly y it will will pose pose hazard hazardous ous poll pollut utio ion n prob proble lem m to the the environment. Raw Raw Mate Materi rial als, s, Chem Chemic ical alss Used Used and and Emis Emissi sion on Fact Factor orss in Le Leat athe herr Industry:
Raw material for leather industry is raw hide or skin. The salt used for preserving the skin/hide discharges huge amount of pollution load in terms of tota totall diss dissol olve ved d soli solids ds (TDS (TDS)) and and chlo chlori ride des. s. Othe Otherr majo majorr po poll llut utin ing g chemicals used in tanning industry are lime, sodium sulphide, ammonium salts, salts, sulphu sulphuric ric acid, acid, chromi chromium um salts salts and vegeta vegetable ble tannin tanning g materi materials als.. Currently, about 6.5 million tons of wet salted hides and skins are processed worldwide annually. About 3.5 million tons of various chemicals are used for leather processing. A considerable part of this amount is discharged into the effluent. At an average consumption of 45-50 m 3 of the waste liquor and 800 kg of solid wastes per ton of raw hide are discharged by the leather industry. The composition of liquid and solid wastes generated in tanneries worldwide are: COD, 1470; BOD, 619; suspended solids, 920; chromium,
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30; sulphur, 60; and solid wastes (trimmings, fleshing, shaving & buffing dust), 3000 thousand tons.
Soaking
Liming
De Deliming
Pickling
Chrome Tanning
Dyeing & Fatliquoring
Composite (incl. Washing)
BOD
8.3-18.8
17.5-35.0
1.5-4.5
0.3-0.5
0.5-1.2
1.5-3.0
35.0-105.0
COD
22.5-45.0
35.0-87.5
3.8-10.5
0.8-2.3
1.5-3.8
3.8-10.5
87.5-280.0
262.5-415.5
6.0-15.0
26.3-52.6
45.0-90.0
6.0-15.0
528.0-875.0
22.5-52.5
105.0175.0 21.0-70.0
2.3-6.0
0.8-2.3
1.5-3.8
0.9-1.5
70.0-140.0
112.5-225.0
14.0-28.0
1.5-3.0
1.5-3.8
23.0-38.0
0.8-1.5
210.0-332.5
-
-
-
-
3.0 - 7.5
-
3.5-8.8
Total Solids Solids suspended Soli Solids ds as Cl-
chlo chlori ride dess
Chromium (total) as Cr
(All values expressed in kg/tonne of hide processed) Table: - Typical waste emission factors associated with leather processing (Source: Journal of Scientific & Industrial Research, July 2009)
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Indian Leather Industry Indian leather industry plays an important role both as an earner of foreign exchange and provider of employment. The industry, which employs more than 2.5 million people, exported about US$ 1970.98 million worth of goods in 2000-01. A large proportion of India’s export of leather and leather pro produ duct ctss is to four four coun countr trie ies, s, name namely ly USA, USA, Germ German any, y, UK and and Ital Italy. y. Together, these countries accounted for 59% of the total exports of these products during 2000-01. Other major importers of Indian leather products include: Spain, Hong Kong and France. For a number of years the leather sector was reserved for small-scale sector in India. This was done done primarily to promote promote employment. employment. A number of policy policy instru instrumen ments ts such such as tax exempt exemption ion,, licens licensing ing restri restricti ctions ons and reservation policy were used to encourage the growth of the leather industry in the small scale and cottage industry sector. An important implication of the government’s policy to reserve the leather industry for the small scale sector in the past has been a slow pace of modernization. Most of the tanneries lacked technical and financial resources to introduce modern technology. As a result, the leather industry, by and large, large, uses uses obsole obsolete te and ineffi inefficie cient nt techno technolog logies ies,, and its envir environm onment ental al performance is poor. The go The gove vern rnme ment nt has has intr introd oduc uced ed a nu numb mber er of po poli licy cy chan change gess to promote technological up-gradation of the industry. Firstly, the government partly removed the barrier to entry and permitted large firms to enter the industry. Large firms are now permitted to enter the sector, provided that they export a minimum of 95% of their production of finished leather. The government also permits the import of modern technology, machines and chemic chemicals als.. It has also also initia initiated ted scheme schemess to provid providee financ financial ial suppor supportt to promote the modernization of tanneries. During the 1970s, India export consisted largely of raw hides and skins. skins. In later later years, years, the gov govern ernmen mentt introd introduce uced d polici policies es to promot promotee the 6
export of higher value added products. For example, it banned the export of raw hides and skins and introduced quotas on the export of semi-finished leather. It also provided several incentives for export of finished products. As a result result,, India India’s ’s leather leather export export basket basket has seen import important ant change. change. The proportion of leather products has seen a sharp increase since the early 1980s. Presently, more than 80% of India’s exports (by value) consist of finished products. As a resu result lt of thes thesee chan change ges, s, the the stru struct ctur uree of the the indu indust stry ry has has undergone a major change. Although a majority of firms are still small, a high proportion of good quality leather is now produced by a number of large firms. These firms are particularly important as exporters: about 35 larg largee firm firmss are are repo report rted ed to acco accoun untt for for 60 60% % of Indi India’ a’ss leat leathe herr expo export rt.. Furthermore, an increasing proportion of India’s leather exports consist of finished goods. India has about 3,000 tanneries with a total processing capacity of 700,000 tons of hides and skins per year. More than 90% of the tanneries are small or medium sized, with processing capacities of less than 2-3 tons of hides/ hides/ski skins ns per day. day. India Indian n tanner tanneries ies proce process ss sheep, sheep, goatsk goatskin, in, cow and buf buffa falo lo hide hides, s, usin using g bo both th vege vegeta tabl blee and and chro chrome me tann tannin ing. g. As leat leathe her r processing requires large amounts of water, most of the tanneries are located near the riverbank. The highest concentration of tanneries in India in India is on the banks of the Ganga river system in North India and the Palar river system in Tamil Nadu. Technology Status of India’s Leather Industry
Most tann Most tanner erie iess in Indi Indiaa use use old old and and inef ineffi fici cien entt tech techno nolo logi gies es and and production methods. Even in large tanneries the general level of technology is low. low. The use of ineffi inefficie cient nt techno technolog logy y is largel largely y respon responsib sible le for the wasteful use of water and chemicals, high load of effluent pollutants and low productivity of the tanning industry. A study of India’s tanning industry, carried out on behalf of India’s Ministry of Science and Technology, brings out these facts clearly. According to this study: 1. The raw hides hides and skins skins are salt salt preserved preserved in India. India. This This causes causes a serious problem of excess of salt in tannery effluent. 2. Th Thee yie yield of leath eather er fro from wet sal salted ted sto stock is lower ower in India dia than than international norms. This is partly due to higher level of process waste. 7
3. The chemical chemical consump consumption tion in Indian Indian tanneries tanneries is about about 25 to 30% higher higher than international norms. This is due to the use of inefficient equipment and processes and the absence of recycling. 4. The specific specific water water consumptio consumption n in Indian Indian tanneries tanneries is more more than double double that that of tanneri tanneries es in develo developed ped countri countries. es. The tanning tanning units units in India India consume an average of 40 liter/sq ft of finished leather. Compared to this, the tanneries in developed countries consume about 12-15 liters/sq ft. 5. A majorit majority y of the tanner tanneries ies in India India are very old and their their layout layout is not efficient. This leads to bottlenecks for process and material handling, multidirectional material flow and excessive material handling. Most of these tanneries also have very unhygienic working conditions, inadequate ventilation and lighting.
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LEATHER PRODUCTION PROCESS The leather manufacturing process is divided into three fundamental sub-processes: Preparatory stages Tanning Crusting
All true true leathe leathers rs will will und underg ergo o these these sub-p sub-proc rocess esses. es. A furthe furtherr subsub process, process, surface coating can be added added into the leather leather process process sequence sequence but not all leathers receive surface treatment. Since many types of leather exist, it is difficult to create a list of operations that all leathers must undergo. 1) Preparatory stages:
The preparatory stages are when the hide/skin is prepared for tanning. Preparato Preparatory ry stages stages may include: include: preserva preservation, tion, soaking, soaking, liming, liming, unhairing, unhairing, fleshing, splitting, splitting, reli relimi ming ng,, deliming, deliming, bating, bating, degreasing, degreasing, friz frizzi zing ng,, bleaching, bleaching, pickling and depickling. 2)
Tanning:
Tanning is the process which converts the protein of the raw hide or skin into a stable material which will not putrefy and is suitable for a wide variety of end applications. The principal difference between raw hides and tanned hides is that raw hides dry out to form a hard inflexible material that when re-wetted (or wetted back) putrefy, while tanned material dries out to a flexible form that does not become putrid when wetted back. There is a large number of different tanning methods and materials that can be used, the choice is ultimately dependent on the end application of the leather. The most commonly used tanning material is chromium, chromium , which leaves the leather once on ce tann tanned ed a pale pale blue blue colo colorr (due (due to the the chro chromi mium um), ), this this prod produc uctt is commonly called “wet blue”. The hides once they have finished pickling will typically be between pH between pH of 2.8-3.2. At this point the hides would be loaded in a drum and immersed in a float containing the tanning liquor. The hides 9
are allowed to soak (while the drum slowly rotates about its axle) axle) and the tannin tanning g liquor liquor slowly slowly penetr penetrate atess throug through h the full full substa substance nce of the hide. hide. Regular checks will be made to see the penetration by cutting the crosssection of a hide and observing the degree of penetration. Once a good even degree of penetration exists, the pH of the float is slowly raised in a process called basification. This basification process fixes the tanning material to the leather and the more tanning material fixed the higher the hydrothermal stability and increased shrinkage temperature resistance of the leather. The pH of the leather when chrome tanned would typically finish somewhere between 3.8-4.2.
3)
Crusting:
Crusting is when the hide/skin is thinned, retanned and lubricated. Often, Often, a colori coloring ng operat operation ion is includ included ed in the the crusti crusting ng sub-pr sub-proce ocess. ss. The chemicals added during crusting have to be fixed in place. The culmination of the crusting sub-process is the drying and softening operations. Crusting may include the following operations: wetting back , sammying, splitting, shaving, rechroming, neutralization, neutralization, retanning, dyeing, dyeing, fatliquoring, filling, stuffing, stripping, whitening, whitening, fixating, setting, drying, conditioning, milling, milling, staking, and buffing. For some leathers a surface coating is applied. Tanners refer to this as finish finishing ing.. Finish Finishing ing operat operation ionss may inclu include: de: oiling oiling,, brushi brushing, ng, paddin padding, g, impregnation, buffing, spraying, roller coating, curtain coating, coating, polishing, polishing, plating, plating, embossing, embossing, ironing, ironing, ironin ironing/c g/comb ombing ing (for (for hair-o hair-on) n),, glazing and tumbling. tumbling.
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Figure Figuress below below show show the comple complete te leathe leatherr manufa manufactu cturin ring g proces process, s, highlighting the main waste generation points.
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RESIDUE GENERATED IN LEATHER PRODUCTION Solid residue is defined as any solid material that stems from the daily activities of humans in society and which the producer or owner does not consider to have enough importance to be preserved. Liqui Liquid d effl efflue uent nts, s, soli solid d resi residu dues es and and atmo atmosp sphe heri ricc emis emissi sion onss are are genera generated ted in leathe leatherr produc productio tion. n. Organi Organicc and inorga inorganic nic compou compounds nds are present in these pollutants. The organic compounds consist of proteic and lipid components from the animal hides that lose about 30% of organic matter during processing, according to studies. The inorganic compounds are from chemical products that were not completely affixed to the skins during processing. Liquid effluents
The liquid wastes generated by the preparation for tanning operation consist of heavily alkaline and whitish water (excess lime) and contain suet, 12
hairs, muscle tissue, fat and suspended blood. There T here are salts (such as sulfite, sulfate, chloride, sodium, calcium, ammonia), proteins and diverse amino acids acids in soluti solution. on. These These efflue effluents nts have have high high concen concentra tratio tions ns of solids solids in suspension, dissolved proteins and acidic pH. This is the phase with the highest concentration of pollutant and toxic loads in tanning effluents. In order to have an idea of the potential environmental impact, consider that the aver averag agee weig weight ht of 23 Kg/s Kg/sal alte ted d hide hide8 8 and and an aver averag agee orga organi nicc load load of domestic sewage of 54 Kg DBO9/inhabitant/day is the polluting potential of a biodegradable organic load of a tannery that processes 3000 hides/day, equivalent to a population of 85,600 inhabitants. The impact is thus quite significant. The liquid liquid efflue effluents nts genera generated ted by pickli pickling ng and tannin tanning g operat operation ionss mainly contain salt, mineral acids, organic acids, chrome, proteins and some fungicides, with acidic pH and they may contain high concentrations of DQO and and DBO, DBO, depe depend ndin ing g on the the tann tannin ing g agen agentt used used.. Mine Minera rall tann tannin ing g with with chrome is still the main tanning process used in the world, because it is a relatively short process, cheaper and efficient for industrial scale operations. It also gives the leather high quality and resistance, resistance, allowing it to be stored for long periods without risk of rotting, despite its countless impacts in the environment. Atmospheric emissions
Besi Beside dess the the liqu liquid id effl efflue uent nts, s, atmo atmosp sphe heri ricc emis emissi sion onss that that caus causee unpl un plea easa sant nt od odor orss are are also also gene genera rate ted d by the the tann tanner erie iess from from its its vari variou ouss operations. These are gases and vapors, released over the production process and during effluent treatment operations. The main emissions are ammonia (whi (whicch com comes from rom the the part artial ial dec decompo ompossitio ition n of hid hide prot rotein eins), s), hydrosulphuric gas, emissions of volatile compounds from organic solvents, suspended water particles called aerosols and solid particulate material. Solid waste
Solid wastes are the most generated. They can be grouped into two categories:
Non-tanning solid waste: from the rawhide and fleshing and splitting, these are the chippings, flesh, and other wastes resulting from the preparation for tanning process. These wastes are classified as non-
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hazardous hazardous and are rich in collagen collagen and fats. They can be transformed transformed into glue, gelatin, and gum, among others.
Tanning solid waste: these are from the effluent treatment station (chromecontaminated sludge), from the wet finishing phase, when the leat leathe herr go goes es thro throug ugh h the the ph phys ysic ical al-m -mec echa hani nica call ph phas ases es of rest restin ing, g, leveling and cutting (comprised of: burrs, chromed shavings, chaffing, scrapings and chippings of tanned leather) and buffing dust. These wastes are classified as hazardous materials (class 1 wastes) and are rich in trivalent and hexavalent chrome (which can cause cancer and mutations in humans). For each piece of tanned leather, 2 to 3 kg of chromed shavings is generated.
It is thus possible possible to see the great waste generatio generation n by the sector, sector, and waste that can result in expressive environmental impacts. It is fundamental for the sector to invest in specific cares and treatments in the search to minimize these impacts on the environment. That’s why it is so important to implement effective waste management systems, or even to prevent such waste.
ENVIRONMENTAL IMPACT ASSESSMENT IN LEATHER INDUSTRY A tannery’s production process has countless environmental impacts and consumes a large amount of natural resources. The main The main envi enviro ronm nmen enta tall impa impact ctss are: are: od odor or – disc discom omfo fort rt for for the the public's well-being, harmful to water body quality, eventual contamination of the soil and underground waters. These impacts can occur at every phase of the production process and they follow the emission forms and environmental aspects that can cause such impacts:
Conservation and storage of hides: contamination of the air as a result result of releas releasing ing ammoni ammoniaa gas, gas, volati volatile le organi organicc compou compounds nds and hydrosulphuric gas; water contamination by spilling liquids released
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by the skins; soil contamination through pieces of hide and salt with organic matter.
Preparation for tanning operation: contamination of the air with ammonia gas, hydrosulphuric gas and volatile organic compounds; water contamination from residual baths for hide treatment and water from intermediate washings containing organic loads and chemical products (sulfite, diverse salts and others); contamination of the soil from from flesh, flesh, hairs, hairs, hide hide chippi chippings ngs and scrapi scrapings ngs,, with with and withou withoutt chemical products. Tanning process: water contamination from residual hide tanning baths, containing organic loads and chemical products such as chrome, tannin, diverse salts, among others. Finishing process: contamination of the air through the release of volatile organic compounds from solvents in products used; water contam contamina inatio tion n from from residu residual al leathe leatherr treatm treatment ent baths, baths, contai containin ning g organic loads and chemical products (such as chrome, tannin, dyes, oils oils and and othe others rs); ); cont contam amin inat atio ion n of the the soil soil du duee to inap inappr prop opri riat atee dispos disposal al of dust, dust, chaff chaffing ing,, chrome chromed d shavin shavings, gs, semi-f semi-fini inishe shed d and fini finish shed ed tann tanned ed leat leathe herr cutt cuttin ing, g, fini finish shin ing g prod produc uctt wast wastes es,, whic which h include dyes, resins, among others.
With regard to the consumption of inputs and natural resources:
The leather production process consumes nearly 30 to 80m³ of water per ton of processed hide; however, this volume can vary as a result of the differ different ent raw materi materials als,, proces processes ses,, operat operation ional al pract practice icess and management. The average consumption of water for processed salted hide is 630 liters. Thus, a tannery that processes 3000 salted hides per day, consumes approximately 1900 m³, which is equivalent to the daily consumption of a population of nearly 10,500 inhabitants with an average consumption of 180 liters of water/inhabitant per day. This reveals a significant impact in the region’s water source consumption. The consumption of electric energy also depends on the capacity and quantity of consumption, type and state of equipment, type of effluent treatment treatment,, efficient efficient energy energy practices. practices. Consumptio Consumption n varies varies between between 2600 and 11,700 kW/h per ton of salted hide. 15
A large number of chemical products are used, such as surfactants, solvents, solvents, fungicide fungicides, s, insectici insecticides, des, acids, acids, natural natural or synthetic synthetic tannin agents, chrome, titanium, magnesium, dyes, salts, sulfonated oils, etc.
The wastes generated by tanneries are rich in trivalent and hexavalent chrome and their disposal is viewed as toxic by environmental legislation. Triv Trival alen entt chro chrome me is esse essent ntia iall from from a nu nutr trit itio iona nall po poin intt of view view,, and and if absorbed in small quantities by the organism, it is not toxic. Hexavalent chro chrome me is high highly ly toxi toxicc and and has has a cumu cumula lati tive ve effe effect ct on the the orga organi nism sm,, especially the body's soft tissues, such as the liver, kidneys, breasts, prostate, uterus, respiratory system, heart, among others. Wast Wastes es that that cont contai ain n chro chrome me caus causee sign signif ific ican antt impa impact ctss on the the environment due to their high power of contamination. Chrome reaches the water table, rivers and reservoirs that supply the cities. Waste inappropriately disposed of in the soil favors chrome's permanence, which can be absorbed by the plants that will serve as food for humans, thus contaminating the human being. Leather industry employees are the most jeopardized because they live with chrome daily, as well as with other toxic compounds. Most of them suffer from skin allergies and have allergic rhinitis, according to Elizabeth Nascimento, professor of toxicology at the University of São Paulo (USP) College of Pharmaceutical Sciences. Prolonged stays in environments where chrome is used favors the development of lung cancer through the inhalation of large quantities of the substance. As with every heavy metal, chrome accumulates in the organism due to direct contact or the consumption of contaminated water and foods, and over the years, it can cause organ failure, such as kidneys, and eventually death. When inhaled in large doses, its hexavalent form, which is rarer and more hazardous, causes perforations in the nasal septum. The problem is that the cleaning produces another waste, chrome sludge, which must be sent to an appropriate landfill. But, these wastes are ofte often n du dump mped ed in rive rivers rs,, caus causin ing g enor enormo mous us envi enviro ronm nmen enta tall harm harm.. Th Thee inhabitants complain about the rotten egg odor from the hydrosulphuric gas, which can be lethal in high concentrations. It enters the homes through the sewe sewers rs,, whic which h use use the the same same syst system em to coll collec ectt the the effl efflue uent ntss from from the the processing industries. The contamination brought by solid wastes is more 16
subtle. Their effects cannot be seen, but they just as or more serious than those caused by liquid effluent pollution. Contro Controll of atmosp atmospher heric ic emissi emissions ons is anothe anotherr import important ant indust industria riall pr prob obllem that that must ust be solv olved by the sec sector tor due to, in som some cases ases,, occupational illness problems, depending on the tannery’s installations and operational procedures, as well as the discomfort caused to the population in the surrounding area, since they are perceived beyond the industrial limits.
THE LEATHER INDUSTRY AND THE ENVIRONMENTAL ISSUE Client demands in relation to the preservation of the environment have also also reac reache hed d the the leat leathe herr indu indust stri ries es,, whic which h have have grea greatt impa impact ctss on the the environment. New technologies are thus being developed to minimize the results of the impacts from the leather production process. One alternative that has been growing in the sector is tanning without the the use use of chro chrome me.. Th This is chro chrome me-f -fre reee proc proces esss can can beco become me an exce excell llen entt business opportunity and it will be the future way to tan leathers. As an example, we can cite a footwear company located in Northampton shire, England, specialized in footwear for babies that does not use chrome in leat leathe herr tann tannin ing. g. Acco Accord rdin ing g to the the comp compan any, y, the the use use foot footwe wear ar with with conventional leather can cause irritation and dermatitis on babies’ feet. The chrome in the leather can also be ingested if the babies put the shoes in their mouths. The leather used by the company is tanned using vegetal extracts that have less impact on the environment and are biodegradable. 17
Another foreign company that is investing in the chrome-free process is Ecopell, located in Germany. The tanning process used by the industry employs plants and ingredients that do not harm the environment. According to the Law of Conservation of Mass (BRAGA et al., 2002), waste generation is inherent to the transformation process of raw materials into products; however, with the adoption of good pollution free tools the quantity of waste can be minimized and its physical-chemical characteristics altered, causing less impact on the environment. The large amount of waste genera generated ted by the leathe leatherr and footw footwear ear indust industrie riess theref therefore ore consti constitut tutes es a management problem that needs an urgent solution for the environment to not suffer further degradation.
Environmental friendly production methods and technologies The quantity of pollution load generated by the leather industry can be reduced by: Process modification to reduce the generation of waste and pollutants in the beam house; Reuse of chemicals (mainly sulphides and chrome) and spent liqours. Economical use and reuse of water; •
• •
The modifi modificat cation ionss requi required red to make make variou variouss proces processes ses in leathe leather r making environmentally friendly are described below. a) Desalting Desalting and soakin soaking. g. The salt load in the the effluent effluent can be reduced reduced by: Decreasing the amount of salt used to preserve hides by adding environmentally acceptable acceptable anti-septics such as boric acid and sodium sulp sulphi hide de.. It must, must, ho howe weve ver, r, be ment mentio ione ned d that that the use use of these these preservatives reduces shelf life. •
18
Use of improved methods of desalting by using Dodeca frames and desalting machies. Processesing fresh (green) hides, which have been preserved by chilling. •
•
b) Unharing and liming. The pollutants pollutants from these processes processes can be reduced by using the following technologies: Recycl Recycling ing spent spent float. float. This This also leads leads to a reductio reduction n in the amount of water consumption. Enzymatic unharing. This can lead to a reduction in the use of sulphide, leading to a reduction of COD by 30-40%. c) Deliming Deliming and Bating. Bating. The environmen environmentally tally friendly friendly alternati alternatives ves include: include: ammonia free delimng and bathis and carbon dioxide deliming. d) Chrome Chrome tanning tanning.. Cleane Cleanerr techno technolog logies ies to reduce reduce chrome chrome conten contentt in the effluent are: High High exha exhaus usti tion on proc proces esss in whic which h shor shortt floa floats ts at high higher er temperature and pH are used. The process increases the extent of chrome exhaustion and reduces the chrome content in the effluent. Recovery/recycling of chrome. In this process, chrome in the effluent is recovered and reused in tanning process. Low or no chrome tanning. e) Post Tanning. Tanning. The The methods methods to reduce reduce the load of pollutan pollutants ts generated generated by these processes are: High Exhaustion Chrome fixing in neutralization Chrome precipitation. Replacing nitrogenous compounds with other filling agents; Phasing Phasing out environm environmental entally ly hazardous hazardous chemicals chemicals with high COD and BOD values, and limited biodegradability. •
•
•
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FINAL CONSIDERATIONS CONSIDERATIONS Some considerations can be made from this study. The leather sector is very expressive in the national manufacturing universe. The production of leather implies the large consumption of natural resources, especially water, and significant impacts on the environment, since large quantities of solid waste, liquid effluents and atmospheric emissions are generated. If these are not duly treated and appropriated disposed they can harm human health and water sources as well as contaminate the soil. The Indian leather industry is lacking in techniques that increase the qualit quality y of the leathe leatherr produc produced. ed. By achiev achieving ing this this leathe leatherr qualit quality, y, it is possi possible ble to increa increase se the countr country’ y’ss compet competiti itiven veness ess and also also reduc reducee the environmental impacts since wastes would also be reduced. Thus, sector growth requires investments in quality, techniques to minimize or eliminate the the impa impact ctss on the the envi enviro ronm nmen entt and and stud studie iess that that cont contri ribu bute te towa toward rdss 20
mini minimi mizi zing ng sect sector or prob proble lems ms and and towa toward rdss gene genera rati ting ng jobs jobs and and fore foreig ign n reserves, thus contributing towards the country's growth.
References:
“Tanners to pay Compensation”, Leather , June 2001, p. 2. DSIR DSIR,, “Tec “Techn hnol olog ogy y Ev Eval alua uati tion on and and Norm Normss Stud Study y in Leat Leathe her r Tanneries”, Dep Depar artm tmen entt of Scie Scient ntif ific ic and and Indu Indust stri rial al Rese Resear arch ch, Ministry of Science and Technology, New Delhi, November 2008. Kennedy Lorraine, “Cooperating for Survival: tannery Pollution and Joint Action in the palar Valley (India)”, World Development, Vol. 27, No. 9, pp. 1673-169. Ludvik Ludv ik J., J., “The “The Scop Scopee of Decr Decrea easi sing ng Poll Pollut utio ion n Lo Load ad in Leat Leathe her r processing”, United Nations Industrial Development Organization, 9 August 2006.
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Shanmugam Kavitha, “Polluting Leather Units face Closure Threat”, Business Standrard, April 28, 2002. http://www.brazilianleather.com.br http://www.euroleather.com www.indianleatherportal.com kanpurbds.fibre2fashion.com/indian kanpurbds.fibre2fashion.com/indian-leather-ind.asp -leather-ind.asp dipp.nic.in/industry/leather weblis.unep.org www.fao.org
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