Nature Environment and Pollution Technology

Lingfeng Zhu ¹, Weiyong Zhu ¹, Xiaoqi Chai ¹, Yingying Li ¹, Guoting Li ¹

Affiliations
1 Department of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450011, CN

Abstract

As one of the major oxidation intermediates generated in advanced oxidation processes, 1,4-benzoquinone is proved to be highly toxic. Adsorptive removal of 1,4-benzoquinone by sugarcane bagasse, a low-cost agricultural waste, was systematically investigated. It was observed that most of the adsorption occurred within the initial 30 min. The results showed that Elovich kinetic model could better describe the kinetic data under all the solution pH conditions examined by non-linear regressive method. Pseudo-second-order kinetic model apparently fitted the experimental data better than pseudo-first-order kinetic model when using linear simulation method. The adsorption process was highly pH dependent, with the greatest adsorption occurring under neutral pH condition, and the highest uptake of 4.5 mg/g was achieved at pH 8.0. Ionic strength test indicated that 1,4-benzoquinone adsorption might form outer-sphere surface complexes with sugarcane bagasse. Natural organic matter (humic acid) significantly inhibited the uptake of 1,4-benzoquinone onto sugarcane bagasse. The study showed that sugarcane bagasse has a great potential application for the adsorptive removal of toxic 1,4-benzoquinone.

Keywords

Sugarcane Bagasse, 1,4-Benzoquinone, Biosorption, Kinetics, Water Purification.

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Guoting Li ¹, Yanmin Feng ¹, Xiaoqi Chai ¹, Xiaoshuang He ¹

Affiliations
1 Department of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450011, CN

Abstract

Fly ash, an industrial waste from thermal power plants, was used for the adsorptive removal of 1,4-benzoquinone, one of the oxidation intermediates generated in AOPs. Effect of fly ash dosage and solution pH was investigated. The highest 1,4-benzoquinone uptake occurred at pH 7.0. Neutral and alkaline conditions were more favourable for the adsorptive removal of 1,4-benzoquinone. Isotherm data at 288, 298 and 308 K were simulated by Langmuir, Freundlich, Temkin, Redlich-Peterson, Koble-Corrigan and Dubinin- Radushkevich isotherm models. Both the Koble-Corrigan and Dubinin-Radushkevich isotherms can predict equilibrium adsorption behaviour better at different reaction temperatures. The reaction enthalpy was 29.42 kJ/mol and the entropy achieved 164.52 J/mol·K. The change of Gibbs free energy achieved -19.48 kJ/mol at 298 K. The above indicates that the sorption process was spontaneous and endothermic. This also reveals that, fly ash has the potential for the adsorptive removal of 1,4-benzoquinone.

Keywords

Adsorption, 1,4-Benzoquinone, Fly Ash, Kinetic Model, Isotherm Model.

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