Project based on Leather industry their effects on environment and their waste management.

1. Leather Tanning Industry And
Waste Management

2.  Leather Tanning is the process of converting raw hides or skin into leathers
and on further treatment they are converted into leather products.
 The word Tanning is derived from ‘Tannin’ which is an acidic chemical
compound.
 People have been attracted towards various products of leather and hence
they play a major role in modern life.
 Many products like shoes, belt, wallet, hand bags etc of different types are
available in the market.
 Usage of leather products is increased has the population has increased , the
manufacture of products at initial stages were low, but now it’s been
reaching the peek value of extent.

3.  As production increased , the waste from the leather tanning industry is also
increased.
 Leather tanning industry has many effects of environment.
 The raw material of tanning industry is skin, which are extracted from the
animals. From this the animals have been killed and many are affected.
 There are ways to treatment of waste from the leather tanning industry , one
such is Common Effluent Treatment Plant (CETP). In which the harmness
of the waste can be reduced.
 The place where the waste is dumped plays a very important role , that
should not affect the habitat of environment.
 If they are not treated and released in the environment , they cause problems
to habitat of animals and serious health problems humans , ultimately the
environment is affected.

4.  In this project we are going to discuss about the processing of leather in
tanning industry and the waste generated from each stage of processing.
 Leather tanning industry is one of the most polluting industry all over the
world due to enormous amount of solid and liquid waste generated from them.
 Hides and skin have the ability to absorb tannic acid and other chemical
compound that prevent them from decaying, make them resistant to wetting
and keep them supple and durable.
 The tanning industry produces foul smell due to nutritious material present in
skin with evolution of gases like ammonia , hydrogen-sulphate ,carbon-di-
oxide.
 The manufacturing of animal product for human consumption leads inevitably
to the production of waste.

5.  Nature is able to cope up with certain amount of waste via natural
mechanism , however if the concentration of waste is increased , natural
mechanism become overburdened and pollution problem start to occur.
 Due to tanning industry there comes Air , Water , Land pollution due to the
dumping of waste without treating .
 So in order to protect the environment from polluting ,the usage of leather
products must be reduced and the waste must be treated effectively . Should
find an alternative solution for leather products.
 The implementation of waste water and air treatment system , leather
tanners can become more environmentally friendly.
“REDUCE, REUSE, RECYCLE”

6.  The word “Tanning” means the process by collagen fibres in a skin reacts
with chemical agents such as Tannin, alum or other chemicals. Hides and
skin have the capacity to absorb tannic acid and other chemical substances
which prevent them from decaying and make them damp resistant to wet
and keep them supple and durable.
 Only 150 kg of raw material is converted into fine leather out of 1000 kg of
raw material , i.e. There is a waste of 850 kg.
 Fleshing (56%-60%)
 Chrome shaving, chrome splits , buffing dust (35%-40%)
 Skin trimming (5%-7%)
 Hair (2%-5%)
 Over 80% of the organic pollution load in biological oxygen demand (BOD)
that flows from the pre-tanning process many of these waste comes from
degradable hide, skin and hair matters.

7.  Tanning process at least requires 300 kg of chemicals which are added per
tons of hides. Then Non-Used chemical salts appear in waste water. Due to
the change of PH these compound can form precipitate and contribute to a
large amount of solid waste and suspended solids. In an every process of
leather tanning there comes a waste water exception of finishing operation.
In an average 35m^3 of waste water are produced per tons of raw material.
The waste contains high concentration of salts such as ammonia, chromium
, dye and other chemical solvent.
 A huge amount of waste produced by tanning industry is discharged directly
or indirectly in natural water bodies without any treatment. The
underground water system in developing countries such as India or
Bangladesh is polluted with an high degree which is unsuitable for public
use.
 During summer the rate of decomposition of the waste is higher , air
pollution is caused in residential areas by producing intolerable obnoxious.
The industry waste water usually find their way into surface were toxins are
carried down streams and thus pollute water which are used for commercial
use.

8.  Chromium waste enters into the soil and contaminate grounds water system
which provide drinking water for near by communities. Contamination of
waste water which also effects the aquatic life which are common source of
food. Thus aquatic food chain gets affected and the eco-system get
collapsed .( SALMAN ZAFAR , JAN,2007 ) .
 Kanpur, India, stands as a prime example of how tannery chemicals and
wastewater can negatively affect health and ecosystems. In 2013, the city
became the largest exporter of leather. About 80% of the wastewater is
untreated and dumped straight into Kanpur's main water source, the River
Ganges. Farmland is swamped with blue-tinted water, poisoned with
chromium III, lead, and arsenic. Decades of contamination in the air, water,
and soil have caused a variety of diseases in the people who live in the area.
Health problems include asthma, eyesight problems, and skin discoloration.
Chromium is not solely responsible for these diseases. Methyl
isothiazolinone , which is used for microbiological protection (fungal or
bacterial growth), causes problems with the eyes and skin. Anthracen ,
which is used as a leather tanning agent, can cause problems in the kidneys
and liver and is also considered a carcinogen.

9. Formaldehyde and arsenic, which are used for leather finishing, cause health
problems in the eyes, lungs, liver, kidneys, skin, and lymphatic system and are
also considered carcinogens.(Wikipedia)
The export prospects of Indian leather industry firms are influenced by the
major external factors such as quality standard, stiff foreign competitions and
environmental regulation. The environmental regulation becomes more
significant non-tariff barrier among the others. But the question is if the
domestic firm will accept such an environmental compliance in this age of
many competitions, that will depend upon certain issues. The non-compliance
threat perceived by the firm is indicated by the firm’s decision to comply with
the regulations. The decision of how to respond to environmental regulation is
based on the consideration of the potential economic advantage or
disadvantages of not complying or complying. The firm will comply the
economic sanctions that are associated with non-compliance is more than the
cost of compliance of the firm.

10. The regulators are supposed to have the administrative capacity to enforce
regulations. The risk of being caught in non-compliance should be included in the
measurement of the cost of non-complying. In a Bertrand duopoly and in the
presence of consumers who are environmentally aware, the clean up levels that are
chosen by the firms are strategic complements, that is, if two firms A and B exist,
firm A increases its clean up, then naturally consumers would choose firm A and
not firm B. As a result, it would enhance the profit earned by firm A when
compared to firm B. And to get back the marginal, firm B will increase its clean up
level.
CONFLICTED MOTIVATION OF SOCIETY :
To push for border compliance ,the government faces too many conflicting
problems in the developing countries . Due to global training and free trade the
government raises its production value and thus fails to comprimise the
competitiveness of domestic firms. And hence the developing countries are quite
hesistant in keeping up the environmental norms.

11. FRAGMENTED CAPACITY :
The environmental norms is being disturbed due to the political weekness which
hinders the environmental agency. In developing countries, the sectors that are under
the control of small firms, which makes enforcement which makes even more
unsustainable especially for the cash implementation. The small and tiny producers
dominates the leather industry. Because of this the finance is major constraint to
follow the norms. For the environmental complience, the share is 2.05%FOB and
leather is 3.5% export value of FOB. Due to the failure of complaints, these
pollution control measures have been found to be inadequate and hence resulted to
the closure of small tanneries Literature helps us to discuss on a wider range
regarding compliance cost and export competitiveness. Most of the existing
literature focuses on ‘pollution haven’, while little part of the literature is found to
throw light on small firms in the developing countries that cope with stringent
global standard. The literature portrays few factors like High cost of compliance,
Conflicted Motivations of State and Fragmented Capacity of Environmental
Institutions that makes it difficult to comply with environmental standards without
compromising their competitiveness.

12. High Cost of Compliance : The competitive edge of the firms in global market
can be reduced to some extent due to the economic costs imposed due to
certain mandatory regulations. Literature expresses its concern for the firms and
the policy makers in the developing countries by arguing on imposition of
external standards impede trade

13. Industrial Visit
Learning the process of leather in tanning industry
Learning Waste generated from the tanning industry from each stage of
process.
Knowing the effective way for the treatment of waste.
Effects of leather tanning industry.
Waste minimization.
Value addition for leather.
Safe, Healthy Environment in Tannery.
Survey based on project.
Skill development and training.

14. PROCESSING OF LEATHER

15. o Sodium Chloride (NaCl)
o 10% Sodium Liquor
o 4% Lime (CaO)
o 5% Ammonium Sulphate [(NH4)2SO4] or Ammonium Chloride (NH4Cl)
o 1.2% Bi-Sulphate (NaHSo4)
o 1.8% Bat-Barium-Telluride (BaTe)
o Phenolphthalein Indicator
o 0.1% of Ammonium Sulphate [(NH4)2So4]
o 1% Dilute Sulphuric Acid (H2So4)
o 4% Basic Chromium-Sulphate (BCS)
o 1% Sodium Bicarbonate (NaHCo3)
o 1% Formate

16.  The stages involved in the production of leather between curing and tanning are
commonly referred as beam house operation.
 Stages Involved are :- Skinning, Curing, Beam house operation, chrome tanning.
 Skinning: Collection of skin from farm or slaughter house and processing them.
 Curing: Preparing hides begins by curing them with salts. Curing helps the skin
from decaying. It removes water from the hides and skin using a difference in
osmotic pressure. The moisture content is greatly reduced and osmotic pressure is
increased.
 The chromium complexes should be small enough to fit in between the fibres and
the residues of the collagen.
 Penetration level of Beam house operation: They include Order, Skinning, Liming,
Removal of extraneous tissue such as hair, De-liming, Bating, Drenching, Pickling.
 Chrome Tanning: Usually Chromium(III) Sulphate is used . Chromium(III)
compounds are less toxic than Hexa-valent compound.
 The PH must be acidic
 When Chromium is introduced chromium is achieved, again the PH level is raised to
continue the process.

17.  In raw state, the colour of chrome-tanned skin is blue.
 Masking agents are Carboxylic acids such as Acetic acid , used to suppress
the formation of Poly chromium.
 The entire tanning process involves chemical and organic compounds that
have an effect on environment. Chemicals that are used in tanning of leather
increases the production of Chemical oxygen demand and Total dissolved
salts in water when they are not treated and released in water bodies.
 Tanning process consumes large amount of water and produces a enormous
amount of waste.
 The other chemicals that majorly pollute in tanning industries are
Ammonium Sulphate , lime, Sulphuric acid, chromium salts and vegetable
tanning materials.

18.  STEP 1:- Cattles having high quality leather are sorted. The skin of these
Cattles are removed by manual process.
 STEP 2:- The skin is then put into a large container, containing sodium
chloride( common salt). The skin contains hair. This skin is commonly
referred to raw skin.
 STEP 3:- After few days, the skin is taken out from the tanker containing
sodium chloride and withered. The salt is removed manually from the skin.
 STEP 4:- LEATHER SOAKING : The leather is soaked in water which
contains 2% wetting agent based on its raw weight for 12 hours.
 STEP 5:- PEDALING : After 12 hours, the leather is put into a Pedaller
and is fed with 10% sodium liquor, 4% lime and is Pedalled for 12 hours.

23.  STEP 6:- After 24 hours, the hair from the leather is completely
removed. This stage is known as “Peet stage”.
 STEP 7:- The leather is then put into a big drum. ( 5% of (NH4)2SO4 or
NH4Cl ) is added.The drum is rotated for 30 minutes.
 At the end of 30 minutes, 1.2% of bi-sulphate is added. The drum is
again rotated for 30 minutes.
 1.8% of bat-barium-teluride is added. Now, the drum is again run for a
period of 45 minutes.
 STEP 8:- The leather from the drum is taken out and is examined by
adding phenolphthalein indicator.
 On adding phenolphthalein, if the pH is 8, lime is released and the
leather is white in colour else if the pH is 12 lime is not released and the
leather is dark brown in colour. In this condition, 0.1% of ammonium-
sulphate is added to reduce the pH to 8.

24.  STEP 9:- After examining, if hair is found, they are removed by manual
process. The examined leather is again put into a drum containing water.
8% salt is added to this leather : water mixture and stirred for 10
minutes.
 STEP 10:- Then 1% dilute H2SO4 is added and the drum is stirred
slowly for one hour.
 STEP 11:- The leather is removed from the drum and the pH of the
leather is checked again. The pH of the leather should not be more than
3. It should be within 2.5 – 3.
 STEP 12 :- 4% of Basic Chromium-Sulphate (BCS) is added and is
rolled in the drum for an hour. At the end of one hour, 4% of BCS is
again added and the drum is again rolled. Water is added after two hours.
Now, 1% of NaHCO3 and 1% of formate is added and rolled for one
hour.
 STEP 13:- The pH is again checked. The pH must be between 3.8 – 4.
Wet blue colour is obtained.

27.  STEP 14:- CHROME PENETRATION
 In this process, the presence or the absence of chrome is checked. If
chrome is absent in wet blue, then it is subjected to boiling test.
 Wet blue is the raw leather. It is then utilized for making many products
like leather belt, leather shoes, etc.

29. • SOAKING (Salt H2O)
The salt content in H2O is removed by polar bond by the addition of polar
atoms. H2O is then evaporated, the salt remains as sludge.
• ETP ( Effluent Treatment Plant )
 Pedaling
 Deliming
 Washing
 The water from all these 3 processes is treated by ETP process :
 Step1:- The pH of water from the manufacturing of leather is examined.
 Step2 :- Lime is added to it and the pH of water is maintained to 10.5
 Step3:- H2SO4 is added and the pH must be 8.

30.  Step 4:- Ferric alum is added and then pH of water is examined. The
pH must be 7 (neutral).
 Step 5:- Forma black, a settling agent is added. After sometime,
sludge will be settled at the bottom and then, water is separated from
it.
• AERATED TANK
o The water is sent into aerated tank which is rotated. During the
process, urea and super phosphate is added. DAB is added and water
overflows.
oThe pH of clean water must be 6 – 7 and should be treated by RO.
oHence, clean water is obtained and used for leather manufacturing.

31.  The chrome water is separated by the following processes :
 The chrome water from the leather manufacturing process
is pumped into a reactor. The pH must be 3.
 Then Magnesium oxide is added which may increase the
pH level from 6 – 7. The chrome will be settled as sludge.
 And, the processed clean water is obtained. The chrome
sludge which is settled at the bottom is removed and the
clean water is pumped out.

37. COMMON EFFLUENT TREATMENT PLANT

40. In order to minimize environmental pollution due to small and medium
scale industries , cleaness production , technologies and formation of waste
minimization circles are being encourged in India. Collective treatment at a
centralized facility, known as COMMON EFFLUENT TREATMENT
PLANT (CETP) is considered as a viable treatment solution to overcome
the constraints associated with effluent treatment in small and medium scale
industry. THE NUMBER OF CEPT IN INDIA :
ZONE NUMBER OF CEPT’S
NORTHERN ZONE 16
WESTERN ZONE 31
EASTERN ZONE 1
SOUTHERN ZONE 33
CENTRAL ZONE 6

41. Parameters Value Parameters Value
PH 5.5-9.0 Total
Chromium
2.0
Temperature 45 0C Copper 3.0
Oil and
grease
20 Zinc 15.0
Cyanide 2.0 Fluoride 15.0
Ammonical
nitrogen
50 Nickel 3.0
Phenolic
Compounds
5.0 Mercury 0.01
Hexavalent
compound
2.0 Cadmium 1.0
Inlet Effluent Quality Standards For CETP

42. EFFLUENT
AT INDIVIDUAL INDUSTRY LEVEL
High TDS and Low
COD
High COD and Low
TDS
CETP CETP

43. Process Involved In Common Effluent Treatment Plant
There are four steps involved in the process of CETP
1. Preliminary stage
2. Primary stage
3. Secondary stage
(i) Aerobic Process
(ii) Anaerobic Process
4. Tertiary stage
Preliminary Stage Includes :
(i) Screening
(ii) Grit Removal
(iii) Oil and Grease Removal

44. Primary Stage Includes :
i. Equalization
ii. Neutralization
iii. Sedimentation
Secondary Stage Includes :
Aerobic Process :
i. Activated Sludge Process
ii. Aerated Lagoons
iii. Trickling Filters
iv. Sequential Bath Reactor
v. Submerged Aerobic Fixed Film Reactor
vi. Membrane Bio-Reactor

45. Anaerobic Process :
i. Anaerobic Contact Reactor
ii. Up Flow Sludge Blanket
iii. Fixed Bed Reactor
iv. Biological Removal Of Heavy Metals
Tertiary Stage Includes :
i. Sand Filters
ii. Carbon Filters
iii. Micro Filters
iv. Ultra Filtration
v. Retention Ponds
vi. Nano Filtration
vii. Reverse Osmosis

46. Disposal of treated effluents from a Common Effluent Treatment can be done
in the following modes :
 Surface Water Bodies
 On Land For Irrigation
 Marine Outfall
 Public Sewers
 Availing of CETP sludge for agricultural use is acceptable, only when it is
free from hazardous constituents.
 The sludge from the biological treatment predominantly contains nutrients ,
thus could be availed as manure especially for dry lands and forest , thus
disposal rate can be controlled.

47. Several hazards may endanger the treatment plant , health and safety of
workers and may cause danger to the surrounding environment. Some of the
hazards are:
 Natural Hazards
 Accidental Hazards
• Enclosed CETP
• Electricity
• Fire
• Explosion
 Chemical Hazards
• Exposure to Chemicals
• Toxic Effects of Chemicals
• Safe Use of Chemicals
 Biological Hazards

48. BIOLOGICAL HAZARDS :
Many Disease are caused due to chemicals use in leather tanning industry,
some of the disease are :
i. Gastroenteritis – Cramping, stomach pain, diarrohea, vomiting
ii. Weil’s Disease – Flu like illness, damage to liver, kidney and blood
iii. Hepatitis – Inflammation of the liver and jaundice
iv. Infection to skin and eye
v. Dry cough
vi. Throat Inflammation
vii. Chest Congestion
viii. Nasal Catarrh
ix. Chronic Bronchitis
x. Allergic Bronchitis
xi. Asthma
xii. Sinusitis
xiii. Pulmonary Tuberculosis

49.  The tanning industry poses many dangers to both the environment and those
that work within it.
 The primary environmental threat involves the dumping of solid and liquid
waste that contains leftover chromium and other hazardous compounds.
 Direct Impacts : It occurs through direct interaction of an activity with an
environment . Discharge of effluent from CETP into a river may lead to a
decline in the quality of water in terms of high BOB or DO or rise of water
toxins or rise of TDS.
 Indirect Impacts: Ambient air SO2 rise due to stack emission may deposit
on land as SO4 and cause acidic soil. Decline in water quality due to rise in
temperature of water bodies receiving water discharge from the nearby
industry. It may lead to a secondary indirect impact on aquatic flora in that
water body and may further cause reduction in fish population, Indirectly
the income of fishermen is affected.
EFFECTS :

50. THANK YOU!