Advanced Treatment Technologies for the Removal of Organic Chemical Sunscreens from Wastewater: a Review

Organic ultraviolet (UV) filter compounds are crucial components of sunscreen products, which are used to absorb UV radiation. However, the increase in consumption of UV filters has led to environmental concerns about their impacts on the environment and human health. This review found that the high lipophilicity and stability of UV filters can cause bioaccumulation leading to a wide range of adverse ecological effects. UV filters' concentration was detected in wastewater up to ppm, and their physicochemical characteristics such as the size of molecule, pK(a), hydrophobicity, and solubility significantly control their fate in the environment. Among UV filter compounds, benzophenone 3 (BP-3) and benzophenone 4 (BP-4) are the most common in wastewater. Various removal technologies for UV filters have recently been applied, including membrane separation, adsorption, advanced oxidation processes, and phytoremediation. Among them, hybrid treatment processes such as membrane bioreactors (MBRs) can remove UV filter compounds from wastewater with a removal efficiency of up to 96% (i.e., octocrylene and benzophenone-3). Future investigation should focus on developing green/eco-friendly sunscreens to reduce hazard impacts on human health and the environment.