20.500.12556/RUL-116143 Anomalies detected during hydrodynamic cavitation when using salicylic acid dosimetry to measure radical production Cavitation used to be associated with negative outcomes in hydraulic turbomachinery but nowadays it is often used for water cleaning, microorganism’s destruction and degradation of organic compounds. This study investigated the amount of ·OH formed during hydrodynamic cavitation using salicylic acid dosimetry. The radical’s amount was evaluated by quantifying the concentration of 2,3-dihydroxybenzoic acid, catechol and 2,5-dihydroxybenzoic acid. Two concentrations of the dosimeter in tap water were investigated, 50 and 300 mg L$^{−1}$ (pH approx. 2.5). After 90 min of cavitation using a Venturi constriction a sum of the three products was determined at 0.97 µg mL$^{−1}$ and 1.81 µg mL$^{−1}$, respectively. However, during the investigation the anomalies were detected in the cavitation development when higher concentration of salicylic acid was used – cavitation appeared more gentle, with less intense collapses, unrelated to the one in pure water. Detailed observations of cavitation and additional bubble dynamics simulations revealed that the decreased surface tension of the acidified salicylic acid solution is the most influential physical characteristic. Further experiments on nucleation and coalescence showed that high concentration of salicylic acid also leads to longer stability of the bubbles and prevents their coalescence due to short-range repulsive forces (steric hindrance), which results in less violent bubble collapse. We also discuss the importance of an appropriate amount of the dosimeter for correct evaluation of ·OH production in a given cavitation device (50 mg L$^{−1}$ for the present one). This is essential for further cavitation exploitation studies to avoid false interpretation of the gathered results. cavitation nucleation coalescence salicylic acid dosimetry anomalies physical characteristics kavitacija nukleacija koalescenca dozimetrija salicilne kisline anomalije fizikalne lastnosti true false true Angleški jezik Slovenski jezik Članek v reviji 2020-05-18 11:32:07 2020-05-18 11:32:14 2022-08-28 03:47:22 0000-00-00 00:00:00 2020 0 0 11 str. art. 125389 Vol. 396 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532.528(045) 1385-8947 10.1016/j.cej.2020.125389 15039491 2110998 RAZ_Zupanc_Mojca_2020.pdf RAZ_Zupanc_Mojca_2020.pdf 1 82C554ED8F4CD859F4C8E36F004CCD65 74700aa73fcf08b7f92038a63d25b952b9e806b254ea46c63e21940485e565d4 d2f9af30-a1b8-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=129552 https://www.sciencedirect.com/science/article/pii/S1385894720313814 0 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=129550 Fakulteta za strojništvo Fakulteta za farmacijo 0 0 0