[Ultrasonic Composite Iron-carbon Activated Persulfate for Treating Organic Wastewater]

A coupling system of ultrasonic composite iron-carbon activated persulfate (US/PS/Fe-C) was built to treat a triphenylmethane derivative, crystal violet (CV). The results revealed that US/PS/Fe-C ternary system had a good coupling effect. The structure and surface morphology of commercial Fe-C and self-made Fe-C catalysts were analyzed using an X-ray diffractometer (XRD) and scanning electron microscope (SEM), respectively. Finally, commercial Fe-C was used to study the effects of different factors on the CV of US/PS/Fe-C ternary coupling degradation, and the optimum conditions were as follows:PDS concentration 2 mmol·L^-1, iron-carbon catalyst 1 g·L^-1, pH without adjustment, and the removal rate of 15 mg·L^-1 CV reached 90% after 30 min. To explore the effects of anions and cations on the system, it was observed that Mg²⁺ and NO₃^- had almost no effect on the treatment of the system, and Mn²⁺, Cl^-, and CO₃^2- had a certain effect on the treatment of the system, whereas Fe²⁺ could promote the reaction at low concentration and inhibit the reaction at high concentration. By adding different quenchants, it was concluded that there were four types of active substances:¹O₂, SO₄^-·,·O₂^-, and·OH.