当前位置: 首页 > 文章 > 恒电荷土壤及可变电荷土壤与离子间相互作用的研究ⅢCu~(2+)和Zn~(2+)的吸附特征 土壤学报 2005,42 (2) 225-231
Position: Home > Articles > INTERACTION OF IONS WITH CONSTANT CHARGE SOILS AND VARIABLE CHARGE SOILS Ⅲ. CHARACTERISTICS OF Cu~(2+) AND Zn~(2+) ADSORPTION IN SINGLE AND CO-EXISTING SYSTEMS Acta Pedologica Sinica 2005,42 (2) 225-231

恒电荷土壤及可变电荷土壤与离子间相互作用的研究ⅢCu~(2+)和Zn~(2+)的吸附特征

作  者:
徐明岗;季国亮
单  位:
中国科学院南京土壤研究所
关键词:
Cu2+吸附;Zn2+吸附;恒电荷土壤;可变电荷土壤
摘  要:
研究了3种典型可变电荷土壤和4种典型恒电荷土壤在不同pH和不同浓度下单纯及共存体系中Cu2 + 和Zn2 + 的吸附及其影响因素。结果表明,两类土壤对Cu2 + 或Zn2 + 的吸附量均随平衡浓度增加而增大,符合Langmuir吸附等温式;当Cu2 + 、Zn2 + 浓度一定时,pH升高使Cu2 + 、Zn2 + 吸附量增大,但当pH >5时,Cu2 + 、Zn2 + 吸附量随pH变化甚微,出现一个接近最大吸附量的“平台”。当添加Cu2 + 、Zn2 + 浓度相同,但二种离子的总浓度不同时,平衡液的Cu2 + /Zn2 + 浓度比均小于1,说明两类土壤对Cu2 + 的吸附选择性大于Zn2 + ,且这种趋势不因pH和离子浓度而改变。当Cu2 + 、Zn2 + 共存时,使可变电荷土壤的Zn2 + 吸附量减小约70 % ,是恒电荷土壤降低量的约1.5倍;可变电荷土壤吸附一个Cu2 + 或Zn2 + 时所释放H+ 的平均数,明显大于恒电荷土壤者,说明可变电荷土壤对Cu2 + 及Zn2 + 的吸附中专性吸附的比例较恒电荷土壤大
译  名:
INTERACTION OF IONS WITH CONSTANT CHARGE SOILS AND VARIABLE CHARGE SOILS Ⅲ. CHARACTERISTICS OF Cu~(2+) AND Zn~(2+) ADSORPTION IN SINGLE AND CO-EXISTING SYSTEMS
作  者:
Xu Minggang Ji Guoliang(Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China)
关键词:
Adsorption;Cu 2+ , Zn 2+ ;Constant charge soils;Variable charge soils
摘  要:
Adsorptions of Cu 2+ and Zn 2+ by three typical variable charge soils and four typical constant charge soils different in pH and in accompanying ion, Na +, Zn 2+ or Cu 2+ were determined, respectively. The results showed that adsorption of Cu 2+ and Zn 2+ by the soils could be described by the Langmiur equation C/(X m)=1/Kb+C/b both in the single ion and co existing ions systems. The adsorption of Cu 2+ or Zn 2+ increased with pH and reached a plateau value when the pH value was 5. The affinity in adsorption of Cu 2+ was greater than that of Zn 2+ . The mechanism of adsorption Cu 2+ and Zn 2+ was closely related to chemical composition and surface properties of the soils. The relative contribution of specific adsorption to the adsorption of Cu 2+ and Zn 2+ by the variable charge soils was greater than that by the constant charge soils.

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