Background

In the last few decades the quality of natural water has often deteriorated as a variety of novel pollutants have contaminated rivers and lakes. Trace amounts of some man-made chemicals can be hazardous to plants, animals as well as human health as carcinogens, mutagens or endocrine disruptors . Light radiation may help in its decomposition, aided by naturally occurring colored organic compounds (humic substances) in the water . The aim of these studies was to check the influence of presence of organic and inorganic matter on the removal of endocrine disrupting compound - butylparaben (BP) from water.

Methods

Photochemical decomposition of BP in aqueous solution using: photolysis by ultraviolet-C (UVC) and visible (VIS) irradiation, advanced oxidation in H₂O₂/UV system and photosensitized oxidation was examined. The degradation processes were carried out in different type of water matrix: natural water from Sulejow Reservoir, simulated natural water with humic acids and buffered solution.

Results

The presence of dissolved organic matter in water did not influence much on UVC photolysis and increases only about 8% of BP depletion rate in H₂O₂/UV system. While during visible light photolysis and photosensitized oxidation the addition of natural water matrix causes the acceleration of reaction rate by 16% and 36%, respectively. Moreover BP degradation proceeds via singlet oxygen generated from humic substances.

Conclusions

Butylparaben undergoes both direct and indirect photodegradation in aqueous solution under UVC and visible radiation. The efficiency of the H₂O₂/UV process, photolysis as well as photosensitized oxidation processes is strongly dependent on composition of the water.