| dc.description.abstract | Environmental protection and water quality monitoring are one of the important issues facing today′s society. The detection of chemical oxygen demand (COD) is crucial for assessing the content of organic pollutants in water bodies. Traditional COD analysis methods still have many shortcomings, such as long analysis time, limited oxidation capacity, and secondary pollution from toxic reagents. The electrochemical method not only has the advantages of rapid analysis, high sensitivity, and environmental friendliness, but can also be applied to on-site monitoring and analysis, making it gradually attract attention.
In this study, titanium dioxide/single-walled carbon nanotube composites were prepared by the sol-gel method and used to modify screen-printed electrodes (SPE). Linear scan voltammetry (LSV) was used under optimal scanning conditions (the electrolyte was 0.1 M sodium chloride buffer solution, COD analysis of water samples, including simulated water samples and real water samples, is performed at a scanning speed of 0.15 V s–1). Among them, simulated water samples are divided into single water samples and composite water samples. The selected organic substances include: potassium hydrogen phthalate, glucose, ethanolamine, salicylic acid, and dimethylformamide. The theoretical oxygen demand (ThOD) linear range is between 20–100 mg L–1. In addition, three of the organic compounds were mixed into composite water samples in different proportions to explore the interaction between the organic compounds. The results showed that the peak current analyzed and ThOD showed a positive correlation. For the reproducibility analysis of the modified electrode, the relative standard deviation was 4.93%. For real water samples, the prepared modified electrode was used to measure the discharge water from the sewage treatment plant in Pingzhen Industrial Zone. The results showed that the good linear characteristics made its application in real water samples more practical. Therefore, it is confirmed that the TiO2/SWCNT/SPE has good potential in COD measurement, making it have broad application prospects in environmental monitoring, water quality management, and related fields. | en_US |