NH（4^＋） Adsorption in a Eum-Orthic Anthrosol at DifferentSolution／Soil Ratios and Temperatures.1
摘要
Effects of NH+ concentration, solution/soil ratio and temperature on NH+ adsorption were studied in a Eum-OrthicAnthrosol. The slopes of the soil NH+ adsorption isotherms and the fitted n, the coefficient for the adsorption intensity,and k, the coefficient related to adsorption capacity, of the Freundlich equation increased with increasing solution/soilratio (SSR) and with decreasing temperature (T). For the range of experimental conditions, the value of δq/δc, the rateof change of the amount of NH+ adsorbed in the soil solid phase (q) with respect to the equilibrium concentration of NH+in soil solution (c), was 0.840, indicating that q increased with increasing c. From 2 to 45℃, δq/δSSR, the rate of changeof q with respect to SSR, decreased from 2.598 to 1.996, showing that q increased with increasing SSR, while its increasingrate decreased with temperature. From SSR 1:1 to 20:1, δq/δT, the rate of change of q with respect to T, decreasedfrom -0.095 to -0.361, indicating that q decreased with increasing temperature, and at the same time the negative effectof temperature became larger as SSR increased. Thus under the experimental conditions the order of importance indetermining the amount of NH+ adsorbed in the soil solid phase was δq/δSSR > δq/δc > ｜δq/δT｜, indicating that thegreatest effect on the amount of NH^4+ adsorbed was with the solution/soil ratio; the equilibrium concentration of NH+had a lesser effect; and temperature had the least effect.