Extremely efficient and rapidly adsorb methylene blue using porous adsorbent prepared from waste paper: Kinetics and equilibrium studies

Xiaodong Tang; Gang Ran; Jingjing Li; Zhiqi Zhang; Chengxin Xiang

doi:10.1016/j.jhazmat.2020.123579

Extremely efficient and rapidly adsorb methylene blue using porous adsorbent prepared from waste paper: Kinetics and equilibrium studies

J Hazard Mater. 2021 Jan 15:402:123579. doi: 10.1016/j.jhazmat.2020.123579. Epub 2020 Sep 2.

Authors

Xiaodong Tang¹, Gang Ran², Jingjing Li², Zhiqi Zhang², Chengxin Xiang²

Affiliations

¹ State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, 610500, PR China; College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, PR China. Electronic address: txda429@163.com.
² College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, 610500, PR China.

PMID: 33254745
DOI: 10.1016/j.jhazmat.2020.123579

Abstract

For the first time, zinc chloride activation method was used to prepare waste paper-based activated carbon in this study. The structure, morphology, surface functional groups and particle size distribution of the activated carbon was study using automatic specific surface area analyzer, FTIR, Boehm titration, X-ray diffraction, SEM and EDS. The specific surface area of the activated carbon is up to 1987 m²/g. Cumulative pore volume is up to 2.586 cm³/g, with micropore volume accounting for 92 %. Methylene blue adsorption performance results shown that the adsorbent has achieved high removal efficiency (99.65 % in 10 min, uptake = 996.5 mg/g), its maximum adsorption capacity has reached 1657 mg/g. The pH_pzc of the adsorbent was determined to explore the adsorption mechanism, its results shown that electrostatic adsorption occurs between adsorbents and adsorbents at pH higher than pH_pzc (pH_pzc = 3.2). Moreover, adsorption mechanism was studied by various isothermal models, thermodynamic models, kinetic models. Redlich-Peterson isotherm model best describes the adsorption experiment, which indicated that the adsorption follows a non-ideal and mixed adsorption mechanism. Methylene blue molecules gone into micropore was the adsorption rate-limiting step, and MB adsorption by the waste paper-based adsorbent was a spontaneous, endothermic and randomly increasing adsorption. Simulated wastewater and regeneration experiments were also used to evaluate the adsorbent's treatment capacity and economic efficiency, and these results indicated that the adsorbent has good decolorization and regeneration ability.

Keywords: Adsorption mechanism; Methylene blue; Porous carbon; Waste paper-based activated carbon; Zinc chloride.