Eylem KILI Eylem 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
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endend--------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 treatment
tannery sludge treatmenttannery sludge treatment tannery sludge treatment tannery sludge treatment tannery sludge treatmenttannery sludge treatment tannery 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 sludge disposal of chromium containing sludge disposal of chromium containing sludge disposal of chromium containing sludge disposal of chromium containing sludge disposal of chromium containing sludge disposal of chromium containing sludge disposal 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
sludge sludge sludge sludge sludge sludge sludge sludge
Basic Chromium
Sulfate Tannery sludge
Treated sludge
2952mgCr/kg sludge 8041mgCr/kg sludge
H2O2
Decomposition Chromium
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 process recovery process recovery process recovery process recovery process recovery processrecovery process recovery 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 boundaries System boundaries Life cycle inventory Life cycle inventory
Wastewater Treatment Plant Wastewater Treatment Plant
Composting plant &
Composting plant &
GaBi Database GaBi Database
Experimental studies
Experimental 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 assessment Impact assessment Impact assessment Impact assessment Impact assessment Impact assessmentImpact assessment Impact 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
-0,5 0 0,5 1 1,5 2 2,5 3 3,5 4
-0,2 0 0,2 0,4 0,6 0,8 1 1,2 1,4
-0,05 0 0,05 0,1 0,15 0,2 0,25 0,3 0,35 -0,5
0 0,5 1 1,5 2 2,5 3
-100 0 100 200 300 400 500 600 700 800 900 1000
-0,1 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9
-5 -4 -3 -2 -1 0 1 2 3 4
-5 0 5 10 15 20 25 30
-1,E-05 0,E+00 1,E-05 2,E-05 3,E-05 4,E-05 5,E-05 6,E-05 7,E-05 8,E-05
-10000 0 10000 20000 30000 40000 50000 60000 -1000
0 1000 2000 3000 4000 5000 6000 7000
WWTP Cr recovery
H2O2 decomposition Cr precipitation BCS production
Sludge drying&Landfilling
Environmental comparison between sludge and conventional treatme Environmental 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:
0 200 400 600 800 1000
GWP
0 0,5 1 1,5 2 2,5 3 3,5 4
ADP
0 0,05 0,1 0,15 0,2 0,25 0,3 0,35
POCP 0
0,5 1 1,5 2 2,5 3
AP
0 0,2 0,4 0,6 0,8 1
EP
-2 -1 0 1 2 3
FAETP
0 5 10 15 20 25 30
HTTP
0 10000 20000 30000 40000 50000 60000
MAETP
0,E+00 1,E-05 2,E-05 3,E-05 4,E-05 5,E-05 6,E-05 7,E-05 8,E-05
ODP
0 0,2 0,4 0,6 0,8 1 1,2 1,4
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 impact due to, material and energy use unless the treatment is simple and 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.
