• Sri Sunarsih Teknik Lingkungan, Institut Sains & Teknologi AKPRIND Yogyakarta
  • Sri Juari Santosa Jurusan Kimia, Universitas Gadjah Mada Yogyakarta
  • Mudasir - Jurusan Kimia, Universitas Gadjah Mada Yogyakarta.
Keywords: acidify, humic acid, speciation, humic acid water


The influences of acidify and humic acid (HA) weight on Cu(II) speciation in humic acid-water system has been studied. The HA was extracted from peatsoil in Siantan, Pontianak, West Kalimantan. The Cu(II) solution was made from Cu(SO)4.s H2O crystal of E.Merck for analytical grade. The acidify effect test carried out with 50 mL of Cu(II) solution in 100 ppm concentration then varied their pH level at 4, 5 ,6, 7 and 8. To each solution added with 30 mg of HA, be interacted in 1 hour, and then settled in 24 hour to be equilibrium. The same procedure were done to prepare the solutions for determining the effect of HA weight on Cu(II) speciation. The weight of HA varied at 20, 40, 60, 80 and 120 mg with pH solution 5,0. The concentration of total Cu and hydrated Cu(II) were determined using Atomic Absorption Spectrophotometer and Ionic Selective Electrode (ISE), respectively.  Based on measurement of total Cu and hydrated Cu known that if the initial pH of solution higher, the absorption of Cu to HA became higher too. The fraction that was not absorbed distributed as hydrated Cu and Cu-AH complex that their concentration was in equilibrium at pH value of 5,0. The result of pH measurement at the equilibrium, the value of Ksp Cu(OH)2  and calculation of OH- indicated that there were no deposition of Cu(OH)2 formed. The measurement also indicated that if the more weight of HA applied on the interaction, the absorption to Cu became higher. The fraction that was not adsorbed increasingly as Cu-AH complex.


Aster, B., Bohlen, A. and Burba, P., 1997, Determination of Metal and Their Species in Aquatic Humic Substances by Using Total- Reflection X-ray Fluorescence Spectrometry, Spect. chim. Act. Part B, 52 : 1009 -1018.
Caroli, S., 1996, Chemical Speciation: A Decade of Progress, Element Speciation in Bioinorganic Chemistry, John Wiley & Sons, Inc., Singapore,
Ebing, D.D. and Wrightton, M.S., 1987, General Chemistry, p 650, 2nd Edition, Hughton Miflin Company, Boston,
Jones, M.N. dan Bryan, N.D., 1998, Colloidal Propertis of Humic Substances, Adv.Colloidal Interfaces Sci,78 : 1- 48
Lorenzo, J.I., Nieto, O. dan Beiras, R., 2002, Effect of Humic Acid on Speciation and Toxicity of Copper to Paracentrotus lividus larvae in Seawater, Aquatic Toxicol., 58: 27 - 41
Lu, X.Q., and Johnson, W.D., 1997, The Reactions of Aquatic Humic Substances with Copper(II) ions: an ESR Study of Complexation, Sci. Total Environ., 203: 199 - 207.
Mota, A.M. and Goncalves,L.S., 1996, Direct Methods of Speciation of Heavy Metal in Natural Waters, Element Speciation in Bioinorganic Chemistry (Caroli,S), John Wiley & Sons, Inc., Singapore.
Plavsic, M., and Cosovic, B., 1999, Voltametric Study of the Role of Organic Acids on Sorption of Cd and Cu Ions by Alumina Particles, Colloids Surf. A ,151: 189 - 200
Sanjay, H.G., Fataftah, A.K., Walia, D.S. and Srivastava, K.V., 1999., Humasorb CSTM : A Humic Acid Based Adsorbent to Remove Organic and Inorganic Contaminants, in Understanding Humic Substances : Advanced methods, Properties and Applications, (E.A. Ghabbour and G. Davies) Royal Society of Chemistry, Cambridge, pp 241
Stevenson, F.J., 1985, Geochemistry of Soil Humic Substances, in Humic Subtances in Soil, Sedimen, and Water: Geochemistry,Isolation, and Characterization (G.R. Aiken, D.M. McKnight, R.L. Wershaw, P McCharthy Eds) John Wiley & Sons, New York, pp 35 -40.
Stevenson, F.J., 1994, Humic Chemistry : Genesis, Composition, Reactions, John Wiley & Sons Ltd, Toronto, pp 381-388.
Tan, K.H., 1998, Dasar-dasar Kimia Tanah, Gadjah Mada University Press, Yogyakarta.
Xia, K., Bleam W. and Helmke P.A.,, 1997, Studies of Nature of Binding Sites of First Row Transition Elements Bound to Aquatic and Soil Humic Substances using X-ray Absorption Spectroscopy, Geochim. Cosmochim. Acta, Vol 61,No11.