谷氨酸插层镁铝水滑石的制备、表征及其对水中铅离子的吸附性能研究

摘要

We prepared a metal salt solution using magnesium nitrate and aluminum nitrate,and a acid solu-tion that glutamic acid dissolved in decarbonated deionized water.After mixture of the salt solution and the acid crystallization,we prepared glutamate intercalated layered double Mg-Al hydrotalcite(Mg-Al-G)by a co-precip-itation method under N2 protection.Meanwhile,we characterized the hydrotalcite by IR and thermogravimetric analysis,and studied the adsorption property of the hydrotalcite to lead ion in aqueous solution.The results show that glutamic acid is dehydroxylated at 150 ℃ and decomposed at 250 ℃,and Mg-Al-G hydrotalcite is more stable when glutamic acid is intercalated into layered double hydrotalcite.Mg-Al-G hydrotalcite has the best adsorption property with the adsorption rate of 97.17% at the optimal conditions as follows:the Mg-Al ra-tio of Mg-Al-G hydrotalcite is 2∶1,the dosage of Mg-Al-G hydrotalcite is 4.0000 g,the initial concentration of lead ion solution is 30 mg·L-1,the pH value of lead ion solution is 6,the adsorption time is 90 min,and the ad-sorption temperature is 20 ℃.%以硝酸镁和硝酸铝配制含镁铝离子的金属盐溶液,以谷氨酸溶于脱二氧化碳的去离子水中配制含谷氨酸的酸溶液,利用共沉淀方法,在 N2保护下将盐溶液与酸溶液混合、晶化后制备谷氨酸插层镁铝水滑石(Mg-Al-G),通过红外光谱和热重分析对其进行了表征,并研究了其对水中铅离子的吸附性能.结果表明,谷氨酸在 150 ℃脱羟基,在 250℃时分解,当谷氨酸成功插入水滑石层间后,水滑石的热稳定性更好;Mg-Al-G水滑石对水中铅离子具有较好的吸附性能,在 Mg-Al-G水滑石的镁铝比为 2∶1、Mg-Al-G水滑石用量为4.0000 g、铅离子溶液初始浓度为 30 mg·L-1、铅离子溶液 pH 值为 6、吸附时间为 90 min、吸附温度为 20 ℃的最佳条件下,Mg-Al-G水滑石对水中铅离子的吸附率达到 97. 17%.