Murtaza Behzad, Naseer Aqsa, Imran Muhammad, Shah Noor S, Al-Kahtani Abdullah A, ALOthman Zeid A, Shahid Muhammad, Iqbal Jibran, Abbas Ghulam, Natasha Natasha, Amjad Muhammad
Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Vehari, 61100, Pakistan.
Department of Chemistry, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia.
Environ Geochem Health. 2023 Dec;45(12):9003-9016. doi: 10.1007/s10653-023-01630-8. Epub 2023 Jun 2.
Chromium (Cr), due to its greater contamination in aquifers and distinct eco-toxic impacts, is of greater environmental concern. This study aimed to synthesize nanocomposites of almond shells biochar (BC) with zerovalent bismuth and/or copper (Bi/BC, Cu/BC, and Bi-Cu/BC) for the removal of Cr from aqueous solution. The synthesized nanocomposites were investigated using various characterization techniques such as XRD, FTIR spectroscopy, SEM, and EDX. The Cr removal potential by the nanocomposites was explored under different Cr concentrations (25-100 mg/L), adsorbent doses (0.5-2.0 g/L), solution pH (2-8), and contact time (10-160 min). The above-mentioned advanced techniques verified successful formation of Bi/Cu and their composite with BC. The synthesized nanocomposites were highly effective in the removal of Cr. The Bi-Cu/BC nano-biocomposites showed higher Cr removal efficiency (92%) compared to Cu/BC (85%), Bi/BC (76%), and BC (67%). The prepared nanocomposites led to effective Cr removal at lower Cr concentrations (25 mg/L) and acidic pH (4.0). The Cr solubility changes with pH, resulting in different degrees of Cr removal by Bi-Cu/BC, with Cr(VI) being more soluble and easier to adsorb at low pH levels and Cr(III) being less soluble and more difficult to adsorb at high pH levels. The experimental Cr adsorption well fitted with the Freundlich adsorption isotherm model (R > 0.99) and pseudo-second-order kinetic model. Among the prepared nanocomposites, the Bi-Cu/BC showed greater stability and reusability. It was established that the as-synthesized Bi-Cu/BC nano-biocomposite showed excellent adsorption potential for practical Cr removal from contaminated water.
铬（Cr）因其在含水层中的污染程度较高以及独特的生态毒性影响，而备受环境关注。本研究旨在合成杏仁壳生物炭（BC）与零价铋和/或铜的纳米复合材料（Bi/BC、Cu/BC和Bi-Cu/BC），用于从水溶液中去除铬。使用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和能谱分析（EDX）等各种表征技术对合成的纳米复合材料进行了研究。在不同的铬浓度（25 - 100毫克/升）、吸附剂剂量（0.5 - 2.0克/升）、溶液pH值（2 - 8）和接触时间（10 - 160分钟）条件下，探究了纳米复合材料对铬的去除潜力。上述先进技术证实了Bi/Cu及其与BC复合材料的成功形成。合成的纳米复合材料对铬的去除效果显著。与Cu/BC（85%）、Bi/BC（76%）和BC（67%）相比，Bi-Cu/BC纳米生物复合材料显示出更高的铬去除效率（92%）。制备的纳米复合材料在较低的铬浓度（25毫克/升）和酸性pH值（4.0）下能有效去除铬。铬的溶解度随pH值变化，导致Bi-Cu/BC对铬的去除程度不同，其中Cr(VI)在低pH值下更易溶解且更易吸附，而Cr(III)在高pH值下溶解度较低且更难吸附。实验得到的铬吸附结果与Freundlich吸附等温线模型（R＞0.99）和准二级动力学模型拟合良好。在所制备的纳米复合材料中，Bi-Cu/BC表现出更高的稳定性和可重复使用性。已证实，合成的Bi-Cu/BC纳米生物复合材料在实际去除受污染水中的铬方面具有优异的吸附潜力。
