Eylem KILIEylem KILIÇÇ

Usak University Leather Research Centre Usak University Leather Research Centre

17th SETAC Europe LCA Case Studies Symposium

28 February-1 March 2011

Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of Use of LCA for the environmental evaluation of

endendendendendendendend--------ofofofofofofofof--------pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on pipe processes: a case study on

tannery sludge treatmenttannery sludge treatmenttannery sludge treatmenttannery sludge treatmenttannery sludge treatmenttannery sludge treatmenttannery sludge treatmenttannery sludge treatment

Problem: Problem: Problem: Problem: Problem: Problem: Problem: Problem:

� Basic chromium sulfate (BCS) is the most widely used tanning agent in leather industry. But only 54-57% of the chromium reacts with the hides and skin.

� Cr(III) is less toxic and soluble according to Cr(VI); however under certain circumstances Cr(III) maybe oxidized to Cr(VI)

� Landfilling of these wastes is loss of potential resource in the form of “chromium”.

Environmental contamination due to Environmental contamination due to Environmental contamination due to Environmental contamination due to Environmental contamination due to Environmental contamination due to Environmental contamination due to Environmental contamination due to

disposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludgedisposal of chromium containing sludge

Solution:Solution:Solution:Solution:Solution:Solution:Solution:Solution:

� Recovery of chromium from tannery sludge in order to reduce:� Chromium discharged

� Raw chromium extracted from nature

� Evaluation of the environmental impacts of the chromium recovery process in comparison with the conventional landfilling performing a Life Cycle Assessment (LCA) using GaBi software

SLUDGE TREATMENT

Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery Recovery of chromium from tannery

sludgesludgesludgesludgesludgesludgesludgesludge

Basic Chromium Sulfate

Tannery sludge

Treated sludge

2952mgCr/kg sludge

8041mgCr/kg sludge

H2O2

DecompositionChromium Recovery

Chromium Precipitation

� Recovery yield 70%

� Cheap chemical (H2O2)

� Nontoxic reaction product

Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium Environmental evaluation of chromium

recovery processrecovery processrecovery processrecovery processrecovery processrecovery processrecovery processrecovery process

� LCA METHODOLOGY

� Goal of the study: to identify the environmental impacts of chromium recovery from sludge prior to landfilling compared to the conventional direct landfilling.

� Functional unit: treatment of 100 m3 of wastewater

� System under study:

� Conventional System

� Sludge Treatment System

System boundariesSystem boundariesLife cycle inventoryLife cycle inventoryWastewater Treatment PlantWastewater Treatment Plant

Composting plant & Composting plant & GaBi DatabaseGaBi Database

Experimental studiesExperimental studies Industrial plant Industrial plant

100 m3

16.4 kg

� CML 2001 impact assessment methodology

� Quantification and evaluation of the environmental impacts of both systems were performed by analyzing:

� Energy Consumption (EC)� Abiotic Depletion Potential (ADP)� Acidification Potential (AP) � Eutrophication Potential (EP) � Freshwater Aquatic Ecotoxicity Potential (FAETP)� Global Warming Potential (GWP)� Human Toxicity Potential (HTP)� Marine Aquatic Ecotoxicity Potential (MAETP)� Ozone Layer Depletion Potential (ODP) � Photochemical Ozone Creation Potential (POCP) � Terrestrial Ecotoxicity Potential (TETP) impact categories.

Impact assessmentImpact assessmentImpact assessmentImpact assessmentImpact assessmentImpact assessmentImpact assessmentImpact assessment

Results and Results and Results and Results and Results and Results and Results and Results and interpretationinterpretationinterpretationinterpretationinterpretationinterpretationinterpretationinterpretation�� Environmental evaluation of sludge treatmentEnvironmental evaluation of sludge treatment

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WWTP

Cr recovery

H2O2 decomposition

Cr precipitation

BCS production

Sludge drying&Landfilling

Environmental comparison between sludge and conventional treatmeEnvironmental comparison between sludge and conventional treatmentnt

Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:Reduction of environmental impacts achievable by:

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ODP

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TETP

Conventional treatment

Sludge treatment

Chromium recovery using 50% less process water

Chromium recovery using byproduct

Chromium recovery using byproduct and 50% less process water

Sludge treatment with anaerobic digestion

�reduction of water consumption (50%)

�use of by-products�anaerobic digestion

Conclusion Conclusion Conclusion Conclusion Conclusion Conclusion Conclusion Conclusion

� The end-of-pipe treatments increase the environmental impactdue to, material and energy use unless the treatment is simpleand recovers a significant amount of waste.

� More efficient chromium recovery process can be achieved by “anaerobic or aerobic digestion of sludge”

� The results can serve as a basis to improve the chromium recovery and tannery sludge management options and should be used in decision-making processes especially for end-of-pipe treatments.

Thank you for your

kind attention…