The present invention relates to disinfection of water polluted by microbial pathogens through the use of photosensitizers. The photosensitizer is a porphyrinoid which is part of an adduct comprising a resin, a spacer and said porphyrinoid. An apparatus wherein said adduct is excited by light sources and water is disinfected while flowing inside the apparatus is also provided. A system for the disinfection of water comprising said apparatus and further elements is also within the scope of the invention.
