Acrylamide Cross-Linked Psyllium Polysaccharide with Improved Flocculation Performance for the Removal of Microplastics from Water

Abstract

This article presents a novel material of acrylamide (AM) cross-linked psyllium polysaccharides (PLP) derivative, PLP-AM, which can be used as an effective polymeric flocculant for the removal of microplastics (MP) from water. PLP-AM was produced by radical polymerization of PLP and AM using microwave irradiation instead of conventional radical initiators. The characterization of PLP-AM was carried out by FT-IR spectroscopy, elemental analysis, intrinsic viscosity measurement and thermogravimetric analysis (TG). Polystyrene (PS), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) were utilized to examine the flocculation performance of PLP-AM. The optimum flocculation conditions were obtained by the comprehensive exploration of flocculant concentration, solution pH and temperature. In a solution with a pH 6 at 30 °C, the maximum removal percentages of PS and PVC by 60 mg/L of PLP-AM were 92.55 % and 94.31 %, respectively, while 93.85 % of the maximum removal of PET percentage could be obtained by 80 mg/L of PLP-AM. The results of zeta potential measurement revealed that there was adsorption electric neutralization between MP and PLP-AM besides the adsorption bridging mechanism. These results suggest that PLP-AM may bring an inspiration for the development of polymer flocculant to remove MP from water.