An integrated photocatalytic microfluidic platform enabling total phosphorus digestion. (15th January 2015)

• Record Type: Journal Article
• Authors: Tong, Jianhua; Dong, Tian; Bian, Chao; Wang, Minrui; Wang, Fangfang; Bai, Yin; Xia, Shanhong
• Is Part Of: Journal of micromechanics and microengineering. Volume 25:Number 2(2015:Feb.)
• Publication Date: 2015-01-15
• Subjects: microfluidics -- total phosphorus -- digestion; Microelectromechanical systems -- Periodicals; Micromechanics -- Periodicals; 621.38105
• DOI: 10.1088/0960-1317/25/2/025006
• Languages: English
• ISSNs: 0960-1317

Abstract

Abstract: This paper presents an integrated thermally assisted photocatalytic microfluidic chip and its application to the digestion of total phosphorus (TP) in freshwater. A micro heater, a micro temperature sensor, thermal-isolation channels and a polymethylsiloxane (PDMS) reaction chamber were fabricated on the microfluidic chip. Nano-TiO2 film sputtered on the surface of silicon in the reaction area was used as the photocatalyst, and a micro ultraviolet A-ray-light-emitting diode (UVA-LED) array fabricated by MEMS technology were attached to the top of reaction chamber for TP degradation. In this study, sodium tripolyphosphate (Na5 P3 O10 ) and sodium glycerophosphate (C3 H7 Na2 O6 P) were chosen as the typical components of TP, and these water samples were digested under UVA light irradiation and heating at the same time. Compared with the conventional high-temperature TP digestion which works at 120 °C for 30 min, the thermally assisted UVA digestion method could work at relatively low temperature, and the power consumption is decreased to less than 2 W. Since this digestion method could work without an oxidizing reagent, it is compatible with the electrochemical detection process, which makes it possible to achieve a fully functional detection chip by integrating the digestion unit and electrochemical microelectrode, to realize the on-chip detection of TP, and other water quality parameters such as total nitrogen and chemical oxygen demand.