The Optimization Parameters of Activated Biochar Derived From Pine Pyrolysis: Application in Methylene Blue Adsorption

Abstract

To understand the interaction mechanism between adsorbent and adsorbate, activated biochar, prepared from pine sawdust using CO2 and H2O as activator, was employed to adsorb methylene blue in printing and dyeing pollutants. The pore structure, carbon structure of the aromatic ring system, and functional groups were investigated though SEM, nitrogen adsorption/desorption device (BET), Raman, and XPS characterization, and the adsorption kinetics and possible adsorption mechanism were also studied. The results showed that the activated biochar prepared by CO2 activation had more specific surface area, pore structure, and surface oxygen-containing functional groups than that prepared by H2O, which was more conductive to improving its adsorption capacity. The electrostatic interaction between the surface oxygen-containing functional groups in the adsorbents and the π-π interaction formed in the aromatic rings enhanced the adsorption capacity of activated biochar to methylene blue. The adsorption process of methylene blue by activated biochar was spontaneous, and it conformed to the pseudo-second-order kinetic characteristics and Langmuir adsorption isotherm equation. It was a monolayer adsorption and the maximum adsorption capacity was about 160 mg/g. Activated biochar as an adsorbent for wastewater treatment has promising application and development prospects.

Using Activated Biochar from Caryocar brasiliense Pequi Almonds for Removing Methylene Blue Dye in an Aqueous Solution

“…The band in the two studied biochars, around 1100 cm −1 , is attributed to symmetrical C-O-C stretching vibrations after adsorption [53]. The band around 470 cm −1 in the ABA biochar, representing a C = O bond, disappeared after the adsorption process, probably due to the interaction with the MB [54]. The bands remained around 900 cm −1 for the BAA material, which is attributed to the C-H bond [55,56].…”

Preparation, Modification, and Application of Biochar in the Printing Field: A Review

“…Biochar shows great potential for dye adsorption due to its large specific surface area, porous structure, abundance of surface functional groups, and low cost [119,120] (Figure 6). However, pristine biochar usually lacks excellent adsorption properties, and the use of physical or chemical modifications to improve the surface groups and porous structure of biochar can significantly increase its adsorption capacity for removing pollutants from wastewater [121,122]. surface groups and porous structure of biochar can significantly increase its adsorption capacity for removing pollutants from wastewater [121,122].…”

“…However, pristine biochar usually lacks excellent adsorption properties, and the use of physical or chemical modifications to improve the surface groups and porous structure of biochar can significantly increase its adsorption capacity for removing pollutants from wastewater [121,122]. surface groups and porous structure of biochar can significantly increase its adsorption capacity for removing pollutants from wastewater [121,122]. Chen et al [123] used corn stover carbon activated by K2CO3 for the decolorization of printing wastewater and investigated the adsorption of methylene blue (MB) and gentian violet (GV).…”