Adsorption behavior of 2,4-DCP by rice straw biochar modified with CTAB

ABSTRACT

In this study, rice straw was used as the raw materials of biomass carbon to prepare biochar at different temperatures (400°C, 500°C, 600°C, 700°C, and 800°C). In addition, cetyl trimethyl ammonium bromide (CTAB) modified biochar was used to treat 2,4-dichlorophenol (2,4-DCP) in water. The influences of adsorbent dosage, solution pH, adsorption time, and initial solubility of the 2,4-DCP solution on the adsorption properties were investigated. The physicochemical properties of biochar were investigated using SEM, FT-IR, BET surface area, and pore size analysis. The results showed that the pyrolysis temperature had a great influence on the biochar structure. CTAB provided hydrophilic and hydrophobic groups to the modified biochar, which had increased adsorption capacity comparing to unmodified biochar. The pH also had a significant effect on the adsorption performance of biochar, and the adsorption performance of biochar decreased significantly under alkaline conditions. The maximum adsorption capacities of modified biochar and unmodified biochar were 59.81 and 20.89 mg/g, respectively, indicating that the adsorption capacity of modified biochar was significantly higher than that of unmodified biochar. The adsorption process of 2,4-DCP by rice straw biochar conformed to the Second-order kinetic model and the Freundlich isotherm adsorption model.

GRAPHICAL ABSTRACT

KEYWORDS:

• Biochar
• adsorption
• modification
• 2,4-DCP
• mechanisms

Acknowledgements

This work was supported by the National Natural Science Foundation of China (grant number 41571306 and No. 41501537), the Project of Excellent Fund in Hubei (grant number 2018CFA067), the Major Project of Science and Technology research Program of the Hubei Provincial Department of Education (grant number D20181101) and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources (grant number 2017zy003).

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Dajun Ren http://orcid.org/0000-0003-0752-4184

Zhaobo Wang http://orcid.org/0000-0002-8949-1373

Additional information

Funding

This work was supported by the National Natural Science Foundation of China: [Grant Number 41501537,41571306]. the Major Project of Science and Technology research Program of the Hubei Provincial Department of Education (grant number D20181101) and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources (grant number 2017zy003).