Removal of methylene blue dye from aqueous solution by adsorption onto sodium humate/polyacrylamide/clay hybrid hydrogels.
A type of novel hybrid hydrogels from sodium humate (SH), polyacrylamide (PAM), and hydrophilic laponite clay were prepared using potassium persulfate (KPS) as the initiator and N,N'-methylenebisacrylamide (MBA) as the cross-linker. The morphology of the hydrogels was characterized by field emission scanning electron microscope (FESEM). The adsorption-desorption kinetics of methylene blue (MB) were also investigated. It was shown that SH/PAM/clay hydrogels exhibited excellent performance in MB adsorption. The maximum absorption concentration of MB was 800 mg/l/g of hydrogel. The adsorption concentration of hydrogels increased with increasing SH or clay content. Less MB were desorbed with increasing SH content, while the clay content had no significant influence on the amount of MB desorbed. This effect was attributed to the formation of a ionic complex between the imine groups of MB and the ionized carboxylic groups of SH. MB diffusion process was dominant in MB desorption.
Yi
Ju-Zhen
JZ
School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, PR China. cesyjz@mail.sysu.edu.cn <cesyjz@mail.sysu.edu.cn>
Zhang
Li-Ming
LM
D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D006812:Humic Substances / Q000032:analysis*; D020100:Hydrogels / Q000737:chemistry*; D007700:Kinetics; D008751:Methylene Blue / Q000302:isolation & purification*; D012996:Solutions; D014867:Water / Q000737:chemistry*; D000099166:Polyacrylamides
D000180:Acrylic Resins; D000538:Aluminum Silicates; D000077215:Clay; D006812:Humic Substances; D020100:Hydrogels; D008751:Methylene Blue; D012996:Solutions; D014867:Water; D000099166:Polyacrylamides