Exceptional Adsorption of Phenol and p-Nitrophenol from Water on Carbon Materials Prepared via Hydrothermal Carbonization of Corncob Residues
Baojian Liu,
Yin Li,
Xikun Gai,
Ruiqin Yang,
Jianwei Mao,
Shengdao Shan
Affiliations
Baojian Liu
Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Products, School of Biological and Chemical Engineering; Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; China
Yin Li
Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Products, School of Biological and Chemical Engineering; Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; China
Xikun Gai
Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Products, School of Biological and Chemical Engineering; Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; China
Ruiqin Yang
Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Products, School of Biological and Chemical Engineering; Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; China
Jianwei Mao
Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Products, School of Biological and Chemical Engineering; Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; China
Shengdao Shan
Zhejiang Provincial Collaborative Innovation Center of Agricultural BioResources Biochemical Manufacturing; Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, 318 Liuhe Road, Hangzhou, Zhejiang 310023 China; China
Phenol and p-nitrophenol (PNP) are priority pollutants widely present in wastewater. Developing superior or low-cost sorbents for their removal would be of great benefit. Here, corncob residues (CCR) were converted to hydrochars via hydrothermal carbonization (HTC) and further upgraded to carbon materials by thermal activation in an N2 atmosphere. The influence of HTC conditions including the temperature, residence time, and CCR/water weight ratio on the material properties and their performance for removing phenol and PNP from water were investigated and compared with those that were obtained from pyrochar (directly pyrolyzed CCR). Hydrochars showed lower adsorption capacities for phenols than pyrochar. The initial hydrothermal treatment at 220 °C and 2 h resulted in an improved porosity and 4- to 5-fold higher adsorption capacities for phenol and PNP compared with the pyrochar. However, hydrochars prepared at 250 °C or with a prolonged residence time (4 and 6 h) could not be upgraded to high performance carbon materials by thermal activation. The adsorption isotherms of both phenols on the best performance material were well correlated by the Sips model.
