Tayyab Muhammad, Anwar Sumera, Shafiq Fahad, Shafique Umer, Kaya Cengiz, Ashraf Muhammad
Department of Botany, Institute of Molecular Biology and Biotechnology, The University of Lahore, Pakistan.
Department of Botany, Government College Women University, Faisalabad, Pakistan.
Int J Phytoremediation. 2025;27(2):244-259. doi: 10.1080/15226514.2024.2412820. Epub 2024 Oct 15.
Removal of Cd(II) and Pb(II) from aqueous solutions is a challenging task and the search for novel adsorbents is underway. This study examined the efficiency of nanobiochar (NB) and rice husk (RH) in the adsorption and removal of Cd(II) and Pb(II) from water. The effect of various physicochemical parameters such as initial pH, initial Cd and Pb concentration, adsorbent dosage, and contact time were tested. SEM/EDX images confirmed the adsorption of Pb and Cd with surface physical and chemical changes. The maximum Pb removal was noted at pH 6 using NB (96%) and at pH 8 for RH (90%), and the maximum Cd removal by NB was recorded at 8 pH (91%) and by RH at pH 6 (87%). The decline in adsorption intensity at lower pH suggested protonation of the adsorbent surface causing cation-cation repulsion. Most of the adsorption occurred within the initial 60 min. A continuous gradual increase in the adsorption with time suggested multilayer formation. Of the three isotherms, the Freundlich model fits the present data best, implying an infinite surface coverage and indicating the potential for multilayer adsorption of Pb and Cd on the surfaces of RH and NB adsorbents. In conclusion, this study highlights the promising potential of NB as a cost-effective adsorbent for the removal of Cd and Pb ions from aqueous solutions.
从水溶液中去除镉（II）和铅（II）是一项具有挑战性的任务，目前正在寻找新型吸附剂。本研究考察了纳米生物炭（NB）和稻壳（RH）对水中镉（II）和铅（II）的吸附和去除效率。测试了各种物理化学参数的影响，如初始pH值、初始镉和铅浓度、吸附剂用量和接触时间。扫描电子显微镜/能谱（SEM/EDX）图像证实了铅和镉的吸附伴随着表面物理和化学变化。使用NB时，在pH值为6时铅的去除率最高（96%），使用RH时，在pH值为8时铅的去除率最高（90%）；使用NB时，在pH值为8时镉的去除率最高（91%），使用RH时，在pH值为6时镉的去除率最高（87%）。较低pH值下吸附强度的下降表明吸附剂表面质子化导致阳离子-阳离子排斥。大多数吸附发生在最初的60分钟内。吸附量随时间持续逐渐增加表明形成了多层结构。在三种等温线中，弗伦德利希模型最适合当前数据，这意味着表面覆盖率无限，表明铅和镉在RH和NB吸附剂表面有多层吸附的潜力。总之，本研究突出了NB作为一种经济高效的吸附剂从水溶液中去除镉和铅离子的广阔前景。
