Hydrogen accelerated regeneration of FeII in Fenton reaction enhanced by Pd/MOF-808(Zr)

Abstract

The promotion of Fenton process in organic wastewater treatment has been hindered by the disposal of large amounts of iron sludge derived from the excess addition of ferrous salt. The operation of the Fenton reaction could be maintained using trace level Fe II through the effective acceleration reaction of active hydrogen. However, the H 2 which is the precursor of active hydrogen is insoluble in water. Herein, the composite catalyst Pd/MOF-808(Zr) was introduced into the H 2 -Fenton system to enhance the adsorption and activation of this reducing gas. In this novel improved Fenton system called MHACF-MOF-808(Zr), the hydroxyl radical would be unceasingly produced based on the unceasingly recycling of FeII/FeIII at normal temperature and pressure. 15 mg L −1 sulfamethazine could be thoroughly degraded during 2 h reaction process in the initial condition of 60 mL min −1 H 2 , 20 μmol L −1 Fe II , pH 3, 20 mmol L −1 H 2 O 2 and 2 g L −1 Pd/MOF-808(Zr). And so did 10 mg L −1 2,4-Dichlorophenol. The activity and stability of Pd/MOF-808(Zr) could be maintained after at least 6 consecutive reaction cycles. It provides new insight for improving the inherent shortcoming of the Fenton reaction which will generate large amounts of iron sludge. • The novel MHACF-MOF-808(Zr) system was used to degrade 2,4-Dichlorophenol and sulfamethazine in aqueous solution. • It exhibited higher removal efficiency than that of classic Fenton reaction system. • The introduction of H 2 and Pd/MOF-808(Zr) accelerated the reduction of Fe Ⅲ back to Fe Ⅱ in Fenton reaction. • Only trace level Fe Ⅱ was needed.