Super Tannery Ltd, is the world’s leading Buffalo leather tannery and specializes in the manufacture of high quality leather for Automotive & Furniture Upholstery, Safety & Lifestyle Footwear, Bags, Belts, Sporting Goods and Equestrian equipment.

1. Aman Anand Shreechand
Rajat Chaubey
Josh Babu
Shekhar Kumar Sah

2. Set up in 1953, Super Tannery is the oldest tannery in Kanpur,
India and enjoys a high reputation in the world markets.
Super Tannery Ltd, is the world’s leading Buffalo leather tannery
.and specializes in the manufacture of high quality leather for
Automotive & Furniture Upholstery, Safety & Lifestyle Footwear,
Bags, Belts, Sporting Goods and Equestrian equipment.

3. This is on account of population of 194 million cattle
1. 70 million buffaloes,
2. 95 million goats.
3. 48 million sheeps, it claims the sixth position. These three species provide the
basic raw material for the leather industry.
The annual availability of 166 million pieces of hides and skins is the main strength of
the industry. This is expected to go up to 218 million pieces by the end of year 2020.

4. The preservation of hides and skins in a tannery can be split into following
four main categories:
• Preservation of hides and skins storage
• Beam house operations
• Tanning operations
• Post-tanning and finishing operations

5. Furthermore, tanneries employ abatement techniques for the treatment of wastewater,
solid waste and air emissions generated during these processes. Operations carried out in
the beam house, tanyard, and post-tanning areas are often referred to as wet processes,
as they are performed in processing vessels such as drums. After post-tanning, the
leather is subjected to dry finishing operations.
Processes employed in each of the above categories change depending on the raw
materials used and the final desired products. Hence the environmental impacts vary
from tannery to tannery and a more detailed assessment is necessary at each unit/sit

7. •RE-TANNING OPERATIONS
1. Raw hides/skins
Usually, the hides/skins consist 65% of the water and 30-35% proteins and fat.
Because of the high amount of moisture in the hides/skin, there will be bacterial
degradation. In order to prevent this bacterial activity, the moisture content should
be brought down to less than 30%. This dehydration is usually done by applying
common salt (i.e., Sodium Chloride) to the hides/ skins to the tune of 30-45% by
weight.
2. Sorting
Hides and skins are sorted into several grades by size, weight, or quality.
3. Trimming
Trimming is generally carried out during the sorting process. Some of the edges
(legs, tails and heads, etc.) of the raw hides and skins can be cut off. Usually this is
done in the abattoir, but it can also be carried out in tanneries.

8. •Curing and storing
Curing is a process that prevents the decomposition of hides and skins from the time
they are flayed in the abattoir until the processes in the beam house begin.
Whenever a raw material cannot be processed immediately ("green"), it must be
cured. Popular methods of long-term preservation are salting and drying.
•Soaking
The main purpose of this process is to remove the salt used during curing, re-
hydrating the material and to get rid of unwanted materials such as dung, blood,
soil, etc. The duration of soaking may range from several hours to a few days.
Depending on the type of raw materials used, soaking additives such as surfactants,
enzyme preparations and bactericides can be used.

9. •Liming
The purpose of this operation is to facilitate the removal of hair, flesh, fat
(partially), inter- fibrillary protein and to open-up the fibrous structure for
osmotic swelling.
Fleshing
The excess fleshing is removed manually or by using fleshing machines. The
quantity of wet fleshings is in the range of 10-15% of the weight of raw
hides/skins
De–liming
This is a process to adjust the pH in between 8-8.5 in order to enhance the
enzymatic activity, which converts some of the proteins into soluble forms. pH
correction i.e., from 12-12.5 to 8-8.5 are done by using ammonium chloride in
case of soft leather and ammonium sulphate in case of hard leather.
Pickling
Pickling is a process of correcting the pH suitable to the tanning operation and to
prevent swelling of the leather i.e. dehydration of the leather. In this process,
water (80%), salts (8-10%), formic acid (0.28- 0.3%), sulphuric acid (0.75 – 2%
based on thickness) are applied.

10. •TANNING OPERATIONS
The tanning process is of two types i.e., chrome tanning and vegetable
tanning. Of the total leather production in India, more than 80% is based on
chrome tanning and the rest is based on vegetable tanning.
•Chrome tanning
Basic chromium sulphate [Cr2(SO4)3] (7-10 %) containing 25% Cr2O3 and sodium
sulphate (25- 30%) is used in chrome tanning. Part of the pickle bath is used
for chrome tanning operation. The pH is increased to 3.8-4.0 at the end of
chrome tanning process which is called basification. The semi-finished leather
after chrome tanning is called wet blue.
•Vegetable tanning
Plant extracts are used for the purpose of tanning in this process. The pH falls
down from 4- 4.5 to 3-3.5. This process is free of any heavy metal use, the
leather developed from this process has comparatively weaker capacity of
heat resistance and dye-holding.

11. •POST-TANNING OPERATIONS
Post-tanning operations comprise of re-chroming of semi-finished wet blue
leather.
Sammying: It is a mechanized process followed to remove excess moisture in
the wet blue.
Splitting: After sammying, the material is split into required thickness using
splitting machine
Shaving and Trimming: The semi-finished leather is leveled using the shaving
machine.
Re-chroming: Depending on the quality of wet blue, re-chroming is carried out
to improve the chromium content in the leather.

12. Semi-chroming: Incase of
vegetable tanned semi-finished leather, chrome
tanning is given
depending on the final leather quality.
Neutralization: pH is adjusted to 4.5-6.5
Dyeing: The leather is colored using dyes such as anionic dyes, acid dyes,
direct, metal complex compounds and basic dyes.
Fat-liquoring: Natural/synthetic oils are applied for fat liquoring, thereby
imparting softness to the leather
Finishing: Phenolics, melamine, acrylics, polymers, naphthalene, etc., are
used for finishing to impart fullness to the leather

14. ENVIRONMENTAL ISSUES AND PREVENTIVE METHODS
Environmental issues associated with tanning and leather finishing include the
following
•Waste water
•Air emissions
•Solid waste
•Hazardous materials
Water usage
Water plays a vital role in tannery operations. Approximately 30-40 liter (L) of
water is used for processing one kilogram (kg) of raw hide/skin into finished
leather.

15. Biological wastewater treatment
Various physiochemical techniques used for wastewater treatment can be
applied to tannery wastewater (to the entire process or to individual step
in the process) but these processes are expensive. Biological treatment of
wastewater is more favourable and cost effective as compared to other
physiochemical methods.

16. Aerobic Treatment
Aerobic microorganisms use organic carbon in the effluent and convert it to
biomass and carbon dioxide. A large amount of sludge is generated along with
high energy consumption the process. Aerobic treatment of tannery wastewater
reduces chemical oxygen demand (COD) by 60-80% and biological oxygen demand
(BOD) reduction is 95%, when combined with physicochemical pretreatment [2].
In a combined biochemical oxidation and chemical coronation step, chemical
oxygen demand (COD), total nitrogen (TN) and total suspended solids (TSS)
removals of 96%, 92% and 98%, respectively were obtained.

17. Anaerobic treatment
Anaerobic treatment of wastewater converts the organic pollutants into a
small amount of sludge and large amount of biogas (methane and carbon
dioxide).The sulphide present in wastewater inhibits the anaerobic
treatment. Methanogenic bacteria are inhibited by sulphide, whereas
acidifying and sulphate reducing bacteria do not inhibit.

18. Chemical wastewater
Chemical waste water treatment is an individual process that is employed
to remove substance and bacteria’s from raw sewage and rain water runoff
waste water treatment facilities filter used dirty water , so that it can be
recycled back in to natural artificial water sources . Numerous chemicals
are used in different phase of the filtration process to separate out solids,
kill bacteria and parasites’ and remove dangerous toxins.

19. Chemical oxidation method
Chemical oxidation allows in general complete elimination of the
principal organic pollutants but complete removal of total organic carbon
is more difficult .The oxidation of phenol with a power full oxidant such as
ozone allows only a 30; total organic carbon removes similar level of total
organic carbon removal are obtained using H2O2 at room temperature .
Ozonisation
Ozone is a gas at normal presser and tempreatur .Its solubility in water is
function of its partioal pressur and temperature. Ozon is generated by high
voltage discharge in air and oxygen. Ozone is unable and to tends to react
to form [6] O3 + H+ + e- O2 + H2O Ozone is a very strong oxidizing agent
and it is very effective as a decolouration agent and as oxidant of organic
material.

20. Electro chemical method
Electro chemical oxidation has been reported to be have in similar way .we
have demonstrated that the total organic carbon (TOC) Removal obtained by
the electro chemical oxidation at a platinum anode is higher than that
obtained by chemical oxidation. This higher Toc removal using electro chemical
oxidation has been attributed to the oxidation of adsorbed organic compounds
to carbon dioxide

21. A physical waste water treatment process does not add any chemical
components or biological material to treat .The water can be screened to
filter out large object. It can also treated by means of sedimentation,
during which solids settle to the bottom under the effluence of gravity
.Water that is free of can be then be remove. Other physical process
includes the addition air to provide oxygen within the waste water and the
water can also be passed through filter to get rid of solid material. There
are three method of physical waste water treatment . these are
Mechanical treatment, Effluent treatment, Post-purification, and
sedimentation a Sludge handling.

22. Mechanical treatment
Usually the first treatment of the raw effluent is the mechanical treatment
that Includes screening to remove coarse material. Up to 30-40% of gross
suspended solids in the raw waste stream can be removed by properly
designed screens. Mechanical treatment may also include skimming of fats,
grease, oils and gravity settling .
Effluent treatment
In order to carry out effluent treatment in the most effective manner, flow
segregation is useful to allow preliminary treatment of concentrated
wastewater streams, in particular for sulphide- and chrome-containing
liquors. And although a reduction of water consumption does not reduce the
load of many pollutants, concentrated effluents are often easier and more
efficient to treat. Where segregation of flows is possible, thorough mixing of
chrome-bearing effluents and other effluent streams improves the efficiency
of the effluent treatment plant because the chromium tends to precipitate
out with the protein during pretreatment

23. Post-purification, sedimentation and sludge handling Post-purification,
sedimentation and sludge handling are the last step in wastewater from
the water phase by gravity settlement. After dewatering this sludge by
means of filter presses, a sludge cake with up to 40% dry solids can be
achieved, whereas belt presses produce a sludge cake with up to 20-25%
dry solids

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united nations industrial development organization (UNIDO), Vienna, 2011
2. Jalandhar,” Biological Treatment Of Tannery Waste Water For Sulphide
Removal”, Int. J. Chem. Sci. 2008, 6,472-486.
3. Gmbh, Frankfurt” Treatment Of Tannery Wastewater” 2002, 30,115-120.
4. D.R.F Harlemen, S. Murcott” The Role of Physical Chemical Treatment in the
MegaCities of the Developing World”. Water science and technology, 1999,
40, 75-80.
5. Ldil Arslan-Aloton, Assoc.Prof.Tugba OlmezHancl.’’Chemical Oxidation
Applications For Industrial Waste Water’’. Iwa publishing .year 2002, 8 , 89-
80.
6. V.Baratharat ,’’ The Ozone Technology And Systems” India ,pvt Limited Che
Nnal
7. Guohuachen.’electrochmical Technigue In Waste water Treatment,
Separation And Purification Technology, 2004, 38, 11-41.
8. Sarkar, K.T., Practice of Leather Manufacture, Oxford University Press,
London, 1962