School of Chemistry and Chemical Engineering, Queen's University Belfast, David Kier Building, BT9 5AG, United Kingdom.
School of Chemistry and Chemical Engineering, Queen's University Belfast, David Kier Building, BT9 5AG, United Kingdom.
J Environ Manage. 2024 Aug;366:121682. doi: 10.1016/j.jenvman.2024.121682. Epub 2024 Jul 10.
In this research, spent coffee grounds (SCG) are converted into a highly valuable porous adsorbent which removes chromium (VI) from wastewater with high efficiency. A set of nine Spent Coffee Ground Activated Carbon (SCG-AC) adsorbent samples were synthesized, by varying key parameters including pyrolysis temperature (400, 600 °C), pyrolysis duration (1 and 2 h), and the impregnation ratio of the activating agent, KOH (ranging from 0:1 to 2:1). Characterizations of these adsorbent samples were conducted by advanced analytical tools including SEM, EDX, XRD, FTIR, TGA, and BET. Furthermore, we carried out adsorption studies, exploring the effects of temperature and dosage variations. Additionally, point zero charge experiments and desorption studies were carried out to further understand the adsorption process. The outcomes of our investigation demonstrate the successful synthesis of these spent coffee ground-derived adsorbents, with a yield of up to 34%. Notably, these adsorbents exhibited high efficiency in extracting chromium (VI) from water, with removal efficiencies ranging from 75% to 100%. The adsorption isotherms revealed the Langmuir model to be the most fitting descriptor of the adsorption behavior. Moreover, a thermodynamics study revealed the process to be endothermic in nature which furthers our understanding of the underlying mechanisms. Importantly, our cost assessment shows the economic advantage of the synthesized adsorbent over commercial counterparts such as zeolite, making it a competitive choice for real-world applications. In summation, the study not only introduces an innovative and sustainable utilization of spent coffee grounds but also delivers an in-depth exploration of the synthesized adsorbent's ability in chromium (VI) removal. Our holistic approach, encompassing thorough experimentation, characterization, and economic evaluation, solidifies the significance of this research in tackling environmental concerns and propelling advancements in wastewater treatment methodologies.
在这项研究中，用过的咖啡渣（SCG）被转化为一种极具价值的多孔吸附剂，可高效去除废水中的六价铬（VI）。通过改变关键参数，包括热解温度（400、600°C）、热解时间（1 和 2 小时）和活化剂 KOH 的浸渍比（0:1 至 2:1），合成了九组用过的咖啡渣活性炭（SCG-AC）吸附剂样品。通过先进的分析工具，包括 SEM、EDX、XRD、FTIR、TGA 和 BET，对这些吸附剂样品进行了表征。此外，我们进行了吸附研究，探讨了温度和剂量变化的影响。此外，还进行了零点电荷实验和脱附研究，以进一步了解吸附过程。我们的研究结果表明，成功合成了这些基于用过的咖啡渣的吸附剂，产率高达 34%。值得注意的是，这些吸附剂在从水中提取六价铬方面表现出很高的效率，去除效率范围为 75%至 100%。吸附等温线表明，Langmuir 模型最适合描述吸附行为。此外，热力学研究表明该过程本质上是吸热的，这进一步加深了我们对潜在机制的理解。重要的是，我们的成本评估表明，与沸石等商业对照物相比，合成吸附剂具有经济优势，使其成为实际应用的一种有竞争力的选择。总之，该研究不仅介绍了一种创新且可持续的利用用过的咖啡渣的方法，还深入探讨了合成吸附剂去除六价铬的能力。我们的综合方法包括全面的实验、表征和经济评估，巩固了这项研究在解决环境问题和推动废水处理方法进步方面的重要性。
