کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6465514 | 1422952 | 2017 | 9 صفحه PDF | دانلود رایگان |
- Complete, quick decay of tetracaine in 0.050Â MÂ Na2SO4 by EO-H2O2 with BDD anode.
- Tetracaine decay in simulated and real wastewater: IrO2-based < Pt â¼Â BDD < RuO2-based.
- Much larger mineralization (>50%) of tetracaine using BDD, regardless of the matrix.
- Fate of nitrogen atoms: NO3â, soluble N-derivatives and volatile compounds.
- Five aromatic by-products, including a dichloroaromatic: formation of chloroderivatives.
The degradation of 150Â mL of 0.561Â mM tetracaine hydrochloride at pH 3.0 by electrochemical oxidation with electrogenerated H2O2 (EO-H2O2) has been studied at a low current density of 33.3Â mAÂ cmâ2 in three different matrices: 0.050Â MÂ Na2SO4, real urban wastewater and a simulated matrix mimicking its electrolyte composition. Comparative trials were performed in an undivided cell with a 3Â cm2 boron-doped diamond (BDD), Pt, IrO2-based or RuO2-based anode and a 3Â cm2 air-diffusion cathode that allowed continuous H2O2 electrogeneration. In 0.050Â MÂ Na2SO4, much faster and overall removal of tetracaine occurred using BDD because of the large oxidation ability of BDD(OH) formed from anodic water oxidation. In either simulated matrix or real wastewater, the RuO2-based anode yielded the quickest tetracaine decay due to a large production of active chlorine from anodic oxidation of Clâ. For the mineralization of the organic matter content, the BDD/air-diffusion cell was the best choice in all aqueous matrices, always reaching more than 50% of total organic carbon abatement after 360Â min of electrolysis, as expected if BDD(OH) mineralizes more easily the chloroderivatives formed from tetracaine oxidation in the presence of active chlorine. The initial N of tetracaine was partly transformed into NO3â, although the total nitrogen of all solutions always decayed by the release of volatile by-products. In the Clâ-containing matrices, significant amounts of ClO3â and ClO4â were obtained using BDD, whereas active chlorine was much largely produced using the RuO2-based anode. Five aromatic by-products, one of them being chlorinated, along with low concentrations of oxalic acid were identified. The change in toxicity during EO-H2O2 with BDD in the sulfate and simulated matrices was also assessed.
Journal: Chemical Engineering Journal - Volume 326, 15 October 2017, Pages 811-819