红壤,黄棕壤吸附磷酸根后对Cu^2＋次级吸附动力学

用流动法研究黄棕壤、红壤吸附磷酸根后对Ｃｕ＾２＋次级吸附的动力学。结果表明Ｃｕ＾２＋的次级吸附可用一级速率方程描述。黄棕壤吸附磷酸根后对Ｃｕ＾２＋吸附反应的速率下降；红壤吸附磷酸根后对Ｃｕ＾２＋吸附的快反应速率下降，而慢反应速率增加。升高Ｃｕ＾２＋浓度可能造成吸附反应机理的改变。竞争性阳离子Ｃｄ＾２＋和Ｚｎ＾２＋的存在降低了Ｃｕ＾２＋次级吸附反应速率。升高温度，Ｃｕ＾２＋次级吸附反应速率增加。土壤

KINETICS OF Cu~(2+) SECONDARY ADSORPTION BY YELLOW BROWN SOIL AND RED SOIL

Flow method was used to study the kinetics of Cu2+ secondary adsorption, following phosphate adsorption, by yellow brown soil and red soil, which were collected from Hubei province and Hunan province respectively. The results showed that the kinetics of Cu2+ secondary adsorption could be described well with the first-order equation.After phosphate adsorption, for yellow brown soil, the rate of Cu2+ secondary adsorption reaction decreased; for red soil the fast reaction rate of Cu2+ secondary adsorption also decreased, but the rate of slow reaction increased. The mechanism of Cu2+ secondary adsorption could be changed with an increase in Cu2+ concentration. The effect of the competitive ions Cd2+ and Zn2+ decreased the rate of Cu2+ secondary adsorption, The rate of Cu2+ secondary adsorption increased with rises in temperature. Noncrystalline iron and aluminium oxides in soils were the dominant constituents of Cu2+adsorption. Organic matter in soils could restrain the fast reaction of Cu2+ adsorption.