relation: https://khub.utp.edu.my/scholars/6789/ title: Application of response surface methodology for the optimization of hexavalent chromium removal using a new low-cost adsorbent creator: Ezechi, E.H. creator: Kutty, S.R.B.M. creator: Isa, M.H. creator: Liew, M.S. description: The adsorption capacity of a novel adsorbent (Ageratum conyzoide leaf powder) was investigated for Cr(VI) removal from aqueous solution. Experiments were designed with the Box�Behnken model of the response surface methodology (RSM). Preliminary experiments were conducted to obtain the optimum range of process variables used for the Box�Behnken model. Three independent variables (pH, initial concentration, and adsorbent mass) were examined. The results show that Cr(VI) removal was more favorable at pH 2. Increase in pH above 2 resulted in negative Cr(VI) removal. Cr(VI) removal increased when adsorbent mass was increased, but decreased with increase in initial concentration. Cr(VI) removal of 92 was obtained at pH 2 and adsorbent mass of 0.3 g. Experiments were successfully optimized by RSM. Kinetics study correlated with the pseudo-second-order kinetic model, whereas equilibrium study was best described by the Langmuir isotherm model with maximum adsorption capacity of 437 mg/g. Thermodynamic parameters indicate a spontaneous, exothermic, and physiosorption process. © 2015 Balaban Desalination Publications. All rights reserved. publisher: Taylor and Francis Inc. date: 2016 type: Article type: PeerReviewed identifier: Ezechi, E.H. and Kutty, S.R.B.M. and Isa, M.H. and Liew, M.S. (2016) Application of response surface methodology for the optimization of hexavalent chromium removal using a new low-cost adsorbent. Desalination and Water Treatment, 57 (47). pp. 22507-22518. ISSN 19443994 relation: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84952663833&doi=10.1080%2f19443994.2015.1129506&partnerID=40&md5=3a0792f40d74221bc998baf8875d2a54 relation: 10.1080/19443994.2015.1129506 identifier: 10.1080/19443994.2015.1129506