Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FO...Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FOT have not been well explored.The current study aims to investigate the formation of chlorinated phenolic byproducts upon ferrate(VI)oxidation processes.The obtained results indicate that chlorides suffering ferrate(VI)attack will be transformed to active chlorine species(ACS),which will subsequently lead to the formation of highly toxic aromatic chlorinated byproducts.The identified byproducts include common chlorinated phenolic derivatives,as well as complex chlorinated oligomer byproducts with ether structures(mainly dimers and trimers).While the formation of common chlorophenols can be ascribed to the electrophilic substitution reactions mediated by ACS,the oligomer byproducts are generated via coupling reactions between chlorinated phenoxy radicals.ECOSAR software predicts that the generated chlorinated oligomer byproducts exhibit high ecotoxicological effects.As a whole,the above findings shed light on the potential risk of FOT in real practice.展开更多
In order to improve the yield and stability of ferrate in solution, dissolved Fe(Ⅵ) prepared with NaOH and KOH respectively was compared in this study. The results showed that KOH is more suitable than NaOH for the p...In order to improve the yield and stability of ferrate in solution, dissolved Fe(Ⅵ) prepared with NaOH and KOH respectively was compared in this study. The results showed that KOH is more suitable than NaOH for the preparation of dissolved Fe(Ⅵ) at temperature over 50 ℃. It is found that the dissolved Fe(Ⅵ) prepared with KOH increases quickly at first, and then slowly with the increasing concentrations of OH-and ClO-, while it increases rapidly at first and then decreases rapidly with the increasing dosage of Fe(NO3)3·9H2O. These results are different from that prepared with NaOH. It can be explained that solid K2FeO4 salts can be formed in KOH solution, and it will lower the Fe(Ⅵ) concentration, counteract the decomposition of Fe(Ⅵ), and improve the yield of Fe(Ⅵ). The maximum ferrate concentration is 0.163 mol/L obtained by 100 g/L Fe(NO3)3·9H2O and 6.16 mol/L KOH at 65 ℃. The stability of Fe(VI) is greatly improved due to the hypochlorite existed in the dissolved ferrate, and only 24% Fe(Ⅵ) has been decomposed after 16 d for 1 mmol/L Fe(Ⅵ) at 25 ℃.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Nos.KYCYXT2023001,and XUEKEN2022034).
文摘Currently,ferrate(VI)oxidation technology(FOT)has been regarded as one of the most promising options for the degradation of emerging organic pollutants.However,the role and transformation of chloride ions(Cl^(−))in FOT have not been well explored.The current study aims to investigate the formation of chlorinated phenolic byproducts upon ferrate(VI)oxidation processes.The obtained results indicate that chlorides suffering ferrate(VI)attack will be transformed to active chlorine species(ACS),which will subsequently lead to the formation of highly toxic aromatic chlorinated byproducts.The identified byproducts include common chlorinated phenolic derivatives,as well as complex chlorinated oligomer byproducts with ether structures(mainly dimers and trimers).While the formation of common chlorophenols can be ascribed to the electrophilic substitution reactions mediated by ACS,the oligomer byproducts are generated via coupling reactions between chlorinated phenoxy radicals.ECOSAR software predicts that the generated chlorinated oligomer byproducts exhibit high ecotoxicological effects.As a whole,the above findings shed light on the potential risk of FOT in real practice.
文摘In order to improve the yield and stability of ferrate in solution, dissolved Fe(Ⅵ) prepared with NaOH and KOH respectively was compared in this study. The results showed that KOH is more suitable than NaOH for the preparation of dissolved Fe(Ⅵ) at temperature over 50 ℃. It is found that the dissolved Fe(Ⅵ) prepared with KOH increases quickly at first, and then slowly with the increasing concentrations of OH-and ClO-, while it increases rapidly at first and then decreases rapidly with the increasing dosage of Fe(NO3)3·9H2O. These results are different from that prepared with NaOH. It can be explained that solid K2FeO4 salts can be formed in KOH solution, and it will lower the Fe(Ⅵ) concentration, counteract the decomposition of Fe(Ⅵ), and improve the yield of Fe(Ⅵ). The maximum ferrate concentration is 0.163 mol/L obtained by 100 g/L Fe(NO3)3·9H2O and 6.16 mol/L KOH at 65 ℃. The stability of Fe(VI) is greatly improved due to the hypochlorite existed in the dissolved ferrate, and only 24% Fe(Ⅵ) has been decomposed after 16 d for 1 mmol/L Fe(Ⅵ) at 25 ℃.
