Periyasamy Selvendiran, Muthuchamy Muthukumar
a Environmental Engineering and Technology Laboratory, Department of Environmental Sciences , Bharathiar University , Coimbatore , India.
b Department of Environmental Science , Central University of Kerala , Kasaragod , India.
Environ Technol. 2018 Sep;39(18):2373-2381. doi: 10.1080/09593330.2017.1355932. Epub 2017 Oct 4.
In this study, the electrochemical degradation of caffeine (1,3,7-trimethylxanthine) in aqueous solution by a graphite electrode was investigated. Electrochemical degradation was tested by the cyclic voltametry technique performed in the potential range of -1.0 to +1.0 V versus Ag/AgCl, which confirmed the electro-activity of the selected caffeine. The effects of the treatment process variables, such as initial pH, current density, electrolyte concentration and electrolysis time on the degradation of caffeine, were explored. During the various stages of electrolysis, parameters such as chemical oxygen demand (COD), total organic carbon (TOC) were analysed. The maximum COD and TOC removal efficiencies of 85% and 77% were achieved at neutral pH 7, operated at a current density of 5.1 mA/cm, electrolyte (NaSO) concentration of 0.1 M and at 240 min electrolysis time. From this study, it can be concluded that the electrochemical treatment process could effectively reduce the COD and TOC from the caffeine in aqueous medium. The degradation of the caffeine was confirmed by UV spectra, IR spectra and HPLC analysis.
在本研究中，研究了用石墨电极对水溶液中咖啡因（1,3,7 - 三甲基黄嘌呤）进行电化学降解。通过在相对于Ag/AgCl为 -1.0至 +1.0 V的电位范围内进行循环伏安法技术测试电化学降解，这证实了所选咖啡因的电活性。探究了处理工艺变量，如初始pH值、电流密度、电解质浓度和电解时间对咖啡因降解的影响。在电解的各个阶段，分析了化学需氧量（COD）、总有机碳（TOC）等参数。在中性pH值7、电流密度为5.1 mA/cm、电解质（NaSO）浓度为0.1 M以及电解时间为240分钟的条件下，COD和TOC的最大去除效率分别达到85%和77%。从本研究可以得出结论，电化学处理工艺可以有效降低水介质中咖啡因的COD和TOC。通过紫外光谱、红外光谱和高效液相色谱分析证实了咖啡因的降解。
