Value-added utilization of paper sludge: Preparing activated carbon for efficient adsorption of Cr(VI) and further hydrogenation of furfural

Qingqing Guan; Kexuan Gao; Ping Ning; Rongrong Miao; Liang He

doi:10.1016/j.scitotenv.2020.140265

Value-added utilization of paper sludge: Preparing activated carbon for efficient adsorption of Cr(VI) and further hydrogenation of furfural

Sci Total Environ. 2020 Nov 1:741:140265. doi: 10.1016/j.scitotenv.2020.140265. Epub 2020 Jun 16.

Authors

Qingqing Guan¹, Kexuan Gao¹, Ping Ning¹, Rongrong Miao¹, Liang He²

Affiliations

¹ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, China.
² BiomassChem Group, Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China; The Higher Educational Key Laboratory for Phosphorus Chemical Engineering of Yunnan Province, Kunming University of Science and Technology, Kunming 650500, Yunnan, China. Electronic address: heliangkmust@163.com.

PMID: 32585483
DOI: 10.1016/j.scitotenv.2020.140265

Abstract

After normal alkali treatment process, the industrial Cr(VI) containing wastewater still contains a ppm level of Cr(VI) ions which should be further purified before discharging. In this study, the Cr(VI)-containing wastewater has been efficiently treated by the porous paper sludge-based activated carbon (psAC) with an excellent specific surface area and rich oxygen functional groups. The batch experimental results showed that under acidic conditions, pH has little effect on the Cr(VI) removal. The kinetic and isotherms studies showed that the Elovich and Freundlich model could describe the adsorption process well and the maximum adsorption capacity of psAC was 54.04 mg/g. The thermodynamic studies indicated that the reaction process was endothermic and spontaneous. Adsorption enthalpy was 17.37 kJ/mol, showing that the chemisorption process was a hydrogen bonding-controlled that has been also verified by some analytical techniques. Lastly, this study also provided an idea for reutilization of waster Cr(VI)-contained psAC in furfural hydrogenation.

Keywords: Activation; Adsorption; Cr(VI); Paper sludge-based activated carbon; Waste control by waste.