Removal of Hexavalent Chromium from Aqueous Solutions Using Sulfonated Peat

Abstract

Peat, a loose and porous material, contains rich organic matter and can be used as an adsorbent. In this study, it is chemically modified by adding sulfuric acid under different conditions, with the aim of producing a modified peat with optimized Cr(VI) adsorption capability. The modified peat exhibited a higher adsorption efficiency than the natural peat throughout the adsorption experiments. The adsorption of Cr(VI) from aqueous solutions correlates with the pseudo-second order kinetic model. In addition, the Langmuir model indicated a maximum loading capacity approximately of 105.4 mg/g, which is a markedly high value compared to some other reported adsorbents. The present study performed single factor experiments and the results indicated that higher temperature conditions result in better adsorption capability, whilst an increase in the pH played a contrary role. According to the orthogonal tests, the pH had the greatest impact on adsorption. The obtained results indicated that sulfonated peat can be effectively applied in removing Cr (VI).

Effect of the Surface Charge on the Adsorption Capacity of Chromium(VI) of Iron Oxide Magnetic Nanoparticles Prepared by Microwave-Assisted Synthesis

“…where t is the contact time in min, k 1 the first order adsorption rate constant in min −1 , q e is the equilibrium adsorption capacity in mg/g, and q t the adsorption capacity at contact time t in mg/g. The PSO model is used to explain processes ruled by the surface adsorption, as well as most environmental processes [24]. This model also indicates that the adsorption is due to physicochemical interactions between the adsorbate and adsorbent [25].…”