Metal sanayi atık çamurlarından ağır metal gideriminde farklı liç yöntemlerinin kullanılması

Bu çalışmada, metal sanayi atık çamurlarından ağır metal gideriminde asit liç, kimyasal liç ve tam karışımlı-kesikli reaktörde biyoliç yöntemleri kullanılmıştır. Uygulanan her bir yöntem için pH, katı yükleme oranı ve bekletme süresinin liç işlemi üzerine etkisi araştırılmıştır. Aynı zamanda, ağır metal çözünürlüklerine göre her bir yöntemin karşılaştırılması yapılmıştır. Uygulanan liç yöntemlerinde, pH’nın azalması ve bekletme süresinin uzamasıyla ağır metal çözünürlüğü artarken, katı yükleme oranının artmasıyla metal çözünürlüğü azalmıştır. Ağır metal çözünürlükleri; asit liç işleminde %73 Zn, %58 Cd, %60 Pb, %15 Cr, %70 Ni, %69 Cu, kimyasal liç işleminde %90 Zn, %70 Cd, %65 Pb, %25 Cr, %77 Ni, %85 Cu ve tam karışımlı-kesikli reaktörde yapılan biyoliç işleminde %97 Zn, %80 Cd, %85 Pb, %34 Cr, %93 Ni, %96 Cu olarak bulunmuştur. Her bir ağır metal için en yüksek reaksiyon hız katsayısı (k, gün-1) değerleri tam karışımlı-kesikli reaktörde yapılan biyoliç işleminde elde edilmiştir. Bu elde edilen k değerleri Zn, Cd, Pb, Cr, Ni ve Cu için sırasıyla 0,1734, 0,0595, 0,0832, 0,0214, 0,1267 ve 0,1762 gün-1 olarak tespit edilmiştir.

The use of different leaching methods to remove heavy metals from metal industry waste sludge

In this study, the methods of acid leaching, chemical leaching and bioleaching in completely-mixed batch reactor were used to remove heavy metals from a metal industry waste sludge. The effect of pH, solids loading rate and detention time on the leaching process were investigated. The percent solubility of heavy metals increased with a decrease in pH and solids loading rate and an increase in detention time for all leaching applications. The solubility of heavy metals were found as: 73% Zn, 58% Cd, 60% Pb, 15% Cr, 70% Ni, 69% Cu for acid leaching; 90% Zn, 70% Cd, 65% Pb, 25% Cr, 77% Ni, 85% Cu for chemical leaching; and 97% Zn, 80% Cd, 85% Pb, 34% Cr, 93% Ni, 96% Cu for the bioleaching in a completely-mixed bach reactor. The highest values of rate constant (k) (day-1) for the solubility of heavy metals obtained from the bioleaching experiments results were determined as 0,1734, 0,0595, 0,0832, 0,0214, 0,1267, 0,1762 day-1 for Zn, Cd, Pb, Cr, Ni and Cu respectively.

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  • 1.Sreekrishnan,T.R., Tyagi,R.D., “A Comparative Study of the Cost of Leaching Out Heavy Metals from Sewage Sludges”, Process Biochemistry, 31 (1): 31-41, 1996.
  • 2.Sreekrishnan,T.R., Tyagi,R.D., “Sensitivity of Metal Bioleaching Operation to Process Variables”, Process Biochemistry, 30 (1): 69-80, 1995.
  • 3.Fournier,D., Lemieux,R., Couillard,D., “Essential Interactions between Thiobacillus Ferooxidans and Heterotrophic Microorganisms during a Wastewater Sludge Bioleaching Process”, Environmental Pollution, 101: 303-309, 1998.
  • 4.Filali-Meknasi,Y., Tyagi,R.D., Narasiah,K.S., “Simultaneous Sewage Sludge Digestion and Metal Leaching: Effect of Aeration”, Process Biochemistry, 36: 263-273, 2000.
  • 5.Shanableh,A., Ginige,P., “Acidic Bioleaching of Heavy Metals from Sewage Sludge”, J. Mater Cycles Waste Management, 2: 43-50, 2000.
  • 6.Ito,A., Umita,T., Aizawa,J., Takachi,T., Morinaga,K., “Removal of Heavy Metals from Anaerobically Digested Sewage Sludge by a New Chemical Method Using Ferric Sulfate”, Wat. Res. 34 (3): 751-758, 2000.
  • 7.Lundgren,D.G., Valkova-Valchanova,M., Reed,R., “Chemical Reactions Important in Bioleaching and Bioaccumulation”, Biotechnology and Bioengineering Symp., 16. 7-21, 1986.
  • 8.Billiton, “Recent Bioleaching Developments: Creating Value Through Innovation Biotechnology in Mining”, 1-11, 2000.
  • 9.Poulin,R., Lawrence,R.W., “Economic and Environmental Niches of Biohydrometallurgy”, Minerals Engineering, 9 (8): 799-810, 1996.
  • 10.Epa Test Methods Evaluating Solid Waste, “Method 3050: Acid Digestion of Sediments, Sludge and Soils”, Volume IA: Laboratory Manual Physical/Chemical Methods, Office of Solid Waste and Emergency Response, U. S. Environmental Protection Agency, DC 20460, Washington, 1986.
  • 11.Standard Methods, “Standard Methods for the Examination of Water and Wastewater 20th Edition”, APHA, AWWA, WEF. ISBN 0-87553-235-7, 1998.
  • 12.Bojinova,D.Y., Velkova,R.G., “Bioleaching of Metals from Mineral Waste Product”, Acta Biotechnol, 21 (3): 275-282, 2001.
  • 13.Brombacher,C., Bachofen,R., Brandl,H., „Development of Laboratory-Scale Leaching Plant for Metal Extraction from Fly Ash by Thiobacillus Strains”, Applied and Environmental Microbiology, 64 (4): 1237-1241, 1998.
  • 14.Jenkins et al.(1981) from Ito,A., Umita,T., Aizawa,J., Takachi,T., Morinaga,K., “Removal of Heavy Metals from Anaerobically Digested Sewage Sludge by a New Chemical Method Using Ferric Sulfate”, Wat. Res. 34 (3): 751-758, 2000.
  • 15.Blais,J.F., Tyagi,R.D., Auclair,J.C., “Comparison of Acid and Microbial Leaching for Metal Removal from Municipal Sludge”, Water Sci. Tech. 12 (1-2): 197-206, (from Ito et al. (2000)), 1992.
  • 16.Seidel,H., Ondruschka,J., Morgenstern,P., Stottmeister,U., “Bioleaching of Heavy Metals from Contaminated Aquatic Sediments using Indigenous Sulfur Oxidizing Bacteria: A Feasibility Study”, Water Science and Technology, 23 (7): 123-131, 1998.
  • 17.Fowler,T.A., Holmes,P.R., Crundwell,F.K., “Mechanism of Pyrite Dissolution in the Presence of Thiobacillus ferrooxidans”, Applied and Environmental Microbiology, 65 (7): 2987-2993, 1999.
  • 18.Boon,M., Heijnen,J.J., “Chemical Oxidation Kinetics of Pyrite in Bioleaching Processes”, Hydrometallurgy, 48: 27-41, 1998.
  • 19.Veglio,F., Beolchini,F., Nardini,A., Toro,L., « Bioleaching of Pyyrhotite Ore by Sulfooxidans Strain: Kinetic Analysis”, Chemical Engineering Science, 55: 783-795, 2000.
  • 20.Das,T., Ayyappan,S., Chaudhury,G.R., “Factors Affecting Bioleaching Kinetics of Sulfide Ores Using Acidophilic Micro-Organisms”, BioMetals, 12: 1-10, 1999.
  • 21.Villar,L.D., Garcia,O.Jr., “Solubilization Profiles of Metal İons from Bioleaching of Sewage Sludge as a Function of pH. Biotechnology Letters”, 24: 611-614, 2002.
  • 22.Yahya,A., Johnson,D.B., “Bioleaching of Pyrite at Low pH and Low Redox Potentials by Novel Mesophilic Gram-positive Bacteria”, Hydrometallurgy, 35: 168-176, 2001.
  • 23.Shanableh,A., Ginige,P., “Impact of Metals Bioleaching on the Nutrient Value of Biological Nutrient Removal Biosolids”, Water Science and Technology, 39 (6): 175-181, 1999.
  • 24.Bosecker,K., “Bioleaching: Metal Solubilization by Microorganisms”, FEMS Microbiology Reviews, 20: 591-604, 1997.
  • 25.Gomez,C., Blazquez,M.L., Ballester,A., “Bioleaching of Spanish Complex Sulphide Ore Bulk Concentrate”, Minerals Engineering, 12 (1): 93-106, 1999.
  • 26.Chen,S.Y., Lin,J.G., “Bioleaching of Heavy Metals from Sediments: Significance of pH”, Chemosphere, 44: 1093-1102, 2001a.
  • 27.Chen,S.Y., Lin,J.G., “Influence of solid Content on Bioleaching of Heavy Metals from Contaminated Sediment by Thiobacillus spp”, Journal of Chemical Technology and Biotechnology, 75: 649-656, 2000.
  • 28.Picher,S., Drogui,P., Guay,R., Blais,J.F., “Wastewater Sludge and Pig Manure Used as Culture Media for Bioleaching of Metal Sulphides” Hydrometallurgy, 65: 177-186, 2002.
  • 29.Lizama,H.M., Fairweather,M.J., Dai,Z., Allegretto,T.D., “How does Bioleaching Start? Hydrometallurgy”, 69: 109-116, 2003.
  • 30.Chen,S.Y., Lin,J.G., “Effect of Substrate Concentration on Bioleaching of Metal-Contaminated Sediment”, Journal of Hazardous Materials, B82: 77-89, 2001b.