Study of the Adsorption of Methylene Blue from Aqueous Solution: a Comparison between Iraqi & English bentonite Activity as Adsorbents ٕض٘لكًلإاّ ٖلاشعلا ذٗبًْزٌجلا ي٘ط خ٘لبعف ي٘ث خًسبمه :خ٘ئبولا ل٘لبؾولا يه ي٘ل٘ضولا قسصا خغجص صاضزها خعاسد حصبه داْوك

Background: Methylene blue dye uses as adsorbent to study the ability of different surface activities as adsorbents. The adsorbents can be used in the extraction of certain pollutant substances from solution on solids which is one of the cheapest and easiest separation methods. Furthermore, some of the extracted substances are economically important. In previous work, the ability of English bentonite to extract methylene blue dye from aqueous solution was carried out. In this work, Iraqi locally bentonite was used as a cheaper adsorbent for methylene blue from aqueous solution. The second aim of the present study is to make a comparison between English bentonite and Iraqi bentonite in different parameters of adsorption of Methylene blue dye from aqueous solution. Some practical parameters affecting adsorption process, in both clays, such as initial dye concentration and the thermodynamic parameters (ΔHo, ΔGo, ΔSo) for the adsorption process also computed and compared. Materials and Methods: Ten milliliters of different concentrations of methylene blue solutions (5, 10, 15, 20, 25, 30, 35, 40, 45, 50 mg/L) were mixed in water shakerbath with 0.05g of bentonite clay. Supernatants were separated by centrifugation. UV-Visible spectrophotometer technique used to follow up the adsorbed quantities after mixing the dye solution with bentonite. The experiment repeated at three different temperatures (5, 25, 45°C) to measure the thermodynamic parameters (ΔHo, ΔGo, ΔSo) for the adsorption process. Results: The extent of the methylene blue removal by Iraqi bentonite increased with increase in the initial concentration of the dye and with decrease temperature. Thermodynamic parameters, such as ΔHo, ΔGo, and ΔSo have been calculated by using the thermodynamic equilibrium coefficient obtained at different temperatures and concentrations.