The development of a highly efficient photo-initiator system and its application in the photo-immobilization of activated sludge

In this study, a highly efficient photo-initiator system was developed, which contained potassium persulfate, N, N, N ′, N ′ -tetramethylethylethylenediamine plus benzil dimethyl ketal. The photo-initiator system could successfully initiate poly (ethylene glycol) dimethyl-acrylate prepolymer to polymerize and crosslink under the irradiation of UV rays, in the presence of concentrated activated sludge, finally leading to the formation of immobilized activate sludge pellet beads. The presence of O 2 and thickness of the reaction solution did not influence the photo-immobilization process. Respiratory measurement result demonstrated that most activated sludge kept alive during the photo-immobilization. Mechanical strength of the immobilized cells could be improved by optimizing contents and ratio of the initiator system. The corresponding mechanism was also discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 39838.