A series of hydrophobic and hydrophilic amino acid (aspartic acid, phenylalanine, glutamic acid, and proline) intercalated LDH materials were synthesized and characterized. The results of batch experiments showed that Mg₇Zn₁Fe₄-Asp-LDH and Mg₇Zn₁Fe₄-Phe-LDH showed good adsorption performances for both arsenate and arsenite in aqueous solutions. The effects of various experimental conditions have been investigated by the batch test, which included the effects of initial pH, arsenic concentration, contact time and coexisting ions. For Mg₇Zn₁Fe₄-Asp-LDH under the optimal experimental conditions, the maximum adsorption capacity of As(III) and As(V) reached 94.81 mg g⁻¹ and 57.42 mg g⁻¹, respectively. It showed a higher adsorption capacity for As(III) than that for As(V), which is of great significance to remove the trivalent arsenic species with higher toxicity. When the dosage of Mg₇Zn₁Fe₄-Asp-LDH was 0.8 g L⁻¹, the concentration of As(III) in the aqueous solution could be reduced from 2 mg L⁻¹ to below 10 μg L⁻¹.When Mg-Zn-Fe-Asp-LDH was applied in practical water samples with a dosage of 0.2 g L⁻¹, the residual concentrations of arsenic in three actual water samples were all lower than 10 μg L⁻¹ after adsorption. The column test showed that 1.0 g of Mg₇Zn₁Fe₄-Asp-LDH could continuously treat 2.6 L of As(III) aqueous solution (2 mg L⁻¹) and reduced the concentration of As(III) to below 10 μg L⁻¹ or handle 0.4 L of arsenic-contaminated (10 mg L⁻¹, As(III) : As(V) = 1 : 1) water, and the effluent concentration was below 10 μg L⁻¹. Compared with the previously reported hydrophobic amino acid intercalated LDHs, aspartic acid (hydrophilic amino acid) intercalated LDH has a good removal efficiency for arsenic. The synthesized Mg₇Zn₁Fe₄-Asp-LDH is considered to be a potentially functional material that can be used to treat arsenic contamination in water.

中文翻译：

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天冬氨酸插层Mg-Zn-Fe-LDH材料对砷的吸附性能增强†

合成并表征了一系列疏水和亲水氨基酸（天冬氨酸，苯丙氨酸，谷氨酸和脯氨酸）插入的LDH材料。分批实验结果表明，Mg ₇ Zn ₁ Fe ₄ -Asp-LDH和Mg ₇ Zn ₁ Fe ₄ -Phe-LDH在水溶液中对砷酸盐和亚砷酸盐均表现出良好的吸附性能。通过分批测试研究了各种实验条件的影响，包括初始pH，砷浓度，接触时间和共存离子的影响。对于Mg ₇ Zn ₁ Fe ₄-Asp-LDH在最佳实验条件下，As（III）和As（V）的最大吸附容量分别达到94.81 mg g ^-1和57.42 mg g ^-1。它对砷（Ⅲ）的吸附能力高于对砷（Ⅴ）的吸附能力，这对于去除毒性较高的三价砷具有重要意义。当Mg ₇ Zn ₁ Fe ₄ -Asp-LDH的剂量为0.8 g L ^-1时，水溶液中As（III）的浓度可以从2 mg L ^-1降至10μgL ^-1以下。当将Mg-Zn-Fe-Asp-LDH以0.2 g L ^-1的量应用于实际水样中时，三个实际水样中砷的残留浓度在吸附后均低于10μgL ^-1。柱试验表明，1.0 g Mg ₇ Zn ₁ Fe ₄ -Asp-LDH可以连续处理2.6 L的As（III）水溶液（2 mg L ^-1），并将As（III）的浓度降低至10μg以下L ^-1或处理0.4 L的砷污染（10 mg L ^-1，As（III）：As（V）= 1：1）水，且废水浓度低于10μgL^-1。与先前报道的疏水性氨基酸插层的LDH相比，天冬氨酸（亲水性氨基酸）插层的LDH对砷具有良好的去除效率。合成的Mg ₇ Zn ₁ Fe ₄ -Asp-LDH被认为是可以用于处理水中砷污染的潜在功能材料。