不同热解温度牛骨生物炭特征及对Cd<sup>2+</sup>的吸附

黄涛; 胡林潮; 吴佳楠; 张文艺; 毛林强

文章摘要

黄涛,胡林潮,吴佳楠,张文艺,毛林强.不同热解温度牛骨生物炭特征及对Cd²⁺的吸附[J].农业环境科学学报,2023,42(7):1632-1644.

不同热解温度牛骨生物炭特征及对Cd²⁺的吸附

Characteristics of bovine bone biochar at different pyrolysis temperatures and its adsorption of Cd²⁺

投稿时间：2023-01-19

DOI：10.11654/jaes.2023-0045

中文关键词: 牛骨生物质炭吸附动力学吸附等温线 Cd²⁺

英文关键词: bovine bone biochar adsorption kinetics adsorption isotherm Cd²⁺

基金项目:国家自然科学基金项目（41403095）

作者	单位	E-mail
黄涛	常州大学环境科学与工程学院, 江苏常州 213164
胡林潮	常州大学环境科学与工程学院, 江苏常州 213164	hulc@cczu.edu.cn
吴佳楠	常州大学环境科学与工程学院, 江苏常州 213164
张文艺	常州大学环境科学与工程学院, 江苏常州 213164
毛林强	常州大学环境科学与工程学院, 江苏常州 213164

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中文摘要:

本文研究了不同热解温度条件下牛骨生物炭理化性质及对 Cd²⁺的吸附特性，采用限氧控温慢速热裂解的方式，在 300、350、400、500、700 ℃和900 ℃条件下制备牛骨生物炭。分别采用热重分析仪、傅里叶变换红外光谱以及扫描电镜能谱仪等设备对牛骨生物炭进行表征，并通过批量吸附实验分析其对Cd²⁺的吸附特性。结果表明：牛骨生物炭pH值、灰分含量随热解温度提高而增加，芳构度逐渐增强，孔径与比表面积增大，而挥发分、有机碳含量与全氮含量减少；准二级动力学模型可以准确拟合5种牛骨生物炭对Cd²⁺的吸附动力学过程（R²>0.999），在接近吸附平衡时，吸附速率由颗粒内扩散主导；牛骨生物炭对Cd²⁺等温吸附过程更符合Langmuir模型，700 ℃条件下制备的牛骨生物炭对Cd²⁺的吸附效果最好，最大平衡吸附量为44.32 mg·g^-1；随着热解温度增加，牛骨生物炭对Cd²⁺吸附机制中官能团络合作用减弱，表面吸附、阳离子交换以及π电子配位作用增大。在实际规模化制备牛骨生物炭过程中应充分考虑能耗成本以及尾气收集问题。

英文摘要:

Here, the physicochemical properties of bovine bone biochar and its adsorption properties for Cd²⁺ at different pyrolysis temperatures were studied. Bovine bone biochar was prepared at 300, 350, 400, 500, 700, and 900 ℃ using waste bovine bone as the raw material and the method of slow pyrolysis with limited oxygen at a controlled temperature. The bovine bone biochar was characterized by thermogravimetric analysis（TG）, Fourier transform infrared spectroscopy（FTIR）, and scanning electron microscopy（SEM）, and its Cd²⁺ adsorption characteristics were analyzed using batch adsorption experiments. The results showed that the pH value and ash content of bovine bone biochar increased with increasing pyrolysis temperature, simultaneously the aromatics gradually strengthened, and the pore size and specific surface area increased, but the contents of volatile matter, organic carbon, and total nitrogen decreased. The pseudosecond order kinetics model could accurately fit the adsorption kinetics of Cd²⁺ for the five bovine bone biochar species（R²>0.999）, and the adsorption rate was dominated by intra-particle diffusion near the adsorption equilibrium. The Cd²⁺ isothermal adsorption process of bovine bone biochar was consistent with the Langmuir model. Bovine bone biochar prepared at 700 ℃ showed the best adsorption effect on Cd²⁺ and the maximum equilibrium adsorption capacity was 44.32 mg·g^-1. With the increase in pyrolysis temperature, the complexation of functional groups in the Cd²⁺ adsorption mechanism of bovine bone biochar was weakened, whereas the surface adsorption, cation exchange, and π electron coordination effects increased. Our results suggest that energy consumption costs and tail gas collection should be fully considered in the process of preparing bovine bone biochar on a practical scale.

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