Abstract: Polycyclic aromatic hydrocarbons (PAHs) are the ubiquitous organic pollutants in the environment,and their degradation has been of public concern.Among the degradation ways of these pollutants in the environment,photodegradation is the important one.We summarized the research advance in the photodegradation of PAHs in gas,liquid,and solid phases,with the focus on the photodegradation rate in liquid media,its affecting factors,intermediates,mechanisms and dynamics,and photoactivebiological oxidation.At present,it is urgent to establish systematic and effective methodologies in studying the photodegradation of PAHs to understand the related mechanisms and affecting factors exactly.

Key words: Rare earth element, Plant, Biological effect, Mechanism