Tehran University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share this content! On (X network) By
Enhancement Adsorption of Hexavalent Chromium Onto Modified Fly Ash From Aqueous Solution; Optimization; Isotherm, Kinetic and Thermodynamic Study Publisher



Jahangiri K1 ; Yousefi N2 ; Ghadiri SK3 ; Fekri R2 ; Bagheri A4 ; Talebi SS5
Authors
Show Affiliations
Authors Affiliations
  1. 1. Department of Health in Disasters and Emergencies, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  2. 2. Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
  3. 3. Department of Environmental Health Engineering, School of public Health, Shahroud University of Medical Sciences, Shahroud, Iran
  4. 4. Department of Health, Safety and Environment, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  5. 5. Department of Epidemiology, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran

Source: Journal of Dispersion Science and Technology Published:2019


Abstract

Fly ash were successfully modified by a chemical method (iron and aluminum salts and surfactant) with the aim of removing Cr(VI) from aqueous solution. In this study, response surface methodology (RSM) and central composite design (CCD) were applied to improve the prediction models and optimize the chromium adsorption parameters. The results disclosed that surfactant-modified fly ash (SMF) had further influence on the fly ash. The predicted values showed that the quadratic model were in good agreement with the predicting values (high regression coefficient (R2>0.96), insignificant lack of fit (0.448), high F-value and low P-value (<0.05)). The optimized adsorption parameters were adsorbent dose of 3.53 g/L, initial Cr (VI) concentration of 35.40 mg/L; contact time of 69.32 min and pH of 2.77. The experimental data was described well with Freundlich isotherm (R2 = 0. 98) and pseudo-second-order kinetic model (R2 = 0. 99). The results of thermodynamic study represented that the adsorption process was spontaneous, exothermic and chemisorption (free energy (ΔG)= −30 to −40 kJ/mol and standard enthalpy (ΔH)= −41.01 kJ/mol). Therefore, cheap, ease of modification and high efficiency of fly ash has been recommended a great promise for reducing the chromium from aqueous solution. © 2018, © 2018 Taylor & Francis Group, LLC.
Experts (# of related papers)
Other Related Docs
50. Nitrate Content of Coconut Water and Its Possible Risk Assessment, Journal of Food Processing and Preservation (2021)