PMC:4632479 / 26620-28540
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{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4632479","sourcedb":"PMC","sourceid":"4632479","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4632479","text":"The effect of temperature on the degradation of tetracycline\nTo investigate the effect of temperature on the TC degradation rate, experiments were done with various temperature varying from 25 to 65 °C. With increasing temperature from 25 to 65 °C, the degradation rate constant increased from 0.0229 to 0.1042 min −1. Complete TC degradation occurs after 40, 60 and 75 min of reaction at 65, 55 and 45 °C respectively. The activation of S2O82− can be done under heat to form SO4-• radical as following Eq. (15). Therefore, complete removal of TC by high temperature could be as a result of thermally activated S2O82− oxidation. Moreover, the increase of temperature significantly enhanced the cavitation activity and chemical effects, resulting in greater degradation rate of TC by US/S2O82− process [22, 60].15 S2O8−2+→Termal−activation2SO4−•30°C\u003cT\u003c99°C\nTo investigate the effect of ultrasound on the process kinetics, significant parameters such as activation energy (Ea) play a remarkable role. The effect of temperature on the rate of the reaction and rate constant (k) is obtained by Arrhenius equation according with Eq. (16) [66].16 LnK=Aexp−EaRT\nArrhenius plot can be used to calculate the Activation Energy at various temperatures by graphing ln k (rate constant) versus 1/T (kelvin). The graph between ln k and 1/T is a straight line with an intercept of ln A and the slop of the graph is equal to –Ea/R, where R is a constant equal to 8.314 J/mol-K. According with Arrhenius plot (Fig. 8), the activation energy values of 32.01 (kJ/mol) obtained for degradation of TC by S2O82−/US process. It means that for a successful reaction, the colliding molecules must have a total kinetic energy of 32.01 kJ/mol. The low activation energy indicates that the degradation of TC by S2O82−/US process is thermodynamically feasible.\nFig 7 Contour and 3-D plots showing Interactive effect of pH and TC concentration (mg/L)","divisions":[{"label":"title","span":{"begin":0,"end":60}},{"label":"p","span":{"begin":61,"end":855}},{"label":"label","span":{"begin":810,"end":812}},{"label":"p","span":{"begin":856,"end":1154}},{"label":"label","span":{"begin":1138,"end":1140}},{"label":"label","span":{"begin":1832,"end":1837}}],"tracks":[{"project":"TEST0","denotations":[{"id":"26539297-173-179-1452596","span":{"begin":802,"end":804},"obj":"[\"19285704\"]"},{"id":"26539297-135-141-1452597","span":{"begin":1134,"end":1136},"obj":"[\"18617218\"]"}],"attributes":[{"subj":"26539297-173-179-1452596","pred":"source","obj":"TEST0"},{"subj":"26539297-135-141-1452597","pred":"source","obj":"TEST0"}]},{"project":"2_test","denotations":[{"id":"26539297-19285704-59009435","span":{"begin":802,"end":804},"obj":"19285704"},{"id":"26539297-18617218-59009436","span":{"begin":1134,"end":1136},"obj":"18617218"}],"attributes":[{"subj":"26539297-19285704-59009435","pred":"source","obj":"2_test"},{"subj":"26539297-18617218-59009436","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"TEST0","color":"#ec93d2","default":true},{"id":"2_test","color":"#93ecec"}]}]}}