title: Adsorptive removal of As(III) ions from water using spent grain modified by polyacrylamide.
abstract: In order to enhance the removal efficiency of As(III), a pre-oxidation process is generally applied first to convert As(III) to As(V), which may cause unwanted new contaminants. To overcome this problem, efforts were made to develop an effective way to remove As(III) directly without an oxidation step. The effect of polyacrylamide polymers (PAMs) such as anionic PAM, cationic PAM and nonionic PAM, on As(III) ion adsorption by spent grain (SG) was investigated. The physico-chemical properties of the three PAM-polymerized SGs (APSG (anionic PAM-polymerized modified spent grain), CPSG (cationic PAM-polymerized spent grain) and NPSG (nonionic PAM-polymerized spent grain)) were analyzed using Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and zeta potential. Batch experimental data showed that the sequence of preferential adsorption for As(III) was APSG>CPSG>NPSG. Active functional groups such as amino group (NH2), carbonyl group (CO), C-N bond of the amide group (CONH2), and hydroxyl group (O-H) were responsible for As(III) adsorption. Many tubular structures occurring on the surface of APSG possibly increase the specific surface areas and favor the adsorption of As(III) ions. A fixed-bed study was carried out by using APSG as an adsorbent for As(III) from water. Three factors such as bed height, initial concentration and flow rate were studied, and breakthrough curves of As(III) were obtained. The Adams-Bohart model was used to analyze the experimental data and the model parameters were evaluated.
authors.affiliation: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Jiangxi 341000, China.
authors.forename: Yunnen
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Jiangxi 341000, China.
authors.forename: Changshi
authors.initials: C
authors.lastname: Xiong
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D001151:Arsenic / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D001151:Arsenic; D014874:Water Pollutants, Chemical; D000099166:Polyacrylamides
keywords: Adsorption; Arsenite (As(III)); Functional groups; Polyacrylamide (PAM); Spent grain (SG)