Repozytorium publikacji - Politechnika Gdańska

Hydrodynamic cavitation (HC) was employed to activate sodium percarbonate (SPC) and ozone (O3) to degrade recalcitrant 1,4-dioxane. The degradation efficiency > 99 % with a rate constant of 4.04 × 10−2 min−1 was achieved in 120 min under the optimal conditions of cavitation number (Cv) 0.27, pH 5, molar ratio of oxidant to pollutant (rox) 8, ozone dose of 0.86 g h−1 under 25 ± 2 °C with initial concentration of 1,4-dioxane 100 ppm. The application of HC with SPC/O3 increased the degradation efficiency by 43.32 % in 120 min, confirming a synergistic effect between the coupled processes. In addition, the degradation efficiency of 1,4-dioxane in HC/SPC/O3 was superior as compared to HC/H2O2/O3, suggesting that the presence of SPC has a significant role in degradation of 1,4-dioxane. Radical quenching experiment revealed highest contribution of hydroxyl (HOradical dot) radicals in the degradation of 1,4-dioxane among carbonate (CO3radical dot−) and superoxide (O2radical dot−) radicals. The presence of co-existing anions resulted in an inhibitory effect in the following order: SO42− > NO3− > Cl−. Based on GC–MS analysis, ethylene glycol diformate (EGDF) was detected as the main degradation product of 1,4-dioxane. The observed intermediate supports the radical route of 1,4-dioxane oxidation, which involves H-abstraction, ΔC-C splitting at the α-C position, subsequent dimerization, fragmentation and mineralization. Electric energy per order (EEO) for best process was 102.65 kWh·m−3·order−1. Total cost of treatment was estimated as approx. 12 USD/m3. These findings confirmed the SPC as an efficient, environmentally-friendly alternative to H2O2 and broadened the scope of HC-based AOPs for water and wastewater treatment.

Autorzy

• Kirill Fedorov link otwiera się w nowej karcie ,
• Manoj P Rayaroth,
• Noor Shah,
• dr hab. inż. Grzegorz Boczkaj link otwiera się w nowej karcie