Title: Phosphate removal from wastewater using aluminium oxide as adsorbent

Authors: Weimin Xie, Qunhui Wang, Hongzhi Ma, Hiroaki Ogawa

Addresses: Department of Environmental Science and Engineering, Harbin Institute of Technology, 202 Haihe Road, Nagang, Harbin 150090, China. ' Department of Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian, Beijing 100083, China. ' Department of Environmental Science and Engineering, Harbin Institute of Technology, 202 Haihe Road, Nagang, Harbin 150090, China. ' Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan

Abstract: The development and manufacture of an adsorbent to remove phosphate for the prevention of eutrophication in lakes is very important. The use of aluminium oxide (alumina) as an organic adsorbent to remove phosphate from wastewater has been investigated. The characteristics of this absorption process were investigated to determine the important parameters, such as the pH and the aluminium ion concentration. Moreover, chemical treatment methods to enhance the adsorption capacity of alumina were tested. Dynamic studies and equilibrium adsorption isotherm studies were conducted to determine the adsorption capacity and efficiency. The experimental results indicate that it is necessary to increase the temperature above 500°C in order to obtain a high-capacity adsorbent, and alumina treated with acid or calcium or magnesium has a larger adsorption capacity for phosphate than untreated adsorbent. Moreover, the adsorption of phosphate was enhanced at a lower pH and a higher aluminium ion concentration, and a simple Freundlich isotherm could express the equilibrium adsorption isotherm, and the intragranular diffusion controlling model was used to test the dynamic studies. These findings have important implications for the application and development of aluminium oxide as a prospective adsorbent.

Keywords: aluminium oxide; adsorbents; equilibrium adsorption isotherm; phosphate removal; wastewater treatment; lake eutrophication; alumina.

DOI: 10.1504/IJEP.2005.007611

International Journal of Environment and Pollution, 2005 Vol.23 No.4, pp.486 - 491

Published online: 19 Aug 2005 *

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