| 污泥生物炭硼掺杂改性及其对水中1,2-二氯乙烷吸附行为和机制 |
| 摘要点击 1400 全文点击 1296 投稿时间：2022-06-24 修订日期：2022-07-30 |
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| 中文关键词 污泥生物炭(BC600) 硼掺杂 1,2-二氯乙烷(1,2-DCA) 吸附动力学 吸附机制 |
| 英文关键词 sludge biochar(BC600) B-doped 1,2-DCA adsorption kinetics adsorption mechanism |
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| 中文摘要 |
| 以市政污泥为前驱体，采用硼酸掺杂改性共热解法，制备了污泥生物炭（BC600）和B掺杂污泥生物炭（BBC600），采用SEM、BET、FTIR、Zeta电位和静态接触角等手段对材料进行了结构表征，研究了BC600和BBC600对水中1，2-二氯乙烷（1，2-DCA）的吸附行为、机制和影响因素.结构表征结果表明，B掺杂改性后，生物炭中B元素含量、比表面积和孔容分别提高了76%、48%和30%；B掺杂改性对生物炭表面电荷及亲疏水性影响不大，BC600和BBC600表面均带有负电荷，接触角均<90°，两者均具有较好的亲水性.吸附实验结果表明，BBC600对1，2-DCA的吸附性能优于BC600，缘于BBC600更大的比表面积和强度更高的含氧官能团；准一级动力学方程可以较好描述BC600吸附1，2-DCA过程，准二级动力学方程能较好拟合BBC600吸附1，2-DCA过程，颗粒内扩散不是影响吸附速率的唯一限速步骤；碱性条件下生物炭材料更加分散和稳定，且其含氧官能团去质子化，供电子能力增强，有利于对1，2-DCA的吸附；腐殖酸（HA）对BC600吸附1，2-DCA呈现低浓度促进，高浓度抑制的作用，而低浓度和高浓度的HA对BBC600吸附1，2-DCA均呈抑制作用，HA会与1，2-DCA发生竞争吸附；Cl-、SO42-和NO3-均对生物炭吸附1，2-DCA具有抑制作用，抑制程度由小到大为：Cl-42-3-.生物炭吸附1，2-DCA主要机制为孔隙填充和π-π作用. |
| 英文摘要 |
| Sludge biochar (BC600) and B-doped sludge biochar (BBC600) were prepared with the boric acid doping modified co-pyrolysis method using municipal sludge as precursors, and the materials were structurally characterized by SEM, BET, FTIR, and Zeta potential and static contact angle to investigate the adsorption behavior, mechanism of BC600 and BBC600 on 1,2-DCA in water, and the influencing factors. The results of structural characterization showed that the B element content, specific surface area, and pore volume of biochar increased by 76%, 48%, and 30%, respectively, after the B doping modification; the effect of B doping modification on the surface charge and hydrophobicity of biochar was not significant. The results of adsorption experiments showed that the adsorption of 1,2-DCA by BBC600 was better than that by BC600 due to the larger specific surface area and higher strength of oxygen-containing functional groups of BBC600; the pseudo-first-order kinetic equation could better describe the adsorption of 1,2-DCA by BC600, and the pseudo-second-order kinetic equation could better fit the adsorption of 1,2-DCA by BBC600. The intraparticle diffusion was not the only rate-limiting step affecting the adsorption rate; the biochar material was more dispersed and stable under alkaline conditions, and its oxygen-containing functional groups were deprotonated and had enhanced electron-donating ability, which was beneficial to the adsorption of 1,2-DCA. Humic acid (HA) showed a low concentration-promoting and high concentration-inhibiting effect on the adsorption of 1,2-DCA by BC600, whereas both low and high concentrations of HA showed an inhibitory effect on the adsorption of 1,2-DCA by BBC600. The adsorption of 1,2-DCA by BC600 was inhibited by both low and high concentrations of HA, and HA competed with 1,2-DCA for adsorption; Cl-, SO42-, and NO3- all inhibited the adsorption of 1,2-DCA by biochar, and the degree of inhibition ordered from small to large was Cl-42-3-. The main mechanisms of 1,2-DCA adsorption by biochar were pore filling and π-π interaction. |
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