A web-based survey has been performed in order to visualize the never ending interest on the topic "photocatalysis" since 1990. Studies related to photocatalysis have been continuously increasing throughout the literature for two decades. In this review, special emphasis is directed to photocatalytic degradation of pollutants in the presence of natural organic matter (NOM) using TiO2 as the photocatalyst. Considering the diversity in surface waters, major concern will be on critical evaluation of the "NOM effect" on the photocatalytic degradation of organic compounds. To provide a broader perspective of NOM properties for the assessment of its role in photocatalytic degradation process of priority pollutants (PPs) and organic emerging contaminants (ECs), recent literature findings are surveyed. Current limitations and future research needs are discussed. (C) 2016 Elsevier B.V. All rights reserved.