Remediation of Microcystis aeruginosa blooming water using a reusable polyethylenimine–polyvinyl chloride composite adsorbent

Abstract

This study aimed to apply an adsorption-based technique to directly suppress harmful algal blooms (HABs) in freshwater without causing secondary pollution. Considering the negative surface charge of the representative harmful cyanobacteria Microcystis aeruginosa of HABs in the aqueous phase, a stable and aminated sorbent polyethylenimine–polyvinyl chloride composite fiber (PEI–PVC) was applied to remove M. aeruginosa cells from the aqueous solution. The PEI–PVC fiber could directly and efficiently remove approximately 90 % of harmful cyanobacterial cells in artificial media and approximately 80 % of HABs in real environmental water without any cell lysis or destruction. During the HAB treatment process using PEI–PVC, the amount of microcystins (MCs) in the test sample was continuously decreased by simultaneous adsorption on the PEI–PVC. The PEI–PVC fiber used in this study was regenerable through desorption using an alkaline solution, and the regenerated adsorbent showed a similar cell removal efficiency to that of the original adsorbent. In addition, under light exposure, the PEI–PVC fiber did not elute any toxic chlorine into the solution, whereas pristine PVC fiber increased the chlorine concentration in the aqueous solution through photodegradation. Consequently, the adsorption-based method using PEI–PVC fiber could be a feasible and stable method for counteracting HAB contamination of water resources.