Abstract

The objective of this study is to explore the mechanism of phosphorus adsorption n the bioretention media. The phosphorus adsorption characteristics of four media f bioretention are studied by four isothermal adsorption experiments. The esult indicate that the maximal adsorption capacity (qm) of phosphorus of the our bioretention media are found to be media I (0.3365 mg/g), media II (0.3302 g/g), media III (0.2751 mg/g) and media IV 0.8435 mg/g), respectively. The egative values of Gibbs free energy of phosphorus indicate that each of the hosphorus adsorption process by the four bioretention media is a spontaneous rocess. The mean sorption energies obtained from DR isotherm were 0.0758, .0772, 0.0803 and 0.0632 kJ/mol respectively, which indicate the physical nature f the adsorbate/adsorbent interactions. Two kinetic models including pseudo irst-order and pseudo second-order equation were selected to follow the adsorption rocess. The results showed that the adsorption of phosphorus with the our types of bioretention media could be described by the pseudo second-order quation. The media IV was the better media of bioretention with high phosphorus emoval capacity.