Immobilized Rose Bengal for Water Disinfection

Kate Adar Raik, Ariel University, Ariel, Israel
Marina Nisnevitch, Chemical Engineering, Biotechnology And Materials, Chemical Engineering, Ariel, Ariel University

Lack of fresh water is emerging as a major global problem, primarily due to pollution-related issues. Current disinfection methods are limited by a number of disadvantages such as high cost, toxic decay byproducts, and need for retreatment. However, photosensitizers (PS) are characterized by efficient anti-bacterial activity and can be used to eradicate pathogenic microbial cells. In order to design an efficient technological scheme of wastewater treatment, it is necessary to immobilize the PS onto a polymeric support. Immobilization allows for reuse of PS and their separation from water after treatment. In addition, immobilization can increase the resistance of PS to bleaching. The aim of this research is to select conditions for PS immobilization in a polymer and to find optimal operating wastewater disinfection parameters. The immobilization of the PS was carried out by dissolution in a melted polymer. Rose Bengal Lactone and Rose Bengal sodium salt were the chosen PS and the polymer support was polyethylene. After the immobilization, grains of 3-5 mm diameter and length, with homogeneous distribution of the PS in the polymer, were obtained. The disinfection activity of the immobilized PS was tested on Gram-positive S. aureus and Gram-negative E.coli in batch and continuous regimes. The results show that immobilization onto the polymeric support PS was effective in eradication of bacterial cells.