Heterogeneous Metal-Activated Persulfate and Electrochemically Activated Persulfate: A Review

Abstract

The problem of organic pollution in wastewater is an important challenge due to its negative impact on the aquatic environment and human health. This review provides an outline of the research status for a sulfate-based advanced oxidation process in the removal of organic pollutants from water. The progress for metal catalyst activation and electrochemical activation is summarized including the use of catalyst-activated peroxymonosulfate (PMS) and peroxydisulfate (PDS) to generate hydroxyl radicals and sulfate radicals to degrade pollutants in water. This review covers mainly single metal (e.g., cobalt, copper, iron and manganese) and mixed metal catalyst activation as well as electrochemical activation in recent years. The leaching of metal ions in transition metal catalysts, the application of mixed metals, and the combination with the electrochemical process are summarized. The research and development process of the electrochemical activation process for the degradation of the main pollutants is also described in detail.

Enhanced Heterogeneous Peroxymonosulfate Activation by MOF-Derived Magnetic Carbonaceous Nanocomposite for Phenol Degradation

“…− hydrolysis produced H 2 O 2 (Equation ( 5)). Next, HO 2 • − was produced by the H 2 O 2 and •OH through Equation (6). Subsequently, the HO 2 • − decomposed to produce O 2 • − (Equation ( 7)).…”

“…In particular, transition-metal-based catalysts are widely used as PMS activators due to their low toxicity, high abundance, and high catalytic activity [5]. Transition-metal oxides, such as Cu x O y , Mn x O y etc., have been proven to effectively activate peroxymonosulfate (PMS) [6]. For example, the Mn 3 O 4 /CuBi 2 O 4 composite material designed by Zhang et al [7], used for the catalytic activation of PMS, exhibits high phenol (almost 100%) and TOC (74.3%) degradation rates within 10 min.…”

N-Doped Co–Mn/C Dual Metal Oxide as an Activator of Peroxymonosulfate Considering Radical and Nonradical Pathways

“…SO 4 •– are typically derived from peroxymonosulfate (PMS) and peroxydisulfate (PDS) with PMS activating more readily due to its asymmetric structure and longer O–O bond compared to PDS. , Various PMS activation methods have been demonstrated, including ultrasonic, thermal, alkali, UV radiation, transition metals, and carbon materials activation. − However, external energy activation encounters practical limitations due to the extra energy input required, which increases water treatment costs. Co 2+ has shown superior PMS activation efficiency in homogeneous reactions, but the performance of transition metal ions in PMS activation is affected by water system pH, and their homogeneous catalytic use poses recovery challenges, potentially leading to secondary water pollution. , Heterogeneous catalysts, such as Co 3 O 4 , are more suitable for large-scale wastewater treatment, evidenced by their effective activation of PMS for 2,4-dichlorophenol degradation and reduced metal ion concentration in effluent .…”

Heterogeneous Activation of Persulfate by Nickel Oxide/Strontium Carbonate Composite for Sulfamethoxazole Degradation in Water

“…Persulfate can be activated through energy input (thermal, radiation, sonochemical/electrochemical), transition metal ions (iron, cobalt, copper, silver), alkali [5], and heterogeneous activators [6]. In addition, today sonochemical activation has sparked increasing interest as an alternative activation method.…”

“…Such materials are considered promising persulfate activators as they provide a high surface area, facilitating the interaction between persulfate and target pollutants [14]; (ii) Catalytic materials such as metal oxides [15], metal phosphides [16], metal-organic frameworks [17] or monolith catalysts with 3D hierarchical structures like δ-MnO 2 immobilized on 3D nickel foam or 3D α-Co(OH) 2 nanosheets developed on robust nickel foam (NF) [18,19]. These catalysts can enhance sulfate radicals production through redox reactions with persulfate, accelerating the oxidation of contaminants [6].…”