水洗和酸洗蛭石体系中Mn^(2+)吸附的差异分析

Comparison of Mn^(2+) ion adsorption between water and acid rinsed vermiculite samples

以水洗和酸洗蛭石为吸附剂,研究了固/液吸附体系中Mn2+的吸附特性。结果表明,水洗和酸洗蛭石体系Mn2+离子的吸附都存在明显的离子和吸附剂浓度效应,水洗蛭石体系Mn2+离子的去除率显著高于酸洗蛭石体系。在酸洗过程中,蛭石表面部分吸附位被H+离子占据,降低了阳离子的交换能力。酸洗蛭石的吸附容量低,在吸附过程中H+离子的解吸会降低出水溶液的pH值,不宜作为湿地基质填料。

The experiments were conducted to analyze the characteristics of Mn^2＋ ion adsorption in liquid/solid systems by using water and acid rinsed vermiculite samples as the sorbents. Significant adsorbate and adsorbent effects were observed in the tested systems for both water and acid rinsed samples. The vermiculite samples rinsed by distilled water had much more higher Mn^2＋ ion removal rate than the samples rinsed by diluted sulfuric acid. The adsorption capacity of vermiculite was lowered in the acid rinsing process due to occupation of large amounts of surface adsorption sites by H^＋ ion. Acid rinsing not only caused an apparent reduction in Mn^2＋ ion adsorption but also led to significant decreases in solution pH. The results obtained from the present tests indicate that the acid rinsing was not a suitable measure for preparation of vermiculite samples to be used as fillers in constructed wetlands.