Poly(Acrylic Acid)/Bentonite Composites for Removing High Concentration of Methylene Blue

Abstract

The poly (acrylic acid)/Bentonite composites (PAA/Bent) was prepared by in-situ polymerization. The structure of PAA/Bent was characterized by FT-IR, XRD and SEM, which indicated that AA intercalated into the interlayers of bentonite, and composite was formed between Bent and PAA. The PAA/Bent was used as a polymer adsorbent to remove methylene blue, a typical cationic dyes. Some important influencing factors on removing MB by PAA/Bent were investigated. The optimum adsorption conditions were obtained as following: the PAA/Bent dosage is 0.08 g, contacting 20 min at room temperature (25 °C), the pH value had little effect on MB adsorption, PAA/Bent can be used to treat wastewater with a broad range of pH value. The removal ratio of MB got to 99.4 %, and the adsorption capacity was 310.7 mgg-1. The removal mechanism is also investigated. It was charge neutralization and physical adsorption. In summary, the results indicated that PAA/Bent is an effective adsorbent and can be used to treat high concentration of MB wastewater.