Removal of metal ions from aqueous solution by adsorption onto activated carbon clothsadsorption com.pdf

Carbon 40 (2002) 2387–2392 R emoval of metal ions from aqueous solution by adsorption onto activated carbon cloths: adsorption competition with organic matter *C. Faur-Brasquet , K. Kadirvelu, P. Le Cloirec Ecole des Mines de Nantes, GEPEA, 4 Rue Alfred Kastler, BP 20 722, 44307 Nantes Cedex 03, France Received 24 July 2001; accepted 4 April 2002 Abstract Activated carbon cloths are recent adsorbents whose adsorption properties are well known for monocomponent solutions of organics or metal ions. However, to treat wastewaters with these materials, their performance has to be determined in 21 21 multicomponent solution. This work studies adsorption competition between metal ions (Cu , Pb ) and organic matter (benzoic acid). The first part investigates adsorption equilibrium of monocomponent metal ions solutions and shows the dependence of adsorption capacities on adsorbent porosity and metal ions chemical properties (molecular weight, ionic radius and electronegativity). The influence of pH is also demonstrated. The second part focuses on adsorption competition: (1) between both metal ions (a decrease of adsorption capacities is observed, whose value is related to adsorption kinetics of metal ions); (2) between metal ions and organic matter, in solution or adsorbed onto the activated carbon cloth (a strong influence of pH is shown: when benzoic acid is under benzoate form, in both cases adsorption is increased due to the formation of ligands between adsorbed benzoate ions and metals). ? 2002 Elsevier Science Ltd. All rights reserved. Keywords: A. Carbon fibers; Activated carbon; C. Adsorption; D. Adsorption properties 1 . Introduction Their performance for the removal of heavy metal ions was also studied in monocomponent solutions [9] but to The strong release of heavy metals into the environment aim at using these adsorbents to treat industrial waste- by several industries [1,2] has meant that their recovery waters, the competitive adsorption of organics and metals