Removal of humic substances by the synergistic effect of biochar adsorption and activation of persulfate

Towards synergistic combination of biochar/ultrasonic persulfate enhancing removal of natural humic acids from water

“…8d, the virgin biochar could remove more than 90.0% of HAs in 2 h, but only 68.0% and 55.0% of HAs were removed after the second and the third recycles (cycle 2 and 3) respectively. The biochar/persulfate/ultrasonic system presented better recycling capacity of biochar, since the removal efficiency decreased from 87.0% to 39.0% for the second recycle, and 28.0% for the third recycle in our previous combined biochar/persulfate system [15]. The reason may be that when the ultrasonic treatment acts on the liquid, it would produce a large number of cavitation bubbles, which could produce shock waves around, so as to separate the organics adsorbed on the surface of biochar and release active sites [60].…”

“…Changes in concentration of HAs, composition and TOC during the reaction process were measured as described in our previous work [15]. Wavelength scan and gel permeation chromatography (GPC) were used to further investigate the change of molecular weight and the removal of HAs.…”

“…The synthesis and characterization of the biochar were described in our previous study [15]. Chemicals such as 5,5-dimethyl-1-pyrroline N-oxide (DMPO, purity>99.0%) were obtained from Sigma-Aldrich.…”

“…The removal rate of HAs was calculated as described in our earlier investigation [15]. The removal kinetics of HAs were analyzed using the following pseudo-first-order kinetic model as described with Eq.…”

Application of Biochar as Functional Material for Remediation of Organic Pollutants in Water: An Overview

“…Biochar generally has a relatively large specific surface area (SSA) with high porosity to host these active sites for envi-ronmental applications. The electron-rich OFGs, such as the ketonic (C=O) group, can mediate the catalytic reaction with the oxidant, involving the production of ROS [31]. The sp.…”