ISSN 1063-455X, Journal of Water Chemistry and Technology, 2014, Vol. 36, No. 3, pp. 110–114. © Allerton Press, Inc., 2014. Original Russian Text © S.S. Stavitskaya, V.M. Vikarchuk, M.F. Kovtun, O.I. Poddubnaya, A.M. Puziy, 2014, published in Khimiya i Tekhnologiya Vody, 2014, Vol. 36, No. 3, pp. 203–210. 110 Adsorption of Copper Ions by Carbon Adsorbents Modified by Phosphoric Acid at Different Temperatures S. S. Stavitskaya, V. M. Vikarchuk, M. F. Kovtun, O. I. Poddubnaya, and A. M. Puziy* Institute of Sorption and Problems of Endoecology, NAS of Ukraine, Kiev *e-mail: alexander.puziy@ispe.kiev.ua Received April 3, 2013 Abstract—The article has investigated adsorption of copper ions by activated carbons from coconuts at different temperatures (400–900°C). Adsorption of copper ions was studied at different values of the pH and initial concentrations. It has been shown that an increase of temperature of modifying carbon results in a growth of the degree of copper extraction. It has also been detected that the presence of albumin in the solution does no affect the degree of copper extraction. DOI: 10.3103/S1063455X14030023 Keywords: adsorption of copper ions, concentration and the pH of solutions, temperature of heat treat- ment, carbons containing phosphorus. INTRODUCTION Owing to anthropogenic activity heavy metals contaminate the water environment and may be a cause of a number of diseases. Increased concentration of copper ions in drinking water may cause a disease of liver and digestive tract, disruption of the activity of the central nervous system. A healthy content of copper ions in drinking water recommended by the World Health Organization constitutes 2 mg/dm 3 [1]. Therefore, the removal of heavy metals from the water environment is an important scientific practical task. One of the most efficient methods of water treatment of heavy metals is adsorption on activated carbon. By means of sorption methods in addition to water conditioning one may do prophylactic and successful treatment of diseases caused by penetration into organism of heavy metals [2]. As is known, the presence of surface functional groups enhances the capacity of carbon adsorbents to absorb cations of metals from aqueous solutions [3, 4]. Earlier it was shown that modification of carbon adsor- bents by phosphorus compounds results in emergence of acidulous properties and an increase of adsorption capacity with respect to cations of metals [5, 6]. Phosphoric heteroatoms may be introduced to the carbon structure both by modifying carbon feedstock prior to carbonization [7–10] and as a ready carbon adsorbent [11]. The objective of the present paper, which is a continuation of research begun earlier [11] is the investigation of sorption properties with respect to copper ions from coconut (Aquacarb 607C, Chemviron) modified by phosphoric acid at different temperatures (400–900°C). For comparison carbon obtained by oxidation in a 25% solution of HNO 3 of the same initial coconut carbon (sample Ox) was used. EXPERIMENTAL The amount of phosphorus in carbon adsorbents was determined by means of a X-ray fluorescent analyzer Elvax (Ukraine). Adsorption of copper ions was investigated by the method of individual weighted amounts from aqueous solutions at different values of the pH and initial concentrations 50 and 500 mg/dm 3 against the background 0.1 M of NaNO 3. The ratio of solid and liquid phases constituted 1 : 200, contact time—24 h. The pH of equilibrium solutions was regulated by addition of 0.1 M HNO 3 and 0.1 M of NaOH in different amounts and were measured by means of a glass electrode on a EV-74 device. Initial and equilibrium concen- trations of copper ions were determined by the method of atomic–absorption spectroscopy on an AA-6300 device (Shimadzu, Japan). Results of adsorption of copper ions on coppers being investigated are represented in the form of relationship between the degree of extraction (A = 1– C/C 0 ) and the pH of equilibrium solu- tions. PHYSICAL CHEMISTRY OF WATER TREATMENT PROCESSES