Due to a lack of proper regulation and enforcement in many countries, industrial effluent wastewater high in aqueous heavy metal contaminants is discharged into the environment without proper treatment leading to significant environmental issues and contamination. Current removal methods are limited because they do not allow for resource recovery, presenting a unique opportunity to avoid environmental contamination by removing aqueous heavy metals (e.g. chromium (Cr) from leather tanning, arsenic (As) from mining and smelting) from industrial wastewater using a cationic surfactant surface-modified (CSSM) biochar. CSSM biochar consists of biochar (an emerging low-cost sorbent useful for trace metals like Cr and As) coated in cationic surfactant (e.g. cetyltrimethylammonium bromide) that provides hydrophilic and hydrophobic functional groups showing potential for the modified biochar to exhibit ion exchange properties, increased adsorptive capacity for aqueous toxic metals (Cr2O72- or HCrO4-, etc.), improved selectivity, CSSM biochar regeneration (through backwashing with a high ionic strength solution), and greater overall performance when compared with traditional methods of remediation. Although many surface properties of modified biochar have been characterized, ion competition and selectivity potential of the adsorbent surface of CSSM biochar have often been overlooked when performing initial studies, missing the crucial information needed to understand the scalability of the material for industrial applications (e.g. tannery wastewater). Our objective is to investigate a sustainable and economically viable method for CSSM biochar to be used for the efficient recovery of aqueous oxyanion contaminants in industrial systems through ion exchange modeling, adsorption isotherms, kinetics, SEM, FT-IR, and other established methods. To effectively remediate and recover aqueous oxyanions from industrial wastewater streams, the role of ion competition must be addressed to determine which target ions of consideration (i.e. Cr, As) have an affinity for the CSSM biochar surface when in the presence of other common competing ions found in industrial wastewater.

Selective adsorption and recovery of aqueous heavy metal contaminants from industrial wastewater using cationic surfactant surface-modified biochar

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.