Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, Hainan University, Haikou, 570100, China.
College of Science, Qiongtai Normal University, Haikou, 571127, China.
Environ Res. 2022 Nov;214(Pt 2):113827. doi: 10.1016/j.envres.2022.113827. Epub 2022 Jul 19.
Adsorption of lead as Pb(II) using biochar is an environmentally sustainable approach to remediate this kind of pollution affecting wastewater. In this study, rice straw biochar (BC) was modified by combination with nano-hydroxy-apatite (HAP), resulting in a material designated as BC@nHAP, with enhanced adsorption performance. Based on Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses, it was evidenced that, after modification, HAP greatly enhanced surface functional groups (i.e., -COOH and/or -OH) of raw biochar's surface. Batch tests showed that the maximum sorption capacity of BC (63.03 mg g) was improved due to the modification, reaching 335.88 mg g in BC@nHAP. Pseudo-second order (PSO) kinetics fitted well the adsorption data (R = 0.99), as well as the Langmuir isotherm model (showing an adsorption value of 335.88 mg g for q). The results of thermodynamic calculations showed that the adsorption was primarily governed by chemisorption process. FTIR spectroscopy and XPS spectrum after adsorption further confirmed that the adsorption mechanisms were ion exchange with Pb and surface complexation by -OH and -COOH. In addition, BC@nHAP revealed a brilliant regeneration capability. The maximum adsorption capacity by BC@nHAP was higher than that of raw biochar or other previously reported adsorbents. Therefore, BC@nHAP could be seen as a new sorbent material with high potential for real-scale heavy metal removal from wastewater, and specifically as a capable candidate new sorbent for Pb(II) removal from wastewater, which has clear implications as regard preservation of environmental quality and public health.
使用生物炭吸附 Pb(II)是一种环境可持续的方法,可用于修复受污染的废水。在这项研究中,水稻秸秆生物炭(BC)通过与纳米羟基磷灰石(HAP)结合进行改性,得到了一种名为 BC@nHAP 的材料,其吸附性能得到了增强。通过傅里叶变换红外光谱(FTIR)、X 射线衍射(XRD)和 X 射线光电子能谱(XPS)分析表明,改性后,HAP 极大地增强了原始生物炭表面的官能团(即-COOH 和/或-OH)。批量实验表明,由于改性,BC 的最大吸附容量(63.03mg/g)得到了提高,在 BC@nHAP 中达到 335.88mg/g。准二级动力学(PSO)很好地拟合了吸附数据(R=0.99),以及 Langmuir 等温模型(表现出 335.88mg/g 的吸附值 q)。热力学计算结果表明,吸附主要受化学吸附过程控制。吸附后的 FTIR 光谱和 XPS 谱进一步证实了吸附机制是 Pb 的离子交换和 -OH 和 -COOH 的表面络合。此外,BC@nHAP 表现出出色的再生能力。BC@nHAP 的最大吸附容量高于原始生物炭或其他先前报道的吸附剂。因此,BC@nHAP 可以被视为一种新型吸附剂,具有从废水中去除重金属的高潜力,特别是作为一种从废水中去除 Pb(II)的有能力的新型吸附剂,对保护环境质量和公共健康具有明确的意义。
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