Open AccessHexavalent chromium removal from aqueous solution by adsorbents synthesized from groundwater treatment residuals
Author(s) -
Chi-Chuan Kan,
Aldwin H. Ibe,
Kim Katrina P. Rivera,
Renato O. Arazo,
Mark Daniel G. de Luna
Publication year - 2017
Publication title -
sustainable environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.061
H-Index - 29
ISSN - 2468-2039
DOI - 10.1016/j.serj.2017.04.001
Subject(s) - hexavalent chromium , adsorption , freundlich equation , ionic strength , chemistry , chemisorption , chromium , aqueous solution , wastewater , nuclear chemistry , groundwater , inorganic chemistry , environmental engineering , organic chemistry , environmental science , geology , geotechnical engineering
In this study, silica sand coated with groundwater treatment residuals was used as adsorbents for the removal of hexavalent chromium from synthetic wastewater. Batch adsorption experiments were conducted to evaluate the effects of initial Cr(VI) concentration, solution pH, adsorbent dosage, solution temperature, contact time, as well as ionic strength on Cr(VI) removal. Results show that low solution pH and high ionic strength improve Cr(VI) adsorption onto the residual coated sand. At pH 4, the highest adsorption capacity was computed at 0.27 mg g−1. The Freundlich isotherm model best described the adsorption process. From 298 to 318 K, the high correlation of the kinetic data with the pseudo-second order model (R2 > 0.981) and a highly positive activation energy value (22.7 kJ mol−1) indicate that chemisorption is the rate-controlling step of the adsorption process