School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
J Hazard Mater. 2020 Jan 15;382:121048. doi: 10.1016/j.jhazmat.2019.121048. Epub 2019 Aug 20.
Million tons of sewage sludge produced yearly creates a severe pollution problem to environment, and thus needs either to be properly disposed of, or recovered. Here, we demonstrate a value-added utilization of sewage sludge by converting its contained organics into nanosized carbon dots (CDs) with microwave irradiation. This synthetic method, using waste resources as precursors and avoiding the requirement of hazardous reagents and complex procedures, has the great advantage of low cost, environmental friendliness, and easy scalability. The resultant CDs exhibit excellent fluorescence properties with a large quantum yield (QY) of up to 21.7%, higher than the most values of waste-derived CDs. It is found that CDs can serve as a sensitive and selective sensor to detect para-Nitrophenol (p-NP), a toxic pollutant, through fluorescence quenching, giving a linear detection range of 0.2-20 μM and a detection limit of as low as 0.069 μM. Systematic investigations suggest that the inner filter effect (IFE) is the dominant sensing mechanism. Moreover, the practical applications of CDs for p-NP assay in real water samples achieve good results.
每年产生的百万吨污水污泥对环境造成了严重的污染问题，因此需要进行妥善处理或回收。在这里，我们通过微波辐射将污水污泥中的有机物转化为纳米级碳点（CDs），展示了一种污水污泥的增值利用方法。这种合成方法以废物资源为前体，避免了使用危险试剂和复杂程序的要求，具有低成本、环保和易于扩展的巨大优势。所得的 CDs 具有优异的荧光性质，量子产率高达 21.7%，高于大多数废物衍生的 CDs 的值。研究发现，CDs 可以作为一种灵敏和选择性的传感器，通过荧光猝灭来检测对硝基苯酚（p-NP），这是一种有毒污染物，其线性检测范围为 0.2-20 μM，检测限低至 0.069 μM。系统的研究表明，内滤效应（IFE）是主要的传感机制。此外，CDs 在实际水样中的 p-NP 测定中的实际应用取得了良好的效果。
