Degradation Of Bisphenol-A And Carbamazepine In Aqueous Solution By Fenton/Persulfate System

With the rapid development of economic and the improvement of industrialization,the pollution of water resource is becoming more and more serious in China.Meanwhile,more kinds and higher content of organic pollutants have been detected in water sourse.These organic pollutants existing in the environment have seriously threatened human health,some of which have become the focus of environmental science treatment at present,like endocrine disruptors,drugs and personal care products.Persistent and nonbiodegradable organic compounds bisphenol-A and carbamazepine were investigated using Fenton-activated persulfate and the mechanism of their degradation also was studied.（1）Through degrading bisphenol-A（BPA）by Fenton/persulfate systems,the affection of the ferrous ion dosage,the H₂O₂ dosage,the persulfate dosage,initial pH values,and substrate concentration were discussed,and the degradation mechanism was conjectured.The results showed that:（1）The Fenton/persulfate systems perform well on degrading BPA,the highest degradation rate reaching 100%.（2）Increasing the concentration of Fe²⁺dosage can improve the degradation rate of BPA,the optimum condition is which BPA can be completely removed in 30min.（3）Increasing the concentration of H₂O₂ can improve the degradation efficiency of BPA.However,the increase of persulfate dosage first increased and then decreased in the degradation rate of BPA.When the molar ratio of BPA/S₂O₈^2-is above 1/2.5,the increase of persulfate dosage will inhibit the degradation of BPA.The reason is that excessive persulfate will scavenge HO·and SO₄^-·leading to restrain the BPA removal.（4）With the increase of initial pH value,the degradation rate of BPA decreased,but the Fenton/persulfate systems show great performance in BPA degradation at a wide range of pH even at near-neutral and alkaline conditions.Under alkaline condition,95%BPA are removed in50min.（5）The degradation pathway has been deduced by LC-MS analysis.The addition reaction,hydrogen extraction,beta-scission and resonance reaction are the main reaction in degradation process,while the intermediates are degraded into other small molecules and may be further mineralized into CO₂ and H₂O.（2）Through degrading carbamazepine（CBZ）by Fenton/persulfate systems,the affection of the ferrous ion dosage,the H₂O₂ dosage,the persulfate dosage,initial pH values,and substrate concentration were discussed.The results showed that:（1）Increasing the concentration of Fe²⁺can fortify the removal rate of CBZ,and the best condition is 83.8%degradation efficiency of CBZ in 30min.（2）The improvement of H₂O₂ dosage lead to an enhancement in CBZ removal rate,and the maximum CBZ removal was 62%in 30min.The further increase of H₂O₂ dosages,however do not increase evidently in CBZ removal when H₂O₂ dosages reached 0.75mmol/L.（3）CBZ removal rate first increases and then decreases with augmenting persulfate dosage,excessive persulfate dosage resulting in a decline in CBZ degradation.（4）CBZ decay rate dropped rapidly with the increase of the initial pH level.（5）Increasing initial CBZ concentration lead to reduce the degradation rate of CBZ,but the total removal amount of CBZ increased at the end of the reaction.Fenton/PS systems perform well on degrading bisphenol-A and carbamazepine,and have a good potential on degrading refractory organic pollutants.