title: The adsorption of cationic dye from aqueous solution onto acid-activated andesite.
abstract: The adsorption of cationic dye (i.e., methylene blue) onto acid-activated andesite in aqueous solution was studied in a batch system with respect to its kinetics as a function of agitation speed, initial adsorbate concentration, pH, and adsorbent mass. It was found that the resulting acid-activated adsorbent possessed a mesoporous structure with BET surface areas at around 60m(2)/g. The surface characterization of acid-activated andesite was also performed using the zeta-potential measurements, indicating that the charge sign on the surface of the andesite should be negative in a wide pH range (i.e., 3-11). Furthermore, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of methylene blue onto the clay samples treated under different process conditions. It was found that the adsorption process could be well described with the model. The adsorption capacity parameter of the model obtained in the present work was significantly in line with the process parameters.
authors.affiliation: Graduate Institute of Bioresources, National Pingtung University of Science and Technology, Pingtung 912, Taiwan. wttsai@mail.npust.edu.tw
authors.forename: Wen-Tien
authors.initials: WT
authors.lastname: Tsai
authors.forename: Hsin-Chieh
authors.initials: HC
authors.lastname: Hsu
authors.forename: Ting-Yi
authors.initials: TY
authors.lastname: Su
authors.forename: Keng-Yu
authors.initials: KY
authors.lastname: Lin
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Lin
authors.forename: Tzong-Hung
authors.initials: TH
authors.lastname: Dai
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D004396:Coloring Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry*; D012996:Solutions; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D004396:Coloring Agents; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; D011791:Quartz; D000077215:Clay; D008751:Methylene Blue