US EPA

4829345 

Journal Article 

Influence of aromatic structure and substitution of carboxyl groups of aromatic acids on their sorption to biochars 

Wu, L; Li, B; Liu, M 

2018 

Yes 

Chemosphere
ISSN: 0045-6535
EISSN: 1879-1298 

PERGAMON-ELSEVIER SCIENCE LTD 

OXFORD 

210 

Elsevier 

239-246 

English 

30005345 

10.1016/j.chemosphere.2018.07.003 

WOS:000447112600028 

https://search.proquest.com/docview/2131869387?accountid=171501
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In order to clarify the influence of aromatic structure and COOH substitution of aromatic acids on their sorption to biochars, benzoic acid (BA), phthalic acid (PA), hemimellitic acid (HA), 2-biphenylcarboxylic acid (2-BA), 1-naphthoic acid (1-NA) and naphthalene were selected as model sorbates. Batch experiments on sorption of them to wheat straw-derived biochars at 300 °C (WS300) and 700 °C (WS700) were conducted. Results showed that WS700 with higher specific surface area and pore volume had faster and higher sorption of aromatic acids than WS300. Sorption affinity of aromatic acids decreased with increasing number of aromatic rings (BA > 1-NA > 2-BA), and was weakened by COOH substitution (BA > PA > HA). This was likely due to the π-electron delocalization into additional ring, reduced contact area of nonplanar aromatic structure on biochar surfaces, size exclusion of larger molecules in smaller pores of biochars and decreased hydrophobicity of aromatic acids by COOH substitution that abated the sorption. Dissociation of COOH substitution of aromatic acids also weakened their sorption to biochars due to the lower hydrophobicity of anionic species, and electrostatic repulsion between anionic species and negatively charged surface of biochars. 

article; Biochar; Sorption; Aromatic structure; –COOH substitution; Dissociation; electrostatic interactions; hydrophobicity; moieties; naphthalene; phthalic acid; sorbates; surface area