不同生物质组分对铁碳微电解材料制备及As(Ⅲ)去除效率的影响

以湿地植物芦苇、还原铁粉和膨润土为原材料，通过“均质化—碳化—焙烧”工艺，制备用于去除水体中As(Ⅲ)的植物基铁碳微电解材料，对其采用傅里叶红外光谱(FIR)、元素分析、X射线衍射分析及热重差热综合热分析(TGA)等方法进行系统表征，结合响应面优化研究对比得到不同植物基生物质前驱体(芦苇秆和芦苇叶)的不同组分(半纤维素、纤维素和木质素)对植物基铁碳微电解材料性能的影响。通过响应面模型获得的优化制备条件为：芦苇秆植物基铁碳微电解材料为Fe/C=1.06、碳化温度507.87 ℃、焙烧温度751.92 ℃，芦苇叶植物基铁碳微电解材料为Fe/C=1.01、碳化温度498.66 ℃、焙烧温度701.09 ℃，在此条件下5 g制备得到的材料对100 mL 10 mg·L⁻¹ NaAsO₂去除率分别为98.12%和97.22%。结果表明：在植物基生物质前驱体的不同组分中，纤维素和半纤维素含量越高，较低的碳化和焙烧温度能降低材料中灰分含量，提高有效碳元素质量分数，增加微原电池数量；木质素含量越高，高焙烧温度下，氧化及电子传递能力越强，有利于As(Ⅲ)转化为As(Ⅴ)，从而提高As(Ⅲ)的去除效率。

Effects of different biomass components on the preparation of Fe-C microelectrolytic materials and As(III) removal efficiency

A plant-based iron carbon microelectrolysis material for removing As(III) from water was prepared by using reed, reduced iron powder and bentonite as raw materials through a homogenization-carbonization-roasting process. It was characterized by Fourier transform infrared spectroscopy (FTIR), Elemental analysis, X-ray diffraction (XRD) and Thermogravimetric differential thermal synthesis (TGA). The effects of different components (hemicellulose, cellulose and lignin) of different plant-based biomass precursors (reed stalk and reed leaf) on the properties of plant-based Fe-C microelectrolytic materials were compared by response surface optimization. The optimal preparation conditions obtained by response surface model were as follows: Fe/C of 1.06, carbonization temperature of 507.87 ℃ and roasting temperature of 751.92 ℃; Fe/C of 1.01, carbonization temperature of 498.66 ℃ and roasting temperature of 701.09 ℃. The removal rates of 100 mL 10 mg·L−1 NaAsO2 by 5 g material based on above two conditions were 98.12% and 97.22%, respectively. The results showed that in different components of plant-based biomass precursors, the higher the content of cellulose and hemicellulose, the lower the carbonization and calcination temperature, as well as the lower the ash content, the higher the effective carbon content, and the higher the number of microgalvanic cells. The higher the lignin content is, the stronger the oxidation and electron transfer capacity is at high roasting temperature, which was conducive to the conversion of As (Ⅲ) to As (Ⅴ) and the improvement of As (Ⅲ) removal efficiency.