Methylene blue and iodine adsorption onto an activated desert plant

Although frequently less toxic than many colorless effluents, colored effluents are generally considered by the public as an indicator of pollution. The present investigation aimed at identifying the effectiveness of a local desert plant characteristic of Southwest Algeria and known as Salsola vermiculata which was, pyrolyzed and treated chemically with a 50% zinc chloride solution, to remove methylene blue and iodine. The natural plant adsorption capacities were respectively 23 mg/g and 272 mg/g for methylene blue and iodine. Corresponding results for the pyrolyzed plant uptakes were 53 mg/g and 951 mg/g, while those for the pyrolyzed plant, chemically treated and activated at 650 degrees C, were 130 mg/g and 1178 mg/g, respectively. In comparison, the standard Merck activated carbon capacities were 200 mg/g for methylene blue and 950 mg/g for iodine. Consequently, this low-cost local plant may also prove useful for the removal of large organic molecules as well as potential inorganic contaminants. (c) 2008 Elsevier Ltd. All rights reserved.