Voltammetric monitoring photodegradation of EDTA based on carbon nanotubes-modified electrode

Determination of ethylenediaminetetraacetic acid base on the reversion of fluorescence quenching of 2-pyridinecarbaldehyde-p-phenyldihydrazone by ferric iron

A fast and sensitive fluorometric method for determination of an emerging pollutant, ethylenediaminetetraacetic acid (EDTA), was proposed based on the reversion of fluorescence quenching of 2-pyridinecarbaldehyde-p-phenyldihydrazone by ferric iron. It was found that Fe(3+) could selectively quench the fluorescence of 2PC-PPH, while EDTA could recover it due to its strong coordination ability with Fe(3+). Based on this, we established an "Off and On" fluorescence method for determination of EDTA. Under the optimum conditions, the linear range and detection limit (3S/N) for EDTA determination were 2.0 × 10(-6)~1.4 × 10(-5) mol L(-1) and 1.5 × 10(-7) mol L(-1), respectively. The relative standard deviation for the determination of 7.0 × 10(-6)mol L(-1) EDTA was 3.7% (n=11). The method was successfully applied to determination of EDTA in tap water, lake water and investigating degradation of EDTA by TiO2/UV process.

Magnetic loading of TiO2/SiO2/Fe3O4 nanoparticles on electrode surface for photoelectrocatalytic degradation of diclofenac

A novel magnetic nanomaterials-loaded electrode developed for photoelectrocatalytic (PEC) treatment of pollutants was described. Prior to electrode fabrication, magnetic TiO(2)/SiO(2)/Fe(3)O(4) (TSF) nanoparticles were synthesized and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and FT-IR measurements. The nanoparticles were dispersed in ethanol and then immobilized on a graphite electrode surface with aid of magnet to obtain a TSF-loaded electrode with high photoelectrochemical activity. The performance of the TSF-loaded electrode was tested by comparing the PEC degradation of methylene blue in the presence and absence of magnet. The magnetically attached TSF electrode showed higher PEC degradation efficiency with desirable stability. Such a TSF-loaded electrode was applied to PEC degradation of diclofenac. After 45 min PEC treatment, 95.3% of diclofenac was degraded on the magnetically attached TSF electrode.