Using the benzenepolycarboxylic acid (BPCA) method to assess activated biochars and their PFAS sorption abilities

Chemosphere. 2024 Mar 22:141750. doi: 10.1016/j.chemosphere.2024.141750. Online ahead of print.ABSTRACTActivated carbon (AC) has important industrial and environmental applications as it has excellent abilities to sorb contaminants such as per- and polyfluoroalkyl substances (PFAS). Current research aims to develop activated biochars (AB) from renewable biomass to replace AC that is produced from fossil feedstock. Both AC and AB are primarily comprised of condensed aromatic carbon (ConAC), the component that is the focus of this study. ConAC is characterized to determine its relationship with biochar activation conditions and PFAS sorption, which are understudied at present. Benzenepolycarboxylic acid (BPCA) markers for ConAC were quantified in steam-activated biochars (AB-Steam) and carbon dioxide-activated biochars (AC-CO2) prepared from waste timber at different temperatures (800, 850, 900 °C) and molar ratios of feedstock-carbon:steam (0.50-1.25). A non-activated biochar was also included as a reference. ConAC relative to total organic carbon content was higher in AB-Steam than AB-CO2 (92 ± 2 % vs. 81 ± 11%). The ratio of benzenehexa- (B6CA) to benzenepentacarboxylic (B5CA) acids revealed that AB-Steam also had larger ConAC clusters than AB-CO2. These findings provide novel evidence that steam activation is more effective than CO2 activation in creating ConAC. To assess how ConAC impacts AB sorption abilities, AB-Steam were used to remediate PFAS from contaminated soil...
Source: Chemosphere - Category: Chemistry Authors: Source Type: research