Mobil Composition of Matter (MCM)-41 molecular sieve was successfully synthesized. Power X-ray diffraction, scanning electron microscopy and transmission electron microscopy (TEM) were used to characterize the sample. The sample showed spherical particles, and the morphology was regular. Its average particle diameter was 110 nm. TEM images showed that the sample structure presented a honeycomb pore structure and the average pore diameter was 3.5 nm. Pb²⁺ was adsorbed from water body by the MCM-41. The effects of acidity, contact time, temperature, adsorbent material amount and initial Pb²⁺ concentration on the adsorption rate were studied, and the optimum conditions of adsorption were obtained. The results show that when acidity pH value was 4.5, temperature was 25 °C, contact time was 40 min and the adsorbent material MCM-41/Pb²⁺ = 7.5, the adsorptive effect was the best, the adsorption rate reached 98.78% and the adsorptive capacity was 131.71 mg/g. Kinetic and thermodynamic properties of the adsorptive process were studied. Experimental results show that the adsorption of Pb²⁺ by MCM-41 belongs to the pseudo-second-order adsorption. According to thermodynamic equation, ΔG = ΔH − TΔS, ΔH = − 24.86 kJ/mol and ΔS = − 72.34 J/(mol K) were obtained by calculation, indicating that the adsorption was exothermic and an entropy reduction process. At the temperature of 298, 308 and 318 K, the free energy change was, respectively, ΔG₁ = − 3.286 kJ/mol, ΔG₂ = − 2.586 kJ/mol and ΔG₃ = − 1.86 kJ/mol, illustrating that at the above temperature the reaction can be carried on spontaneously. Nitric acid, hydrochloric acid and acetic acid were, respectively, used to investigate their effect on desorption. The results show that the desorption effect using nitric acid as a desorption agent was better than those of hydrochloric acid and acetic acid. When desorption was 5 h and the nitric acid concentration was 0.5 mol/l, the desorption rate was the highest that was reached 70.01%.

中文翻译：

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纳米介孔MCM-41用于去除水溶液中的Pb（II）

成功地合成了物质的分子组成（MCM）-41的分子筛。使用功率X射线衍射，扫描电子显微镜和透射电子显微镜（TEM）表征样品。样品显示球形颗粒，并且形态规则。其平均粒径为110nm。TEM图像显示样品结构呈现蜂窝状孔结构，平均孔径为3.5nm。Mb-41从水中吸收了Pb ²⁺。酸度，接触时间，温度，吸附剂含量和初始Pb ^2+的影响研究了吸附浓度对吸附速率的影响，并确定了最佳吸附条件。结果表明，在酸性pH值为4.5，温度为25°C，接触时间为40 min，吸附材料MCM-41 / Pb ²⁺  = 7.5的条件下，吸附效果最佳，吸附率达98.78％，吸附能力为131.71 mg / g。研究了吸附过程的动力学和热力学性质。实验结果表明，MCM-41对Pb ²⁺的吸附属于拟二级吸附。根据热力学方程，Δ ģ  =Δ ħ  -  Ť Δ小号，Δ ħ  = - 24.86千焦/摩尔和Δ小号 通过计算获得＝-72.34J /（mol K），表明吸附是放热的和熵降低的过程。在298、308和318 K的温度下，自由能变化分别为ΔG ₁  =  -3.286 kJ / mol，ΔG ₂ =-2.586 kJ / mol和ΔG ₃ ＝ -1.86kJ / mol，说明在上述温度下反应可以自发进行。分别使用硝酸，盐酸和乙酸研究其对解吸的影响。结果表明，硝酸作为解吸剂的解吸效果优于盐酸和乙酸。解吸时间为5 h，硝酸浓度为0.5 mol / l时，解吸率最高，达到70.01％。