Metal Foam-based Fenton-like Process By Aeration

Fenton process is one of the AOPS,and hydroxyl radical produced by Fenton is a strong agent,which can oxide pollutants rapidly and efficiently.Thus,Fenton process has been widely applied in wastewater treatment.However,a large amount of ironsludge produced by traditional Fenton processes may restrict its wider application.Heterogeneous Fenton system and E-Fenton system which are improved traditional Fenton systems are more efficient and environmentally friendly.Nevertheless,the addition of H₂O₂ is an inevitable part for heterogeneous Fenton system.Although E-Fenton could generate H₂O₂ in situ,the supply power unit is indispensable for all E-Fenton processes.The limitations mentioned above not only complicate the process,but also increase the cost.Therefore,a more convenient and efficient Fenton-like system is worth researching.In the process,only metal foam,air aeration and iron ion were required to achieve the efficient removal of pollutants.Metal foam could activate oxgen to produce superoxide radical,then the generation of H₂O₂,in which way the removal of pollutants could be achieved.The form of metals had great influence on the efficiency of treating with pollutants.Moreover,metal foams showed superior efficiency to metal plates,which was due to the high specific surface area of metal foams.The experimental results suggested that only metal foam,air aeration and Fe²⁺were required to achieve the efficient removal of pollutants.Ni foam could activate O₂ to produce superoxide radical,which could then react with H⁺to generate H₂O₂.The other role Ni foam played was to accelerate the cycle of Fe³⁺/Fe²⁺,which could promote the degradation of pollutant.The results showed the optimum conditions for this Fenton-like process weredetermined to be pH 3and Fe²⁺concentration of 0.25 mmol·L^-1,under which 94%of MB can be removed.The results claimed that Ni foam-based Fenton-like process was ageneral approach to be applied on the degradation of other pollutants.Three other metal foams were applied on the proposed Fenton-like process.The experimental results revealed that Al foam and Cu foam could be applied on the Fenton-like system.However,Ti foam had little influence to initiate the Fenton-like reaction.