Carboxyl and hydroxyl groups enhance ammonium adsorption capacity of iron (III) chloride and hydrochloric acid modified biochars. (August 2020)

• Record Type: Journal Article
• Authors: Wang, Siyuan; Ai, Shaoying; Nzediegwu, Christopher; Kwak, Jin-Hyeob; Islam, Md Shahinoor; Li, Yichun; Chang, Scott X.
• Is Part Of: Bioresource technology. Volume 309(2020)
• Publication Date: 2020-08
• Subjects: Adsorption mechanism -- Ammonium -- Biochar -- Chemical modification -- Electron shuttle; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.123390
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Wheat straw biochar was modified by FeCl3 and HCl. Large surface area contributed abundant adsorption sites on modified biochars. Ammonium adsorption by biochar was controlled by chemisorption. Fe 3+ /Fe 2+ redox coupling contributed to ammonium adsorption. OCO groups in FeCl3 and HCl modified biochars enhanced ammonium adsorption. Abstract: The effectiveness of the modification of wheat straw biochar using FeCl3 and HCl, alone or combined, on ammonium adsorption was evaluated using kinetic and isotherm models. The adsorption mechanisms were studied by comparative analysis of the surface properties of the biochars before and after ammonium adsorption. The results indicate that the modification methods enhanced the ammonium adsorption capacity by at least 14%, due to the increased OH and OCO functional groups and specific surface area, and increased Fe 3+ /Fe 2+ redox coupling serving as an electron shuttle. It can be concluded that chemical modification of wheat straw biochars using FeCl3 and HCl increased the effectiveness of biochars for the treatment of ammonium-contaminated wastewater.