[Property of ammonium adsorption on sediments in ditches and adjacent soils].

Static adsorption experiments were performed to investigate the adsorption characteristics of ammonium on soils and ditch sediments. Air-dry soil, ditch sediment and wet ditch sediment were used as three kinds of sorbents. The experiments showed that the adsorption isotherms on three sorbents agreed well with linear relation and conformed to Freundlich isotherm; the adsorption ability of soil was stronger than that of ditch sediment, and for the blank ammonium concentrations of soil were higher than that of sediments. The adsorption mechanisms were related to the characteristics of interface, and ion exchange was the main adsorption function under certain concentration range. Effects of temperature on the adsorption of sorbents were observed. The results showed that the quantity of absorbed ammonium slightly decreased with the increasing of temperature under higher concentrations of ammonium.