The electrochemical oxidation of organic pollutants is a promising process for substances which are recalcitrant to biological degradation. The anodic oxidation of coumaric acid, which is a biorefractory organic pollutant of olive oil manufacturing waste waters, was evaluated on a Pt–Ti electrode. The operating test conditions were compatible with direct discharge of the after-treatment effluent in natural water basins or rivers as regards the electrolyte salt content (Na2SO4=0.02 N). The effect of the applied current density, pH, temperature, initial coumaric acid concentration and of the type of DC feeder (a galvanostat or a simple current rectifier) over the oxidation rate was assessed through a series of batch runs performed in a pilot plant apparatus. Beyond direct oxidation at the Pt-electrode surface, bulk oxidation with hydrogen peroxide, generated through a persulfate-formation/hydrolysis route, was found to be a crucial step in coumaric acid degradation to more biodegradable non-aromatic products. Small quantities of Fe ions were helpful in accelerating the oxidation process. An analysis of the rather complex reaction schemes governing the process is proposed.
|Titolo:||Electrochemical oxidation of organic pollutants at low electrolyte concentrations|
|Data di pubblicazione:||2000|
|Digital Object Identifier (DOI):||10.1016/S0013-4686(00)00594-6|
|Appare nelle tipologie:||1.1 Articolo in rivista|