论文部分内容阅读
本文研究了海水中氨基酸对金属离子M(Ⅱ)-δ-MnO_2离子交换的影响。实验结果表明,在pH=1—8.5时,较高浓度(20.00ppm)谷氨酸、甘氨酸和丙氨酸以及低浓度(0.20ppm)组氨酸对Cd(Ⅱ),Zn(Ⅱ)-δ-MnO_2离子交换没有影响,而较高浓度(20.00ppm)组氨酸则有较大影响,其影响程度是Cu(Ⅱ)>Cd(Ⅱ)>Zn(Ⅱ),该序列与胺抑制影响因子F_A(ψ)序列相同。这进一步证明氨基酸在δ-MnO_2表面脱羧成胺,然后胺通过与M(Ⅱ)络合和表面吸附来抑制M(Ⅱ)-δ-MnO_2离子交换。加入氨基酸时的M(Ⅱ)-δ-MnO_2离子交换等温线仍为L-F-3型,且可用表面分级离子交换理论之等温式描述。
In this paper, the effects of amino acids in seawater on the ion exchange of metal ions M (Ⅱ) -δ-MnO_2 were studied. The experimental results showed that Cd (Ⅱ), Zn (Ⅱ) -δ (Ⅱ) and Zn (Ⅱ) at higher concentration (20.00ppm) of glutamic acid, glycine and alanine and histidine at low concentration -MnO_2 ion exchange had no effect, while the higher concentration (20.00ppm) histidine had a greater impact, the degree of influence is Cu (Ⅱ)> Cd (Ⅱ)> Zn (Ⅱ) The same sequence of F_A (ψ). This further proves that the amino acid decarboxylates to the amine on the δ-MnO 2 surface, then the amine inhibits M (Ⅱ) -δ-MnO_2 ion exchange by complexing with M (Ⅱ) and surface adsorption. The M (II) -δ-MnO 2 ion exchange isotherm at the addition of amino acids is still L-F-3 and is isothermally described by surface-graded ion exchange theory.