A study on selective chelating precipitation of palladium metal from real electroplating wastewater using chitosan and its water-soluble derivative was conducted. The pH parameter, the concentrations of chitosan and its water-soluble derivative and the chelating precipitation time were experimentally investigated, and the optimum conditions were determined. The results revealed that both chitosan and its water-soluble derivative acted as chelating precipitation agents. Rapid chelating precipitation occurred when chitosan was added to real electroplating wastewater containing the chitosan derivative, thereby improving removal efficiency of palladium in different forms up to 95% under the optimum condition of 0.2 g/L chitosan and 0.16 mg/L derivative at pH 2.5. Then, dissolution experiments showed that chelating precipitation products could be dissolved in aqua regia. Additionally, selective chelating precipitation of palladium by chitosan and its derivative was characterized using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Thus, it can be concluded that the combined utilization of chitosan and its water-soluble derivative is a promising approach method for the removal of different forms of palladium from real electroplating wastewater.

中文翻译：

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壳聚糖及其衍生物选择性螯合电镀废水中钯金属

研究了壳聚糖及其水溶性衍生物对电镀废水中钯金属的选择性螯合沉淀。对pH参数、壳聚糖及其水溶性衍生物的浓度和螯合沉淀时间进行了实验研究，确定了最佳条件。结果表明壳聚糖及其水溶性衍生物均作为螯合沉淀剂。在含有壳聚糖衍生物的实际电镀废水中加入壳聚糖发生快速螯合沉淀，从而在pH 2.5的0.2 g/L壳聚糖和0.16 mg/L衍生物的最佳条件下，将不同形态钯的去除效率提高到95%。然后，溶解实验表明螯合沉淀产物可以溶解在王水中。此外，使用X射线光电子能谱和傅里叶变换红外光谱表征壳聚糖及其衍生物对钯的选择性螯合沉淀。因此，可以得出结论，壳聚糖及其水溶性衍生物的联合利用是一种从实际电镀废水中去除不同形式钯的有前景的方法。