Effects of ammonium chloride and potassium chloride on kinetics of phosphorus sorption of Taihu Paddy soil
Translocation,plant availability,and hazard potential to water environment of soil phosphorus are related with phosphorus sorption of soil,and it is very common to apply fertilizer by compounding ammonium,potassium and phosphorus together in agricultural production.In this article,the effects of ammonium chloride and potassium chloride on kinetics of phosphorus sorption of paddy soil were conducted by the batch culture,and kinetics of phosphorus sorption was fitted to different models.The results showed that amounts of adsorbed phosphorus were significantly increased by the addition of ammonium chloride and potassium chloride,and there is no significant difference in amounts of phosphorus sorption between ammonium chloride and potassium chlo-ride at the same mole number at the initial culture period,but amounts of phosphorus sorption treated with potas-sium chloride was significantly more than that of phosphorus sorption treated with ammonium chloride at the same mole number during the period of 15 min to 10 d.Synergistic effect on amount of phosphorus sorption was showed in the case of being treated with ammonium chloride and potassium chloride together,but effect of potas-sium chloride on phosphorus sorption plays a leading role.Effect of ammonium chloride on total amounts of phosphorus sorption was not significant,while the effect of potassium chloride on total amount of phosphorus sorption was significant,but there is no significant difference in total amounts of phosphorus sorption between ammonium chloride and potassium chloride.Comparison of the coefficients of determination(R2) of different models indicated that the order of equations fitted by the data of phosphorus sorption was ET(elovich type equa-tion) TC(tow constant rate equation) PD(parabolic diffusion equation) ZO(zero order equation) FO(first order equation) SO(second order equation).