Forum Program

INNOTECH

Technology for
Sustainability
the challenge in leather manufacturing

FORUM INTERNAZIONALE
I N T E R N AT I O N A L F O R U M

20
Ottobre / October
2011
Fiera di Bologna

ASSOMAC SERVIZI srl
P.O. Box 73 PTB - Via Matteotti, 4/a - 27029 VIGEVANO - PV - ITALY
Tel.: +39 0381 78883 - Fax: +39 0381 88602 - exhibition@assomac.it

PROGRAM
9,30 Registration

9.40 Welcome Address

10.00 UNIC Environmental Report 2011 Presentation
(Salvatore MERCOGLIANO - UNIC Director)

10.10 INTRODUCTION (Sergio DULIO – ASSOMAC)

KEYNOTE SPEECH
Sustainable Leather Prospective:
Realistic Objectives and Future Opportunities
(Heinz-Peter GERMANN - Lederinstitut Gerberschule Reutlingen Director)

10.50 Coffee Break

11.00 EXPERTS’S SPEECHES (moderator Sergio DULIO - ASSOMAC)

Ananthakrishna SAHASRANAMAN - Environmental Management Company of Tanners
The Indian Experiences in Environmental Management

Zhongbai GAO – China Leather & Footwear Industry Research Institute Director
Prospect of Clean Technology in Process of Leather China Production

Daniele REFOSCO – Techical Director Cluster Waste Water Treatment Implant
Acque del Chiampo, Italian Cluster Experience in Integrated Waste Water Treatment

Angelo Borrini- Consorzio Cuoio-Depur S.p.A.
Solid Waste Treatment, FERTILAND Project

Sandra VITOLO - University of Pisa
Evaluation of Environmental Impact of Leather Process Using LCA Methodology

13.00 CONCLUSION

KEYNOTE SPEECH
Sustainable Leather Prospective:

Dr. Ing. Heinz‐Peter GERMANN

PROFESSIONAL HISTORY:

Study of chemistry and Doctoral thesis in the field of collagen and peptide chemistry at the
Technical University of Darmstadt (supervisor: Prof. Dr. Eckhart Heidemann)

1987 – Research scientist and lecturer at Westdeutsche Gerberschule Reutlingen (West
German Tanners’ School, Reutlingen – ‘WGR’)

1990 – Head of Research & Development department at WGR

1993‐2011 – Director of the Institute “Lederinstitut Gerberschule Reutlingen, LGR” (formerly
WGR) – the German Training, Testing & Research Centre for the leather industry

MEMBERSHIPS AND HONORARY OFFICES:

Since 1992 – Member of the Scientific Council of AiF (union of industrial research associations)
1993‐1994 – President of GERIC (group of the European leather research institutes)
Since the 1990’s – Member of the Board of VGCT (The German society of leather chemists and
technologists)
1994‐1997 – President of VGCT
2000‐2011 – Treasurer of VGCT
1997‐2011 – Chairman of the VGCT Prize Committee
Since 1994 – Sworn Expert in the field of leather industry (appointed by the Chamber of
Commerce and Industry)
Since 1995 – Deputy member of the board of control of the Steinbeis‐Stiftung, Baden‐
Wuerttemberg (public foundation for the stimulation of economics)
1998‐2010 – Central European representative in the Executive Committee of the International
Union of Leather Technologists’ and Chemists’ Societies (IULTCS)
“John Arthur Wilson Memorial Lecture” (American Leather Chemists Association (ALCA) –
delivered in 1997
“Procter Memorial Lecture” (Society of Leather Technologists and Chemists (SLTC), UK) –
delivered in 2008
“B.M. Das Memorial Lecture” (Central Leather Research Institute (CLRI), Chennai, India) –
delivered in 2010
“Heidemann Lecture” (International Union of Leather Technologists’ and Chemists’ Societies
(IULTCS) – to be delivered in September 2011, Valencia/Spain

Program and Documentation

Sustainable Leather Manufacture:

Dr.-Ing. Heinz-Peter Germann
N-Zyme BioTec GmbH, Innovation Center Leather & Collagen, Reutlingen/Germany

Sustainable development is a pattern of resource use that aims to meet human needs while
preserving the environment so that these needs can be met not only in the present, but also
for future generations. Practical approaches to realizing the idea of sustainable development
in manufacturing companies are mainly followed up by cleaner production which includes
reduction of energy use, use of renewable resources, minimization of water consumption
and reduction of waste generation.

In leather manufacturing e.g. increased use of fresh uncured or chilled hides for processing,
application of ecological liming systems and proper selection / intelligent use of tanning
agents have been important steps towards environmentally compatible production.

However, the ‘destination’ of sustainability is not a fixed place in the normal sense that we
understand destination. Instead, it is a set of wishful characteristics of a future system as
pointed out earlier.

So, what are the future challenges for sustainable leather manufacture?

o In principle, leather manufacturing is in itself ‘recycling’ – i.e. it is a sustainable
solution to the disposal problem of a by-product that originates from the meat industry.

o The concept of ‘globalization’ in leather production has to be adjusted by taking more
into account additional factors like e.g. raw material sourcing that is also relevant to the
subject of sustainability.

o Sustainability of leather manufacture can be further increased by using resources (i.e.
water, fossil fuels and other natural resources) sparingly, which includes controlling the
production processes and improving the systematic re-use of by-products whenever
possible, and giving priority to the use of renewable resources.

2

The Indian Experience in Environmental Management

Dr. Ing. Ananthakrishna SAHASRANAMAN:

Vice Chairman,CEMCOT ‐ Chennai, India

A post graduate in Economics, Mr. Sahasranaman has published numerous papers on various
aspects of leather industry in India and globally too. He has authored one book titled
‘Environment Management – A study of the Tanning Industry in India’

As a retired officer of the Indian government, Mr. A. Sahasranaman had held many important
positions in the region of Jammu and Kashmir and in the Government of India, mainly in the field
of industrial development, between 1973 and 1996.

Mr. Sahasranaman’s association with the Indian leather industry started in 1985 when he became
the Executive Director of the Indian Council for Leather Exports in Chennai. After playing a
significant role in transformation of Indian leather industry from one of raw material exporter to a
major exporter of value added leather products, Mr. Sahasranaman joined United Nations
Development Programme, India, to implement a large scale development project for the Indian
leather sector. This programme contributed to strengthening existing institutions for human
resources development in the country by forging collaborations with like institutions in Europe
and Australia. An innovative marketing campaign in the USA and improving environment
management in the leather industry were other major components of this project.

As the Programme Coordinator of UNIDO’s (United Nations Industrial Development Organization,
Vienna) ‘Regional Programme for Pollution Control in The Tanning Industry in South East Asia’
covering Bangladesh, China, India, Indonesia, Nepal and Sri Lanka, Mr. Sahasranaman contributed
significantly to introducing new cleaner and end of pipe technologies for tackling solid and liquid
wastes of the leather industry in all these countries.

For the past three years, Mr. Sahasranaman has been closely involved with Chennai
Environmental Management Company of Tanners (CEMCOT) at Chennai, India, first as its
Managing Director and later as the Vice Chairman of the Board of Directors. CEMCOT is engaged
in setting up six large ‘Zero Liquid Discharge’ common waste treatment plants, at an estimated
cost of Euro 30 million.

3


CHENNAI ENVIRONMENTAL MANAGEMENT COMPANY OF TANNERS
http://www.cemcot.com/ Chennai Environmental Management Company of Tanners (CEMCOT) is a Special
Purpose Vehicle (SPV), incorporated as a not‐for‐profit company, registered under the Indian Companies
Act 1956, formed by the six common effluent treatment plants in Tamil Nadu, to implement certain
infrastructure projects, namely establishment, operation and maintenance of zero liquid discharge (ZLD)
systems for seven common effluent treatment plants in the state of Tamil Nadu under the Indian Leather
Development Programme (ILDP) Scheme of Department of Industrial Policy and Promotion (DIPP),
Government of India (GoI) and Government of Tamil Nadu (GoTN). The company was incorporated on 15
July 08 in Chennai.

4

Sustainable Development of China Leather Industry

Prof. Dr. Zongbai GAO:

Professor of China Leather & Footwear Industry Research Institute (CLFI),
Deputy Director of CLFI‐ member of CLIA, Beijing China

Degree in Chemical Engineering at the University of Padua in 1981.
Responsible of Clean Technologies and Environmental Technologies in CLFI

Working Backgrounds:
From 1986 until now CLFI Research Institute Professor
From 2006 until now Tianjin Science & Technology University Visiting Professor
From 2002 until now Shanxi Science & Technology University Visiting Professor
2000 British Leather Technology Centre Visiting scholar
1999 TNO‐MEP, Environmental Sciences, Energy Visiting scholar
Research and Process Innovation, The Netherlands
1999 Environmental Department, Wageningen Visiting scholar
University, The Netherlands
1995 British Leather Technology Centre Trained
Leather Department, Northampton University, UK

2004, Specialists who enjoy the special government allowance granted by the state council.
2007, Application China National Patent for an Invention”Recycle Method of the Leather
Waste”CN:200710099422.9.
1995‐1999, Take charge of the UNIDO Project, （US/CPR/92/120）.
1999‐ 2004, Take charge of the Netherlands Government Project（CN012502）and Extension
Project（No. 10554）
5


The China Leather and Footwear Website WWW.LEATHER365.com and China
Leather and Footwear International Industrial.

Subcontracting And Exchange Network (www.clfpx.com) are built by the Centre

6

Leather Cluster Experience in Integrated Waste Water Treatment

Dr. Ing. Daniele REFOSCO:

1998‐2011 – Technical Director of the Wastewater treatment implant
Acque del Chiampo S.p.A. of Arzignano leather cluster district , Italy

Degree in Chemical Engineering at the University of Padua in 1981.
From 1982 he worked in industry, with experience in production of chemical,
pharmaceutical industry and in the environmental field, both as a designer in a
major study of civil and environmental engineering and as a technical manager in a
companies design, construction and management, particularly of sewage treatment
plants Civil and industrial waste and waste disposal.

7


http://www.acquedelchiampospa.it
Arzignano wastewater treatment implant

160 tanneries directly connected to the system
40,000 residents of seven of the ten municipalities of the valley of Chiampo

8

Solid Waste Treatment, FERTILANDIA Project

Dr. Ing. Angelo BORRINI:

Director of Consozio CUOIO‐DEPUR, San Miniato‐ Pisa Italy
The Fertilandia project is co‐financed by the Eco‐innovation programme of the European
Commission. The Eco‐innovation programme supports innovative solutions protecting the
environment, supporting market replication projects of products, processes or eco‐innovative
practices, already technically proven, but needing incentives to have success in the market.

9


http://www.cuoiodepur.it/

Utilization of tannery working by‐products
• Cuoio Depur, through new society CCT specially born, intents to collect solid by‐
products come from tanning process and treating, in according with the rule CE
1774/02, to obtain leather‐meal mixed with stabilized proteic sludges, for the
production of the fertilizers line derived from “Pellicino Integrato”. For this
purpose a technology system globally costing € 1,400,000 is being realized. The
project will make possible closing cycle of tannery working solid by‐products.

10

Evaluation of Environmental Impact of Leather Process
Using LCA Methodology

Prof. Ing. Sandra VITOLO:

Since 1995 professor of Chemetry and Industrial Chemestry in Chemical
Engineering degree course and in Industrial Engineering degree courses.
Actually Director of Environmental Department ‐ University of Pisa Italy

Sandra Vitolo graduated with maximum votes in Chemical Engineering at the University
of Pisa in 1989. After experience in the process industry, she entered the Department of
Chemical Engineering, Industrial Chemistry and Materials Science in the University of Pisa
as a Research Assistant in 1992 in the Industrial Chemistry and Technology sector. From
september 2000 up to December 2004 she is Associate Professor in the same sector and,
from January 2005 she is full professor. Her research is performed in the field of the
industrial chemistry of liquid effluent treatments, gas treatment, thermo‐chemical
conversion of bio‐masses and sustainability of the leather industry.

11


12

Tannery Industry
Guidelines for a more sustainable
BEAMHOUSE & TANNING PROCESSES

Reduction in tannery wastewater: Chloride, Sulphate, Chrome Tanning

Published in 2007 A.T.O. Valle del Chiampo
A.A.T.O. Bacchiglione

Guidelines published in 2007. This work was the result of the impact assessment of tanning process in
the Arzignano district, specifically drawn to indicate the need for a better control of wastewater
entering in the treatment plant and meet parameters in the output according to the Italian Regulation.
A special thanks is due to Mr. Hans George Hoerter, Dr. Raoul Sartori and the late Dr. Umberto
Sammarco for their availability in the drafting of the Guidelines
by courtesy of Acque del Chiampo SPA

Translation and Reprint by ASSOMAC SERVIZI S.r.l.

2

Summary

1. GUIDELINES FOR THE CHLORIDE REDUCTION in Tannery wastewater..........................4
1.1.CHLORIDE from CONSERVATION of RAW HIDES.....................................................4
1.1.1. Skins whisking ...............................................................................................4
1.1.2. Using fresh raw hides ...................................................................................4
1.2.CHLORIDE REDUCTION IN PICKEL............................................................................5

2. GUIDELINES FOR THE SULPHATES REDUCTION in Tannery wastewater.........................6
2.1. REDUCTION OF SULPHATES ORIGINATED FROM OXIDATION OF SULPHITE..........6
2.2. REDUCTION OF SULPHATES IN DELIMING..............................................................7
2.3. REDUCTION OF SULPHATES IN PICKEL ...................................................................7
2.4. REDUCTION OF SULPHATES IN TANNING...............................................................8
2.5. REDUCTION OF SULPHATES FROM DYES and RETANNING AGENTS .....................8

3. GUIDELINES FOR THE TANNING CHROME REDUCTION in Tannery wastewater ...........9
3.1. CHROME RECOVERY ...............................................................................................9
3.2. OPTIMIZATION OF THE CHROME FIXATION .........................................................10
Amount of chromium salt (in Cr2O3) ...................................................................10
Float, long ..............................................................................................................11
Final temperature of tanning ................................................................................11
Duration of tanning ...............................................................................................11
pH of the end tanning............................................................................................11
Masking..................................................................................................................11

CONCLUSION ........................................................................................................................12

3


1. GUIDELINES FOR THE CHLORIDE REDUCTION in Tannery wastewater
Sodium chloride is mainly used in the tanning process preservation of raw hides and during
pickling to suppress the acid swelling. The environmental impact of chlorides, respect to the
two phases mentioned above, has a different incidence.

1.1. CHLORIDE from CONSERVATION of RAW HIDES
The amount of salt needed to ensure a long‐term safe storage amounts to
about 30% by weight of raw hides. It is estimated that over 70% of chlorides
present in wastewater of the entire production process comes from salt used
for leather conservation.
The methods of treatment for this pollutant are very expensive even for high
investments and for the requested high energy contribution. At this time the
replacement of salt with other products and/or alternative non‐polluting
methods is still not yet feasible at large scale, therefore the reduction of sodium
chloride used when salting can be done by implementing the following Best
Available Techniques.

1.1.1. Raw hides beating

The salt quantity that can be eliminated through this approach is related to the
raw hides provenience and approximately can be calculated on the weight of
raw hides. The amount of salt removed by this operation varies depending on
the origin of the raw between 6 and 12% calculated on the weight of the raw
hide. To increase the efficiency of the operation it is recommended to increase
the beating time and decrease the inclination of the drum. A system for
verifying the effectiveness of beating is to run an occasional re‐whisking of
lower rates of skins. The weight difference found between the first and second
the operation should not exceed 1%.

1.1.2. Using fresh raw hides

The contribution in reduction of chlorides into waste water processing fresh
raw hides is evaluated at least 40%. In a mixed production (50% and 50% of
freshly salty) you can get a reduction of over 20%. Many European countries
use fresh skin for a long time in significant quantities.

On the other hand, for the processing of fresh hides must be taken into
consideration a few things:
• Italian tanneries may have fresh supplies of hides only from Europe;
• Substantial supplies are not in case of substantial price fluctuations.

4

• The skin should be kept at a temperature of 2° C during transport and storage
in the tannery;
• Storage can not be continued for longer than 7‐8 days;
• The need to keep your skin at low temperatures is really expensive related to the
energy consumption.

The limitations related to the process of fresh raw hides may be muffled with a
rigorous organization. Beyond the limits listed above first, however, be solved with
proper business organization, processing of hides presents fresh following
advantages:
o the stock does not present fairly common defects due to salting (spots, damage
the grain);
o the authenticity of origin can be identified more easily;
o the elimination of row hides beating and manage of the salt waste.

1.2. CHLORIDE REDUCTION IN PICKEL
The bath density, compared with common average in use (8‐9 °Bé), can be
reduced significantly anyway avoiding the acid swelling. A density of 6.0‐6.5 °Bé
ensures proper execution of this operation. This parameter will be checked each
time, after a rotation of 20 minutes by the addition of salt. To further reduce the
amount of salt it is necessary to work in a fairly short float. The 20‐35% on the
pelt weight (depending on whether you use liquid chrome or powder) is more
than enough, since the substantial increase in volume resulting from the addition
of diluted acid. For safe operation it is advisable to recheck the density even after
the addition of acids.
It must not be less than 5.5 °Bé, this value still guarantees maximum operational
safety. Moreover, it is known that non high density values produce a better
quality leather.
Another benefit from the short float is an increased speed of the acids in crossing
of the leather section, resulting in time savings that can be conveniently used in
the later stage of tanning. These measures allow a drastic reduction of the salt
used in pickling (30%), which can be quantified in a decrease of about 10% of the
total chloride discharge ¹.

¹ Calculated assuming the use for each kilogram of raw skin of 25 liters of water for a complete
processing cycle, an average content of 3000 mg/l of sulfates of 7000 mg/l of chloride and 200 mg/l Cr in
the effluent at the end of the process.

5


IMPACT OF CHLORIDE IN THE DRAINAGE

7.000
7.000

6.000
mg/l of drainage.
4.835 4.855
5.000

4.000
3.398

3.000
2.165
2.000
1.456

1.000

0 Chloride reduction
Conservation salt Pickel salt Total Traditional
Innovative

2. GUIDELINES FOR THE SULPHATES REDUCTION in Tannery wastewater
The predominant amount of sulphates present in wastewater comes from the deliming,
pickling, tanning phases as well as from sulfur present in the effluent at the end of liming,
which turns into sulphates during depuration phases. Less significant contributions of
sulphate, especially when the complete cycle is carried out, are due to the dyes and retanning
used.

2.1. REDUCTION OF SULPHATES ORIGINATED FROM OXIDATION OF
SULPHITE
It is known that sulfide from wastewater by liming may be oxidized to sulphate
during water purification. Assuming that oxidation is complete, the reduction of
1% of the sulfur offer in liming phase would determine a reduction of sulphate
in wastewater of about 300 mg/l ¹.
The main systems, which allow the reduction of the sulfur supply, are based on
the following measures:
Simultaneous use of assisting substances. They enable an efficient hair
removal using a total amount of sulfur and hydrogen sulphate equal to
2‐2.5%;
Reintroduction of the hair recovery. This technique allows a liming
with a total offer of sulfur and hydrogen sulphate equivalent to 1.5‐
2.0% compared to the traditional 3.0‐3.5% used for liming with hair
destruction. Swelling and turgescence can be adjusted by adding
dilute caustic soda. The hair recovery also helps the not inconsiderable
advantage of a load reduction of COD, TKN and suspended solids;

6

Recovery and reuse of the bath at the end of liming appropriately
reintegrated with lime and sulfur. Obviously, in this case the emissions of
sulfur and consequently of sulphate will be reduced to a minimum. This
system saves a vital resource like water and about 20% of sulfur and lime.
Spending on plant recovery could be depreciated quickly enough due to
less consumption of agents liming. The lower use of sulfur allows a
reduction of the reagents used for the abatement of emissions during the
deliming and pickel phases.

2.2. REDUCTION OF SULPHATES IN DELIMING
At this stage sulphates come from ammonium sulfate, which is the most widely used
deliming for reasons of price, better speed cross section and for his buffering effect.
Really, the pH of the bath never drops below the safety threshold when this product is
used as deliming agent. Unfortunately, it also helps to raise the effluent TKN values. On
the other hand, the deliming of full thickness heavy hides using products free of
ammonium salts is hardly feasible, as the lead times of the process would be too long.

It’s realistic, and industrially feasible, the partial replacement of this salt, at least 50%,
with products based on alternative mixtures of dicarboxylic acids and / or organic
esters.
This measure would lead to a reduction of over 10% of sulphates present in the
effluent in the entire processing cycle.
It should be stressed that the new generation deliming allows to make a full thickness
skin deliming with a supply of ammonium sulphate of about 0.5% versus 2.5% medium
used. This means to reduce the contribution of sulphates in the effluent of 580 mg / l, a
value corresponding to about 20% of total ¹. The use of these products also offers the
advantage of obtaining better items in quality compared to those obtained by making
deliming with ammonium sulfate used alone.

2.3. REDUCTION OF SULPHATES IN PICKEL
Unfortunately there isn’t now a viable alternative for replacing sulfuric acid during
pickling. On the other hand, the contribution of sulfate due to the use of this acid has
been estimated about 500 mg / l in wastewater, ¹.
The use of precise instruments (pH meters) to control the degree of acidity of the
pickling solution avoids an excessive unwanted use of sulfuric acid.
Even a very well done deliming and a washing very efficient at the end of maceration
allow the attainment of pH desired end pickel with and the cross section of the skin,
without unnecessary waste of sulfuric acid.

¹ Calculated assuming the use for each kilogram of raw skin of 25 liters of water for a complete processing cycle,
an average content of 3000 mg/l of sulfates of 7000 mg/l of chloride and 200 mg/l Cr in the effluent at the end of
the process

7


2.4. REDUCTION OF SULPHATES IN TANNING
The improvement of the chrome exhaustion in the tanning allows the
reduction of supply. This eventuality offers a considerable economic advantage.
By reducing the supply of chrome, respectively 1% as powder or 2% as liquid
(13%), the contribution of sulphates in wastewater is reduced to about 200
mg/l, which represents a decrease of over 6% of the total amount of sulphate in
the effluent end of pipe.
In fact, it’s known that every kilogram of chrome powder (25% of Cr2O3)
contains 540 g of basic chromium sulphate and at least 300 g of sodium
sulphate, corresponding to 314 g and 203 g of sulphate ion. This means that
reducing the supply of chromium by 1% of chromium a total decrease of 517 g
of sulphate is obtained, equivalent to about 200 mg/l of sulphate in the effluent
of the complete working cycle ¹.

2.5. REDUCTION OF SULPHATES FROM DYES and RETANNING AGENTS
It’s not possible to quantify, in a reliable way, the contribution of sulphates of
the dyes and retanning agents used during post‐tanning, because the applied
formulations change within wide limits depending on the tannery and the final
product. Generally dyes can contain sodium sulphate (Na2SO4) and sodium
chloride (NaCl) in quantities between 10 and 30%, although in certain cases
higher levels have been found. Assuming to use a dye containing 30% by weight
of sulphate and dosing that in 4% on the weight of shaved cattle hides to mm.
1.2/1.4, the amount of sulphate in wastewater would amount to a total of
about 100 mg/l1,2.
Some products used in re‐tanning such as resins, synthetic tannins, re‐tannings
and dispersants often contain significant amounts of sulphate. It's therefore
preferable to use high concentration products and therefore with a low content
of sulphates and chlorides.

¹ Calculated assuming the use for each kilogram of raw skin of 25 liters of water for a complete processing
cycle, an average content of 3000 mg/l of sulfates of 7000 mg/l of chloride and 200 mg/l Cr in the effluent
at the end of the process.
² Calculated considering the dyeing of 1 kg of wet‐blue, shaved 1.3/1.4 mm. corresponding to 4 kg. raw
hides

8

IMPACT OF SULPHATE IN THE DRAINAGE

5.000 4.881
Sulphate reduction

4.500 Traditional
Innovative 3.946
4.000

3.500
mg/l of drainag

3.000
2.500
2.500 2.300

2.000

1.500
1.051
1.000 751 730
500 500
500 365
100 30
0
Liming Deliming Pickel Tanning Dyeing Total

3.GUIDELINES FOR THE TANNING CHROME REDUCTION in Tannery
wastewater
The reduction of chrome in water at the end of tanning may be primarily done in 2 ways:
chrome recovery by precipitation with alkali and redissolution in sulfuric acid.
Chrome regenerated with new fresh tanning agent is used in the subsequent
chrome tanning phase.
optimization of the efficiency of chrome fixation to leather and exhaustion of the
tanning baths.

3.1. CHROME RECOVERY
This system has some limits:
wastewater spill of significant quantities of chromium, physically not cross‐linked into
the skin;
the need to have a recovery plant;
the not economically advantageous applicability for small and medium‐sized
productions;
the need to carry out continuous analytical monitorings of chrome obtained;
the inapplicability in the production of certain types of articles of high quality range.
The first point limits ecological performances of this method. In fact, we must point
out that using this system, at the end of tanning chrome not chemically bound is
contained in the skin.
The amount of chromium adsorbed at a physical level is proportional to the
concentration of tanning agent left in the bath at the end of tanning.
The highest the concentration is, the highest the amount of spilled chrome is in
waste water through the setting out operation after washing and shaving.

9


While the squeezing bath may be sent to the recovery of chrome, the same can
not be implemented, for obvious reasons, with the washing baths for large
volumes to process. Therefore, significant amounts of chrome escape from
recovery founding in wastewater and then in sewage sludge.
Moreover, recovery would result an economically disadvantageous operation
and difficult to carry out for end tanning baths with a limited concentration of
chrome.

3.2. OPTIMIZATION OF THE CHROME FIXATION
The improvement, within certain limits, of fixation and exhaustion of chrome, is
the system of more easily applicable reduction of chrome in wastewater.
Unlike the methods with a too forced exhaustion, the systems that are based
on this concept, do not interfere with the quality of some high level items.
The optimization of the chrome fixation does not require additional equipment
and can be obtained without being different from the normal processing
methods. In addition, the articles produced have a quality comparable to that
obtained with the standard methods for chrome tanning.

Any tanning optimization system must ensure to leather the same amount of
Cr2O3 of the standard working, ranging from a minimum of 3.5 to a maximum
of 4.2% (at 0% of humidity) and a shrinkage temperature above 100 °C.

The main parameters that influence the efficiency of fixation are as follows:

Amount of chromium salt (in Cr2O3)

A smaller amount of chrome is adequate if upholstery leather are produced,
while the higher one is required when leather for shoes is made.
The use of excessive amounts of chromium is not recommended, since it would
only increase the concentration of tanning agents and of suspended solids in
water discharged.
At the same time the quality of the article is not improved, while the costs of
production increase and sometimes the mechanical strength of the skin gets
worse.

Float, long

The efficiency of the pickel bath changes depending on the fact that chrome is
liquid, or in powder, because during tanning process it’s necessary to have
more or less the same volume of bath. In the first case, the pickel is made with
20‐25% water, in the second case with 30‐35%. The short float ensures a faster
penetration of chrome, a rapid rise in temperature, which allows to take
advantage of the thermal effect for a longer period of time.

Final temperature of tanning

10

This parameter is very important for the performance of fixation. It’s obvious that
a final temperature of 40°C ensures a good return on fixation without modifying
the characteristics of grain and mechanical strength.

Duration of tanning

The fixed quantity of chrome increases according to the duration of the process. It
is therefore recommended, as an indication, that the duration is not less than 10
hours from the time of chrome addition.

pH of the end tanning

The pH of the end tanning should be between 3.8 and 4.0 for upholstery leather.
For footwear articles it’s recommended not to exceed a value of 3.9. The size of pH
should be made by reliable and accurate instruments. To have a pH value of the
end tanning constant, deliming and pickel phases should be standardized.
As for temperature, if the desired pH value is reached in a reasonable timescale,
chromium can unfold its optimum responsiveness for a longer duration and,
consequently, increase the efficiency of fixation.

Masking

Masking agents, besides facilitating the penetration of chromium, making it more
stable to precipitation with alkali and giving leather blue‐tinted shades and a finer
grain, can swell the molecule of tanning.
This means that the reticular complex of chromium can more easily and
consequently improve the efficiency of fixation and of exhaustion of the float.

CONCLUSION
By optimizing the above listed parameters according to the recommended guidelines the
overall depletion of chrome can be greatly improved. Furthermore, they could reduce the
concentration of tanning agent in wastewater of the whole cycle of over 80 mg/l ¹

¹ Calculated assuming the use for each kilogram of raw skin of 25 liters of water for a complete processing cycle, an
average content of 3000 mg/l of sulfates of 7000 mg/l of chloride and 200 mg/l Cr in the effluent at the end of the
process.

11


Courtesy

ACQUE DEL CHIAMPO SPA MEDIO CHIAMPO SPA AVS
Via Ferraretta, 20 Via Gen. Vaccari, 18 Alto Vicentino servizi spa
36071 Arzignano (VI) 36054 Montebello Vic.no (VI) Via San Giovanni Bosco, 77/b
tel. +39‐0444 159 111 tel. +39‐0444 648 398 36016 Thiene (VI)
fax +39‐0444 459 222 fax +39‐0444 440 131 info@altovicentinoservizi.it
www.acquedelchiampospa.it www.mediochiampo.it
info@acquedelcahiampospa.it info@mediochiampo.it

Translation and Reprint by ASSOMAC SERVIZI S.r.l.

12

www.fertilandia.eu

fert ilandia

ENGLISH VERSION

www.fertilandia.eu

contacts presentation
CONSORZIO CUOIO-DEPUR S.P.A.
The main Objective of the project FERTILANDIA
Via Arginale Ovest, 81
56020 San Romano is to commercialize an Organic Nitrogenous
San Miniato (PI) | Italy Fertilizer named “pellicino integrato” (integrated
0571 44871 | 0571 450538 leather meal) constituted of a mix of leather
info@cuoidepur.it meal and dewatered sludge rising from tannery
www.cuoiodepur.it wastewater treatment plant. The specific object
of the action to be carried out is replacing the
CCT animal meals component - at present used in
Via Chico Mendez the prototype mix, with leather meal to obtain
56024 Ponte a Egola
C.C.T. srl an Organic Nitrogenous Fertilizers, to be used in
San Miniato (PI) | Italy
agriculture
GOZO COTTAGE
Gozitano Buildings
Mgarr Road Xewkjia
Gozo | Malta
info@gozocottage.com
www.gozocottage.com

The Fertilandia project is co-financed by the Eco-innovation programme
of the European Commission. The Eco-innovation programme supports
innovative solutions protecting the environment, supporting market
replication projects of products, processes or eco-innovative practices,
already technically proven, but needing incentives to have success in the
market.

Further information at ec.europa.eu/environment/eco-innovation/

www.fertilandia.eu

Before the Fertilandia project was
realised, the leather processing cycle
in the tannery district was carried out
before fertilandia ...
as follows:

tanneries
The slaughtering of animals for the
preparation of meat results in a by-
product made of coat and raw skins,
which cannot be used for the food
industry, but constituting the raw
material for the production of leather
in the tannery district of Ponte a
Egola. The tanning district located in
Tuscany between Florence and Pisa,
is characterised by the use of natural
agents such as tannins. 100 kg of raw
skins result in 30 kg of end product, 70
kg of by-products and 1,500-2,000 litres
of waste waters containing portions WASTE
cuoiodepur
disposal
of organic substance. Such organic DISPOSAL
substance derives from parts of skins,
cuttings, etc. The leather is used by At the Cuio Depur plant, waste water
the shoe and leather industry and it Solid by-products include all the is collected and treated, resulting in
supplies 95% of the Italian market for parts of the original skins not used for purified water, which is poured into
footwear soles and 60% of the European manufacture and to be sorted. the final receptor (the river Arno),
one. and sludge containing part of the
aforementioned by-products.

www.fertilandia.eu

after fertilandia...
The Fertilandia project makes
it possible to use by-products
that would otherwise be
sorted to be transformed into a
reusable resource.

tanneries
The slaughtering of animals for the
preparation of meat results in a by- cct
product made of coat and raw skins, With the creation of Consorzio CCT
which cannot be used for the food the current by-products of the tanning
industry, but constituting the raw process will be managed differently.
material for the production of leather Treated and untreated solid by-products
in the tannery district of Ponte a Egola. will be sent to the CTT plant to obtain
The tanning district is characterised
by the use of natural agents such as cuoiodepur organic flours with fertilising properties
to be mixed with the stabilised proteic
tannins. 100 kg of raw skins result in At the Cuio Depur plant, waste water
sludge received from Cuoio Depur.
30 kg of end product, 70 kg of by- is collected and treated, resulting in
The objective is producing a pelletted
products and 1,500-2,000 litres of waste purified water, which is poured into
nitrogenous organic fertilizer (the
waters containing portions of organic the final receptor (the river Arno),
integrated leather meal and the
substance. and sludge containing part of the
products derived from it), and is so
aforementioned by-products.
doing closing the chain.

www.fertilandia.eu

functioning
integrated leather meal

prodotto
The thus-obtained fertilizer, of full
organic origin, can easily be used
gozo cottage integra
te

to nourish plants. The balanced In the framework of the Fertilandia
composition guarantees that project, the integrated leather meal will
nutrients are properly released, with a be tested in Italy and in Gozo, Malta, by
conditioning effect. Gozo Cottage.

www.fertilandia.eu

product
Integrated leather meal is a nitrogenous fertilizer with high content of digestible organic matter. It is designed to replace most
common chemical fertilizers as ammonium nitrate, ammonium sulphate and urea.
A massive use of chemical fertilizers causes the loss of organic substances in the soil with the increase of erosive phenomena
and groundwater pollution of nitrogenous compounds.
Organic substances in soil have the role of:

- strengthening soil structure with colloidal and fibrous substances
- stabilising the aggregates
- increasing cationic exchange capacity
- increasing water hold up
- being a reserve of nutritious for micro organisms and soil’s fauna

It was estimated that over hundred years the utilisation of “compost”, similar in composition with integrated leather meal,
will consent to reduce 54 Kg of equivalent CO2 per ton of utilized compost (EC Environment DG, 2003). The use of organic
fertilizers in agriculture could therefore contribute in reducing carbon presence and air pollution. The disposal of sludge and
bio-waste produces a pollutant leachete and biogas.

The recycling of sludge and solid waste material from tanneries as integrated leather meal will not only contribute in reducing
greenhouse emission, but also to return organic substance to the soil.

An amount of 26.000 ton/year of sludge (the total production of Cuoio-Depur wastewater plant) can be reused in the
production of integrated leather meal and an amount of 12.000 ton/year of solid waste from tanneries will be processed to
obtain the leather meal, allowing a remarkable reduction of greenhouse emission, leachete, soil pollution and increasing
organic presence in soil.

Papers published in the Journal of the American Leather Chemists Association
(2008; 103(1): 1-6)

Life Cycle Assessment (LCA) of the oxidative unhairing process by hydrogen
peroxide

Domenico CASTIELLO(1), Monica PUCCINI(2), Maurizia SEGGIANI(2), Sandra VITOLO(2),
Francesco ZAMMORI(3)

(1) Po.Te.Co. Scrl – Polo Tecnologico Conciario Via Walter Tobagi, 30 - 56022 Castelfranco di Sotto Pisa, Italy
(2) Dipartimento di Ingegneria Chimica, Chimica Industriale e Scienza dei Materiali - Università di Pisa, Largo Lucio
Lazzarino, 1 - 56126 Pisa, Italy
(3) Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione - Università di Pisa, Via Bonanno Pisano, 25/B
56126 Pisa (Italy)

Abstract
The ever increasing attention to the environmental impact of the process industry imposes an
obligation to constantly improve the global sustainability of the tanning process.
Among the numerous phases of the tanning process, the beamhouse accounts for most of the total
polluting charge, due to the use of sodium sulfide and lime during the manufacturing process of
hides. Hence, the authors have recently developed an alternative unhairing process that eliminates
the use of sulfides. The actual reduction of the environmental impact of this process, in relation with
the traditional one, was evaluated performing a Life Cycle Assesment (LCA) using SimaPro 6, one
of the most used software for LCA analysis. Environmental impacts were finally rated using “EDIP
97” assessing methodology. Since impact assessment methodologies were mainly developed for the
manufacturing field, EDIP 97 was slightly modified and adapted to fit with the tannery industry.

Key words: LCA, unhairing process, sulfide, hydrogen peroxide

1

Introduction
The tanning industry generates great amount of wastes and causes several negative effects on the
ecosystem. Considering the ever increasing attention toward environmental themes, it is necessary
to minimize the pollution charge of effluents and to decrease production of wastes.
Among the several phases of the tanning process, the beamhouse is responsible for most of the
overall impact, as it generates 83% of BOD5, 73% of COD, 60% of suspended solids, 68% of
salinity and 76% of total polluting charge produced during the manufacturing process of hides. This
is because the traditional unhairing process requires sodium sulfide, and lime in the beamhouse
phase. Besides, the fleshing operation that follows the unhairing phase, generates a waste (mainly
constituted by collagen) whose reutilization and valorization, as a valuable protein source, may be
precluded by the presence of sulfides. Consequently, the development of an alternative unhairing
process, with an environmental impact lower than the traditional one, represents a priority. To the
scope, a recent research activity has been conducted by the authors (S. Bronco et al., 2005). The
obtained alterative unhairing process is based on the use of hydrogen peroxide and makes it
possible to avoid sulfides utilization. To assess the quality of the finished leather (obtained through
the oxidative unhairing process), several experimental activities have been performed, both on a
laboratory and on an industrial scale. Results have shown that the finished leathers are comparable
to that obtained by the traditional process in terms of physical-mechanical and technical properties.
In addition, the process has proved to be practical and economical to be implemented, for it is
compatible with the existing machineries installed in the plant.
Given the technical and the economical feasibility of the oxidative unhairing process, the objective
of the present work consists in the evaluation of the actual reduction of the environmental impact in
relation with the traditional one. To the scope, a Life Cycle Assesment (LCA) was made.
LCA is a methodology that provides a quantitative basis to assess the environmental performance of
a product and/or a process. The most important applications are: (i) analysis of the contribution of
the life stages to the overall environmental load, and (ii) comparison of products and/or processes
designed to fulfill the same function. First applications of LCA took place in the early nineties and
nowadays, LCA studies are receiving an increasingly deal of attention, especially to compare
products such as: paper/ceramic/plastic cup, polyetilene/cardboard packages, plastic/mirror bottles,
paper/cloth diapers, paper/plastic/durable shopping bags (Matthews et al., 2002). Other typical
applications concern the agri-food industry, and the energy production field. Excellent applications
can be found in: Andersson et al. (1993), Koroneos et al. (2003), Ardente et al. (2005), Finnveded
et al. (2005). On the contrary, fewer applications directly address chemical processes (Munoz et al.,
2006), and the tanning process in particular (Rius et al. 2002).
In the present work, the oxidative unhairing process is compared to the traditional one focusing in
particular on the life cycle stages that account for most of the environmental loads: (i) Na2S
production, (ii) H2S production, (iii) H2S waste treatment, (iv) unhairing. LCA was accomplished
by aim of SimaPro 6, one of the most used software for life cycle analysis in the industrial field.
Environmental impacts were finally rated using EDIP 97 assessing methodology. Since impact
assessment methodologies were mainly developed for the manufacturing field, EDIP 97 was
slightly modified and adapted to fit with the requirements of the tannery industry.

LCA Description
LCA is a quantitative and objective technique for assessing the environmental performance of a
product and/or a process over its life cycle (Werzel et al. 2000). The basic concept is that the impact
an item has on the environment does not depend exclusively on the manufacturing process, but
begins with the design and ends with the final disposal (Zabaniotou, Kassidi, 2002). For this reason,
all the inputs (i.e. energy, material, etc.) and the outputs (i.e. products, waste materials, emissions,
etc.) must be identified and quantified for each life stage of a product. Only in this way it is possible
to objectively evaluate its impact on the environment. According to the definition given in the
international standard ISO 1400, LCA is based on four sequential steps. These are listed below:
Aim and Scope definition (ISO 14040). The aim is a brief description of the reasons for using LCA,
while the scope is a clear definition of the main choices, assumptions and limitation of the analysis.

2

The main issues to be addresses are the following ones. Functional unit that is the reference
quantity used to evaluate, in relative terms, two alternative products. To keep the comparison fair
the functional unit should refer to the function fulfilled by each product. System boundaries that
specify which unit processes (i.e. life stages) are included in the analysis. Three alternative
approaches are possible: (i) first order (i.e. only production and transportation of material are
considered), (ii) second order (i.e. all process are included, but equipments and ancillary goods are
not considered), (iii) third order (i.e. also equipment are taken into account). Allocation rules are
used whenever a process realizes more than an output, or performs more than a function. Under
these circumstance it must be defined how the environmental loads of a process are allocated
among its several outputs.
Life Cycle Inventory (ISO 14041). During LCI, a model is made to represent the technical system
used to produce, transport, use and dispose of a product. This results in a flow diagram containing
all the unit processes of the entire life cycle. Furthermore, for each unit process, all the inflows and
outflows must be quantified (on a volume or mass basis) and listed into different environmental
categories, relevant to resource use, human health and ecological areas.
Life Cycle Impact Assessment (ISO 14042). To determine which flows are significant and how great
is their contribution, data contained in the LCI must be interpreted. To do that, a model of
environmental mechanisms is used to establish a connection between the environmental loading and
known exposure pathways to humans and ecology. Using several environmental mechanisms, LCI
results can be translated in a number of environmental issues of concerns (i.e. impact categories)
such as: acidification, ozone depletion, climate change, eutrophication etc.. The contribution of a
parameter to a certain impact category is then evaluate through an equivalence factor that expresses
its effects in relation with a reference parameter. For example CO2 is the reference parameter for the
“climate change” category and the equivalence factor for CH4 is 42 (i.e. contribution of 1 Nm3 of
CH4 is 42 times as high as the emission of 1 Nm3 of CO2). Clearly, determination of equivalence
factors is the most difficult and controversial step of the process, but can be often overcome
applying standard procedures (CML2, EDIP, ECO-Indicator) purposely developed to the scope.
Results are finally normalized to describes their magnitude in relation to a background impact that
is generally expressed as the average impact per person.
Interpretation and improvements (ISO 14043). The last step mainly consists in the validation of the
obtained results and in the development of feasible solutions intended to reduce the overall impact.

Methodology
Considering that the objective of the present work consists in an environmental comparison of two
alternative processes, LCA have been accomplished in relative terms using a third order approach,
and considering only inputs and outputs that change with the alternative. This is clearly represented
in Figure 1 that shows the main phases considered in the analysis.

Figure 1. Processes flow diagram

3

For what concerns the leather productive process, the main differences can be found in the inputs
required at the unhairing stage. On the contrary, energy flows, required machineries and ancillary
goods remain unchanged. Another major difference is due to the fact that the traditional process
requires a system to eliminate H2S generated during the unhairing process, while this step is
completely eliminated through the adoption of the oxidative process that uses oxygen peroxide
instead of sodium sulfide. Please note that the boundary of the system here considered includes the
production of chemicals used for the unhairing process. In fact, accordingly to the main principles
of LCA, all the environmental impacts occurring during the life cycle of an item must be taken into
account. If this was not made, the comparison would not be made on an equal base because
environmental loads upstream the unhairing process would be neglected.
This is especially true in the present case. In fact, if the boundary was not extended to include the
production of chemicals, the impact of the oxidative process would obviously results lower than the
traditional one, for the absence of sulfides in the wastewater and in the emissions.
Input flows and emissions at the unhairing phase were collected directly on the field, and are listed
in Table I. Please note that the amount of each pollutant is evaluated per kg of salted hides that
represents the functional unit adopted for the present work.

Oxidative Unhairing Traditional Unhairing
Na2S 0 [kg] 0.04 [kg]
Ca(OH)2 0 [kg] 0.04 [kg]
Input
NaOH (50%) 0.096 [kg] 0 [kg]
H2O2 0.09 [kg] 0 [kg]
COD 85.9 [kg] 106 [kg]
suspended solids 58.73 [kg] 59.9 [kg]
Output
Nitrogen (as NH4+) 0.8 [kg] 0.6 [kg]
Sulfides (as S2-) 0 [kg] 0.04 [kg]

Table I. Input – Output of the unhairing processes

Other data were taken from the Buwal and the Ecoinvent Database, both included in the library of
the software SimaPro 6, which has been used to develop the LCA model. This is clearly shown in
Figure 2, which displays the life cycle of the traditional unhairing process, defined in SimaPro 6.

Traditional
process

Traditional H2S
unhairing treatment

Na2S Ca(OH)2 NaOH Electricity

NaOH H2S Electricity Heatcoal

Figure 2. Life cycle of the traditional unhairing

4

In order to evaluate the environmental impact of both processes, taking into account the effect on
the ecosystem and on the human health, the following impact categories have been considered: (i)
global warning, (ii) ozone depletion, (iii) acidification, (iv) eutrophication, (v) photochemical smog,
(vi) eco-toxicity water chronic, (vii) eco-toxicity water acute, (viii) eco-toxicity soil chronic, (ix)
human toxicity air, (x) human toxicity water, (xi) human toxicity soil, (xii) bulk waste, (xiii)
hazardous waste, (xiv) radioactive waste, (xv) slag and ashes, (xvi) non renewable resources.
Next, to evaluate contributions to each environmental issues of concern, EDIP 97 impact
assessment methodology was selected. This choice was motivated by the fact that EDIP 97 is
probably the impact assessment methodology more suitable for an application concerning a
chemical process. In particular there is a perfect matching between the parameters for which EDIP
97 provides an equivalence factor, and the chemicals included in the LCI of the unhairing process.
The only inconvenient was that, unfortunately, EDIP 97 in its standard way, does not take into
account COD as parameters affecting the eutrophication impact category. However, COD is one of
the main parameter used to characterize wastewaters of a chemical process, as the one here
considered. To fulfill these requirements, a specific equivalence factor was computed in order to
express the environmental load of COD in relation to the reference parameter (i.e. nitrates). The
equivalence factor was evaluated in 0.23 point, making an interpolation of all parameters that
characterize the eutrophication impact category in EDIP 97 and CML’96 impact assessment
methodologies.

Results
Results of the impact assessment step are graphically shown in Figure 3 and Figure 4.
The bar chart of Figure 3 shows the relative contribution of the inputs of the traditional unhairing
process for each environmental impact category. It is evident that the life cycle of Na2S accounts for
most of the whole environmental impact. Therefore the elimination of Na2S from the unhairing
process appears to be necessary to reduce the environmental impact. Please note that the
environmental impact of Na2S is due to the sulfides released in the wastewaters and also to its
productive process.

Figure 3. Relative contribution of the inputs of the traditional unhairing process

The analogous evaluation for the oxidative unhairing process is shown in Figure 4, that shows how
the life cycle of H2O2 accounts for most of the whole environmental impact..

5

Human Tox. air

Bulk waste
Ecotox. Water ch.

Ecotox. Water ac.

Hazardous waste
Ozon depletion

Photoch. smog

Human Tox. water

Radioactive waste
Ecotox. Soil ch.

Slag - ashes
Human Tox. soil
Global Warming

Acidification

Eutrophication

Non Ren. Resourc.
Figure 4. Relative contribution of the inputs of the oxidative unhairing process

Finally, Figure 5 shows, in relative term, which one of the alternative processes has the greatest
impact for each impact category.

100%

80%

60%

40%
Oxidative unhairing
20% Traditional Unhairing

0%
Non Ren. Resourc.
Human Tox. water

Radioactive waste
Global Warming

Ecotox. Water ch.

Ecotox. Water ac.

Hazardous waste
Ozon depletion

Photoch. smog

Human Tox. soil
Eutrophication

Ecotox. Soil ch.

Human Tox. air
Acidification

Slag - ashes
Bulk waste

Figure 5. Impact assessment results

Take for instance the photochemical smog category. In this case, the oxidative process has an
impact 0.9 times lower than the traditional one. As can be seen from Figure 5, the oxidative
unhairing has an environmental impact greater than the traditional one in several impact categories.
This is due to the production of oxygen peroxide that accounts for more than the 50% of the overall
environmental impact.
As previously noted, for a fair assessment of results, data must be normalized to express their actual
magnitude in relation to a known reference value that is the equivalent impact per person (i.e. the
average annual impact generated by the ordinary activities performed by an individual).
Normalized data are listed in Table II.
As clearly shown in Table II, the impacts categories most significantly affected are “Eco – Toxicity
water chronic” and “Eco Toxicity water acute”. It is also evident that the adoption of the oxidative
process makes it possible to greatly reduce impact in both these environmental impact categories.

6

As far as the other categories are concerned, even if several impacts of the oxidative unhairing are
greater than the traditional one, their normalized magnitudes may be considered not significant in
terms of effects on the ecosystem and on the human health.

Impact Categories Oxidative Unhairing Traditional Unhairing

Global warming 1,96E-05 1,43E-05
Ozone depletion 1,08E-07 3,65E-07
Acidification 9,73E-06 8,80E-06
Eutrophication 9,32E-03 6,90E-03
Photochemical smog 7,12E-06 7,69E-06
Eco-toxicity water chronic 3,73E-04 7,00E+01
Eco-toxicity water acute 3,68E-04 3,36E+02
Eco-toxicity soil chronic 6,11E-05 4,34E-06
Human toxicity air 2,46E-06 1,29E-06
Human toxicity water 3,11E-05 3,49E-04
Human toxicity soil 4,77E-05 2,44E-05
Bulk waste 7,91E-06 3,44E-06
Hazardous waste 1,68E-07 1,43E-09
Radioactive waste 1,27E-04 4,78E-06
Slag/ashes 4,38E-06 7,01E-10
Non Renewable Resources 1,00E-08 1,00E-08

Table II Normalized results per impact category

Conclusions
An alternative oxidative unhairing process has been previously developed by the authors. Given its
technical and economical feasibility, the objective of the present work consists in the evaluation of
the reduction of the environmental load, in relation with the traditional process.
To assess the environmental sustainability, LCA was used to compare the traditional and the
oxidative unhairing process. The life cycle model for both processes has been implemented using the
software SimaPro 6. Results show that “Ecotoxicity water chronic” and “Ecotoxicity water acute”
are the most affected impact categories and that, damages on both these impact categories are greatly
reduced through the adoption or the oxidative unhairing process.
At the moment, the process has been investigated leaving the wastewaters treatment out of the
boundaries of the system. Considering the obtained results, which reveal that the main impact affect
the water’s pollution, it seems desirable to extend the systems boundaries to include in the analysis
the treatment of the wastewaters too. Further researches are intended to the scope.

7

Bibliography

Andersson, K.,Ohlsson, T., and Olsson, P., (1993), Life Cycle Assessment of food products and
production systems, Part 1: LCA methodology, a literature review. SIK – Report 599:I, Swedish
Institute for Food and Biotechnology.
Ardente, F., Beccali, G., Cellura, M., Lo Brano, V., (2005), Life Cycle Assessment of solar
thermal collector, Renewable Energy, Vol. 30, pp. 1031-1054.
Bronco, S.,Castiello, D., D’Elia, G., Salvadori, M., Seggiani, M., Vitolo, S., (2005), Oxidative
Unhairing with Hydrogen Peroxide: Development of an Industrial Scale Process for High-Quality
Upper Leather, JALCA, Vol.100, pp. 45-53.
Koroneos, C., Roumbas, G., Gabari, Z., Papagianniodou, E., and Moussiopoulos, N., (2003), Life
cycle assessment of beer production in Greece, Journal of Cleaner Production, Vol. 13, pp. 433-
439.
Finnveded, G., Johansson, J., Lind, P., Moberg, A., (2005), Life cycle assessment of energy from
solid waste, Journal of Cleaner Production, Vol. 13, pp
Matthews, H., S., Lave, L.,Maclean, H., (2002), Life Cycle Impact Assessment: A Challenge for
Risk Analysts, Risk Analysis, Vol. 22, N. 5, pp. 853-860.
Munoz, I., Rieradevall, J., Torrades, F., Peral, J., Domenech, X., (2006), Environmental
assessment of different advanced oxidation process applied to a bleaching Kraft mill effluent,
Chemosphere, Vol. 62, pp. 9-16.
Rius, A., Hidalgo, R., Canela, J. M., Milà, L., Domènech, X., Rieradevall, J., and Fullana, P.,
(2001), Use of LCA for the comparison of different strategies in the tanning process, Setac
Europe.
Wenzel, H., Hauschild, M. Z., Alting, L., (2000), Environmental assessment of products, volume
1: Methodology, Tools and Case Studies in Product Development, Springer.
Zabaniotou, A., Kassidi,E., (2003), Life cycle assessment applied to egg packaging made from
polystyrene and recycled paper, Journal of Cleaner Production, Vol.11, pp. 549-559.

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