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本文研究了高度风化的酸性红壤对Ｃｏ、Ｃｕ、Ｐｂ、Ｚｎ离子的吸附特性。用吸附曲线形状，吸附方程，分配系数，ｐＨ＿（５０）值等讨论了吸附亲和力特征及其影响因素和吸附反应的机理。结果表明，红壤粘粒吸附重金属离子主要由Ｆｅ、Ａｌ氧化物所控制。金属离子对红壤粘粒的吸附亲和力（以ｐＨ＿（５０）表示）主要决定于离子本身的化学性质，亲和力以Ｃｕ≥Ｐｂ＞ｚｎ＞Ｃｏ顺序减少，易水解的离子吸附亲和力较大，亲和力也受土壤组分及其表面性质影响，含Ｆｅ、Ａｌ氧化物多的粘粒其表面的反应活性也较大，对金属离子的亲和力较强。通过竞争吸附方程对吸附－ｐＨ曲线的描述和分配系数等的讨论，揭示出四种离子与红壤粘粒的反应机理并不相同，Ｃｕ、Ｐｂ离子以专性吸附反应为主，Ｚｎ、Ｃｏ则非专性吸附占一定比例。对专性吸附机理，可以认为从低ｐＨ时的配位机理和水解－吸附机理共存逐渐转为高ｐＨ时的水解－吸附机理为主是合理的
In this paper, the adsorption properties of Co, Cu, Pb and Zn on highly weathered red soil were studied. The characteristics of adsorption affinity, its influencing factors and adsorption reaction mechanism were discussed by the shape of adsorption curve, adsorption equation, partition coefficient and pH value. The results showed that the adsorption of heavy metals by red clay was mainly controlled by Fe and Al oxides. The adsorption affinity of metal ions to red clay (expressed as pH_ (50)) is mainly determined by the chemical nature of the ions themselves. The order of affinity decreases with Cu≥Pb> zn> Co, and the affinity for easily hydrolyzed ions is also higher Soil components and the surface properties of the impact, with Fe, Al oxides and more of its surface activity of the reactivity of the larger affinity for metal ions stronger. According to the discussion of the adsorption-pH curve and the partition coefficient of the adsorption-pH curve, we found that the reaction mechanism of the four ions is not the same as that of the red clay, while the adsorption of Cu and Pb ions is dominated by the specific adsorption reaction while that of Zn and Co Non-specific adsorption accounted for a certain proportion. For the specific adsorption mechanism, it can be considered that it is reasonable that the mechanism of hydrolysis-adsorption at the low pH and the hydrolysis-adsorption mechanism at the high pH gradually coexist