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

Carbamazepine (CBZ) antibiotic organic contamination wastewater poses a huge threat to environmental safety. An advanced oxidation technology (Fe/PDS/US) of using ultrasound (US) enhanced zero-valent iron/potassium persulfate (Fe/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 dosage on the removal of CBZ. In addition, we also investigated into the effect of background ions (PO, HCO, Cl and HA) on Fe/PDS/US and analyzed the related results. The mechanism of CBZ removal in Fe/PDS/US were explored by analyzing CBZ removal efficiency and reaction rates, the ion concentration of SO, SO, Fe and Fe, pH and the active radicals. The result indicates that US can improve the efficiency of activated PDS and expand the pH range of Fe/PDS. It has prominent performance in catalytically degrading CBZ when the pH is 10.0. SO, OH and O all coexist in the Fe/PDS/US and make contribution to CBZ removal, whereas the SO 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 Fe with a continuous and stable way, and better activating SO to generate sufficient SO 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 biodegradation of products. The Fe/PDS/US is of great potential application value in removal of organic pollution and environmental purification.