The graceful art, significant function and wide application behavior of ultrasound research and understanding in carbamazepine (CBZ) enhanced removal and degradation by Fe0/PDS/US

Carbamazepine (CBZ) antibiotic organic contamination wastewater poses a huge threat to environmental safety. An advanced oxidation technology (Fe-0/PDS/US) of using ultrasound (US) enhanced zero-valent iron/potassium persulfate (Fe-0/PDS) can remove CBZ effectively. The optimal reaction conditions were determined by exploring the effect of single-factor experimental conditions such as ultrasonic power, ultrasonic frequency, CBZ concentration, solution pH, PDS dosage, and Fe-0 dosage on the removal of CBZ. In addition, we also investigated into the effect of background ions (PO43-, HCO3-, Cl- and HA) on Fe-0/PDS/US and analyzed the related results. The mechanism of CBZ removal in Fe-0/PDS/US were explored by analyzing CBZ removal efficiency and reaction rates, the ion concentration of S2O82-, SO42-, Fe2+ and Fe3+, pH and the active radicals. The result indicates that US can improve the efficiency of activated PDS and expand the pH range of Fe-0/PDS. It has prominent performance in catalytically degrading CBZ when the pH is 10.0. SO4 center dot-, (OH)-O-center dot and O-2(center dot-) all coexist in the Fe-0/PDS/US and make contribution to CBZ removal, whereas the SO4 center dot- plays a key role. US can greatly promotes the degradation of target pollutant CBZ by speeding up the dissolution of the outer portion of iron powder, producing sufficient amount of Fe2+ with a continuous and stable way, and better activating S2O82- to generate sufficient SO4 center dot- radicals. The degradation of CBZ may embrace three reaction processes, in which organic intermediate products with low molecular weight and biological toxicity is produced, boosting further mineralization and

Automated summary

The advanced oxidation technology of using ultrasound enhanced zero-valent iron/potassium persulfate can effectively remove carbamazepine antibiotic organic contamination wastewater, with ultrasound playing a key role in improving the efficiency of the reaction and expanding the pH range for CBZ degradation. The mechanism involves the generation of active radicals such as SO4·−, (OH)·, and O2(·−) which contribute to the removal of CBZ, with SO4·− playing a prominent role. The degradation process is promoted by the dissolution of iron powder, production of Fe2+ ions, and activation of S2O82- to produce sufficient SO4·− radicals, leading to the efficient degradation of CBZ.