The Adsorption Kinetics and Modeling for Nickel (II) Removal from Wastewater by Iron-Modified Light Expanded Clay Aggregates

Document Type: Original Article

Authors

Department of Chemical Engineering, Petroleum University of Technology, Abadan, Iran

Abstract

Light expanded clay aggregate (LECA) coated with iron oxide (Fe2O3) was tested as a sorbent in the removal of Ni (II) from contaminated water. The efficiency of sorbent was investigated using operational parameters including contact time, initial pH, sorbent dosage and initial Ni (II) concentration in a batch wise mode. Furthermore, adsorbent characteristics were examined before and after modification using X-ray Fluorescence Spectroscopy, Scanning Electron Microscopy, X-Ray Diffraction and Fourier Transform Infrared spectroscopy analysis. Kinetics study was conducted to assess adsorption mechanism. The results showed that the Ni (II) sorption kinetic data fitted better by a pseudo second–order kinetic model. The Freundlich, Langmuir, Brunauer-Emmett-Teller and Temkin isotherm models were used to express the equilibrium sorption data. The Freundlich isotherm model had the best agreement with the equilibrium data compared to other isotherm models. The modified LECA had a sorption capacity of 25.2 mg of Ni (II) ions per gram adsorbent. A 97% removal efficiency of Ni (II) from aqueous medium was reached at   pH 6.

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