Research on the degradation mechanism of dimethyl phthalate in drinking water by strong ionization discharge

Abstract

The degradation mechanism of dimethyl phthalate (DMP) in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DMP in drinking water was up to 93% in 60 min. A series of analytical techniques including high-performance liquid chromatography, liquid chromatography mass spectrometry, total organic carbon analyzer and ultraviolet-visible spectroscopy were used in the study. It was found that a high concentration of ozone (O 3) produced by dielectric barrier discharge reactor was up to 74.4 mg l −1 within 60 min. Tert-butanol, isopropyl alcohol, carbonate ions CO 3 2-() and bicarbonate ions HCO 3-() was added to the sample solution to indirectly prove the presence and effect of hydroxyl radicals (•OH). These analytical findings indicate that mono-methyl phthalate, phthalic acid (PA) and methyl ester PA were detected as the major intermediates in the process of DMP degradation. Finally, DMP and all products were mineralized into carbon dioxide (CO 2) and water (H 2 O) ultimately. Based on these analysis results, the degradation pathway of DMP by strong ionization discharge technology were proposed.

A Study of the Performance of Dielectric Barrier Discharge under Different Conditions for Nitrobenzene Degradation

“…The use of DBD technology for wastewater degradation [15][16][17] is a novel approach towards wastewater treatment. DBD plasma systems produce active species such as O 3 , • OH, oxygen atom radicals and H 2 O 2 that allow the organic pollutants to decompose [16,[18][19][20][21][22][23]. These active species act as powerful oxidizing agents that can prompt chain reactions in pollutant molecules and are expected to degrade wastewater pollutants.…”

“…When oxygen is provided, high voltage power is applied to the DBD reactor, O 2 molecules get excited and produce a strong discharge in the displacement between the two dielectric layers. As a result, both the physical and chemical reactions occur simultaneously, producing a huge quantity of active species with a high activity [22,23,26]. Hydroxyl radicals ( • OH) are produced, when the active species like O 3 , • O, O 2 + and O 2 − enter the water.…”

The Applications of Plasma Gas Injection for Pollutants Treatment

“…In addition to inactivating algae, this novel plasma gas injection is successfully used to remove pathogenic bacteria [72], antibiotics [73], and organic pollutants [74], [75] in drinking water, and the details are described in Table II. Furthermore, to achieve its broad use in drinking water treatment, it is necessary to investigate the treatment impact of plasma gas injection on composite pollutants in the real water sources.…”