Photolysis, biodegradation, and sorption behavior of three selected phenolic compounds on the surface and sediment of rivers

In this study, laboratory experiments were carried out to investigate the environmental behavior of three selected phenolic compounds [2, 4-Dichlorophenol (DCP), 2, 4-Dinitrophenol (DNP) and 2, 4-Dimethylphenol (DMP)] in the aquatic environment. The results of batch sunlight photolysis experiments showed that the three phenolic compounds were photodegraded relatively easily (i.e., half-life <151 h) in June, whereas these compounds were relatively stable against sunlight in September (i.e., half-life <330 h). The results of batch biodegradation experiments using river water suggested relatively slow biodegradation (i.e., half-life <2,310 h in June, half-life <1,155 h in September, and half-life <3,466 h in January) of three phenolic compounds, and the rate constant was dependent on sampling time. Freundlich model and the pseudo second-order model can describe the sorption behaviors of phenolic compounds on sediments very well. The intraparticle diffusion model for adsorption was also investigated and compared with the pseudomodel to identify sorption mechanism.