Exothermic laws applicable to the degradation of o-phenylenediamine in wastewater via a Fe3+/H2O2 homogeneous quasi-Fenton system

摘要

We studied the exothermic laws of Fe ~(3+) /H _(2) O _(2) homogeneous quasi-Fenton degradation of o -phenylenediamine in waste water, and analyzed the effects of [H _(2) O _(2) ] and [Fe ~(3+) ], initial reaction temperature, and other factors on the solution temperature elevation (Δ t ), temperature elevation duration ( T ), and chemical oxygen demand degradation rate ( η ) during the degradation of the target pollutant. Our study found that [H _(2) O _(2) ] is a major factor affecting Δ t , while [Fe ~(3+) ] and t _(0) are the main factors influencing the exothermic reaction rate. For the conditions wherein [H _(2) O _(2) ] is 0.2 mol L ~(?1) , [Fe ~(3+) ] is 10 mmol L ~(?1) , pH = 7.8, initial reaction temperature is 30 °C, and reaction duration is 30 min, Δ t of 200 mL of 0.04 mol L ~(?1) o -phenylenediamine is 7.2 °C and η is 93.45%. The exothermic reaction between the free radicals (·OH and ) and o -phenylenediamine and the exothermic reaction due to auto-consumption of free radicals are the main reasons for the increased temperature of the solution.