School of Medicine and Pharmacy, Duy Tan University, Da Nang, Viet Nam; Institute of Research and Development, Duy Tan University, Da Nang, Viet Nam.
School of Medicine and Pharmacy, Duy Tan University, Da Nang, Viet Nam; Institute of Research and Development, Duy Tan University, Da Nang, Viet Nam.
Chemosphere. 2023 Dec;343:140076. doi: 10.1016/j.chemosphere.2023.140076. Epub 2023 Sep 5.
Polycyclic aromatic hydrocarbons (PAHs) are omnipresent, persistent, and carcinogenic pollutants continuously released in the atmosphere due to the rapid increase in population and industrialization worldwide. Hence, there is an ultimate rise in concern about eliminating the toxic PAHs and their related aromatic hydrocarbons from the air, water, and soil environment by employing efficient removal technologies using nanoparticles as a catalyst. Here, the degradation of selective PAHs viz., anthracene and benzene using laboratory synthesized rGO-Ag-Cu-Ni nanocomposite (catalyst) was studied. Characterization studies revealed the nanocomposites exhibited surface plasma resonance at 350 - 450 nm, confirming the presence of Ag, Cu, and Ni metal ions embedded on the reduced graphene substrate. It was found that the nanocomposites synthesized were spherical, amorphous in nature, and aggregated together with measurements ranging from 423 to 477 nm. An SEM-EDX analysis of the nanocomposite demonstrated that it contained 25.13% O, 14.24% Ni, 27.79% Cu, and 32.84% Ag, which confirms the synthesis of the nanocomposite. Crystalline, sharp nanocomposites of average size 17-41 nm with an average diameter of 118.5 nm (X-ray diffraction and DLS) were observed. FTIR spectra showed that the nanocomposites had the functional groups alkanes, alkenes, alkynes, carboxylic acids, and halogen derivatives. Batch adsorption studies revealed that the maximum degradation achieved at optimum nano-composite concentration of 10 μg/mL, pH value of 5, PAHs concentration of 2 μg/mL and effective irradiation source being UV radiations in the case of both benzene and anthracene pollutants. The degradation of benzene and anthracene followed Freundlich & Langmuir isotherm with the highest R value of 0.9894 & 0.9885, respectively. Adsorption kinetic studies under optimum conditions revealed that the adsorption of both benzene and anthracene followed Pseudo-second order kinetics. Antimicrobial studies revealed that the synthesized nano-composite exhibited potential antimicrobial activity against Gram positive bacterium (Bacillus subtilis, Staphylococcus aureus), Gram negative bacterium (Klebsiella pneumonia, Escherichia coli) and fungal strain (Aspergillus niger) respectively. Thus, the synthesized rGO-Ag-Cu-Ni nano-composite acts as an effective antimicrobial agent as well as a PAHs degrading agent, helping to overcome antibiotics resistance and to mitigate the overgrowing PAHs pollution in the environment.
多环芳烃（PAHs）是无处不在、持久存在且具有致癌性的污染物，由于世界范围内人口和工业化的快速增长，它们不断被释放到大气中。因此，人们越来越关注采用纳米颗粒作为催化剂的高效去除技术，从空气、水和土壤环境中消除有毒的 PAHs 及其相关芳烃。在这里，使用实验室合成的 rGO-Ag-Cu-Ni 纳米复合材料（催化剂）研究了选择的 PAHs 蒽和苯的降解。表征研究表明，纳米复合材料在 350-450nm 处表现出表面等离子体共振，证实了还原氧化石墨烯衬底上存在嵌入的 Ag、Cu 和 Ni 金属离子。研究发现，合成的纳米复合材料为球形，本质上是非晶态的，并聚集在一起，粒径范围为 423-477nm。纳米复合材料的 SEM-EDX 分析表明，它含有 25.13%的 O、14.24%的 Ni、27.79%的 Cu 和 32.84%的 Ag，这证实了纳米复合材料的合成。观察到平均尺寸为 17-41nm 的结晶、尖锐的纳米复合材料，平均直径为 118.5nm（X 射线衍射和 DLS）。FTIR 光谱表明，纳米复合材料具有烷烃、烯烃、炔烃、羧酸和卤代衍生物等官能团。批量吸附研究表明，在最佳纳米复合材料浓度为 10μg/mL、pH 值为 5、PAHs 浓度为 2μg/mL 且有效辐照源为苯和蒽污染物的情况下，UV 辐射下最大降解率达到 10μg/mL。苯和蒽的降解遵循 Freundlich 和 Langmuir 等温线，最高 R 值分别为 0.9894 和 0.9885。在最佳条件下进行的吸附动力学研究表明，苯和蒽的吸附均遵循拟二级动力学。抗菌研究表明，合成的纳米复合材料对革兰氏阳性菌（枯草芽孢杆菌、金黄色葡萄球菌）、革兰氏阴性菌（肺炎克雷伯菌、大肠杆菌）和真菌（黑曲霉）均表现出潜在的抗菌活性。因此，合成的 rGO-Ag-Cu-Ni 纳米复合材料不仅是一种有效的 PAHs 降解剂，还具有抗菌作用，有助于克服抗生素耐药性并减轻环境中日益严重的 PAHs 污染。
