Mechanism Of Peroxymonosulfate Activation By Transition Metal Compounds For Organic Pollutants Degradation

Sulfate radicals(SO₄^·-)based advanced oxidation technologies have received increasing attention in recent years.Peroxymonosulfate?PMS?is a good sulfate radical precursor.Transition metals compounds are commonly used as activators of persulfate and peroxymonosulfate.However,metal ion release poses a secondary risk during the homogenous activation of PMS for environmental remediation.Heterogeneous activators were developed to put up with these drawbacks and have received more attention in recent study.Such transition metal oxides are also difficult to apply on a large scale because of the complex synthesis steps and high cost.Further efforts are needed to develop a high-efficiency,environmentally-friendly and low-cost peroxymonosulfate activator.In this paper,2,4,4'-Trichlorobiphenyl?PCB28?and Diethyl phthalate?DEP?selected as model pollutants.A series of complexes of transition metals and biochar were synthesized to activate peroxymonosulfate to degrade PCB28.First use of copper sulfide for the activation of peroxymonosulfate?PMS?for pollutant degradation.The underlying mechanism was studied.The main research results obtained are as follows:?1?Synthesized some complex of multiple metal oxides?Fe,Ni,Cu,Zn?and biochar,these materials are used to activate various oxidants?H₂O₂,Na₂S₂O₈,PMS?for PCB28degradation.?2?The degradation of diethyl phthalate by the CuS/PMS system was studied.Effects of CuS loading,PMS concentration,pH and anions on DEP degradation were studied.?3?The mechanism of PMS activation by CuS was studied.Electron paramagnetic resonance,free radical quenching,X-ray photoelectron spectroscopy,X-ray diffraction analyses suggested that?Cu???/?Cu??? cycling on the surface of CuS provided the main pathway to activate PMS to produce highly oxidative species.