摘要
采用连续液流法研究了黄土性土壤吸附、解吸磷酸根的动力学性质。结果表明：（１）供试土壤对磷酸根的吸附、解吸按速率可分为快、中、慢三种反应类型；（２）描述吸附、解吸反应的最优模型均为Ｅｌｏｖｉｃｈ方程，最差模型分别为一级反应方程及双常数方程，拟合差的模型对反应速率变化“敏感”，可用于反应类型划分和机理研究；（３）粘粒含量及代换量对吸附速率有显著影响，游离铁对吸附速率、ＣａＣＯ＿３对较低温度下的吸附及较高温度下的解吸速率也有明显影响，速效磷含量是控制解吸速率的重要因子；（４）升高温度吸附加速，但对解吸速率无明显影响；（５）不同土类及同一剖面不同层次的吸附、解吸速率，反应时间及吸附、解吸量不同。
Kinetics characteristics of phosphate
adsorption-desorption by Loessial soiis werestudied under the conditions of continuous liquid
current.Phosphate was adsorbedand desorbed at different rates.According to the rate,the
reaction of adsorbing-desorbing could be divided into three types:fast.middle and slow
reactions.Elo-vich equation was the best model to decribe the adsorption and desorption of
phos-phate,while the first-order and parabolic diffusion equations were the worst; butthe worst
models were “sensitive”to the changes of reaction rate and could be usedto classify
reaction type and to study the reaction meachanism. The rates of adsor-ption and desorption
were closely related to the soil clay and CEC. The influencesof free Fe_2O_3 on adsorbing rate
and CaC_3 on adsorbing rate under lower tempera-ture and desorbing rate under higher
temperature were siginficant.The rapiddlyavailable phosphorus was an important factor to
control tlie desorption rate.Therate of phosphate adsorption was significantly influenced by
temperature,but theeffect of temperature on the desorption rate was not significant.The
adsorption anddesorption rates, capacity of phospbate and reaction time varied with soil types
andhorizons.
出处
《土壤学报》
CAS
CSCD
北大核心
1995年第2期142-150,共9页
Acta Pedologica Sinica
关键词
土壤化学动力学
磷吸附动力学
磷解吸动力学
Chemical kinetics of soils,Phosphate adsorption kinetics,Phos-phate
desorption kinetics,Phosphat adsorption,Phosphate desorption
