Thermodynamic diagnostics of the depolarization overpotential and electron temperatures of contact surfaces in aerated refinery wastewater

Abstract

A B S T R A C TThe energy balance model is applied to aeration regimes at 1 and 2 m high water columns at the same membrane air distributor, with aim to carry out the diagnostics of depolarization potential and electron temperatures of contact surfaces in aerated refinery waste water, without and with added 5 and 10 mg/l waste motor oil. Diagnostics is carried out of water induced vertical flow velocity, hydrogen and oxygen reversible depolarization overpotentials, electron temperatures, and relative electric permittivity of water adsorption and condensation active centers. The activation energies are determined on the basis of Arrhenius dependence between the oxygen transport rate constants and the phase temperature and of oxygen electrons titrations rate constants and electron temperatures. The linear functional dependence of oxygen solubility degree on hydrogen equilibrium potential is obtained with strong correlation coefficient (R 2 = 0.9745), after the balance is achieved of the sum of chemisorbed oxygen energy in stationary and equilibrium states with sum of evolved hydrogen energy in equilibrium and stationary energy states. It was found that thermodynamic history of the first exothermic isobaric or isochoric hydrogen evolution step is an important criterion in choosing an optimized regime.