An overview on combined electrocoagulation-degradation processes for the effective treatment of water and wastewater

Advanced Oxidation Processes Based on Sulfate Radicals for Wastewater Treatment: Research Trends

“…In AOPs, the solution pH is an important parameter, since it influences the action of the oxidants and catalysts, as well as the degradation of pollutants [52]. In the case of SR-AOPs, several studies evaluated the effect of a wide pH range in the applicability of this kind of AOPs [16,38], as PMS and PDS are relatively stable compounds throughout the pH scale. It has been reported that PMS can be hydrolyzed in acidic media, although below a pH of 1 [7].…”

“…There is a vast number of studies in the literature that indicate the advantages of SR-AOPs in comparison to other AOPs, due to better decontamination prospects having been reported compared to those AOPs based exclusively on HO•. Among the benefits, the following can be named: the formation of radicals in a wider pH range of water (from 2 to 8 pH units) [16,33,54], a longer shelf-life of SO 4 • − compared to HO• (20 ns for HO• vs. 30-40 µs for SO 4 • − ) [16,37,48,50], a high selectivity for the removal of pollutants [8,31,33,37,54], a larger redox potential at a circumneutral pH (1.8-2.7 V for HO• vs. 2.5-3.1 V for SO 4 • − ) [8,32,33,48,50,54,63] and the generation of SO 4 • − along with HO• in PMS [54]. Additionally, PDS is an easily available reactant [64].…”

“…Besides pathogens, bacteria and genes resistant to antibiotics [9], the main pollutants include organic compounds such as pharmaceuticals, personal care products, perfluorinated compounds, pesticides, surfactants, flame retardants, dyes and a wide variety of industrial additives and synthetic chemical compounds [5,[10][11][12][13][14]. Among these pollutants, the group of emerging contaminants (ECs) stands out due to their bioaccumulable, persistent and toxic character, along with their carcinogenic and mutagenic potential, posing a risk to human health and the environment [15][16][17][18], and constituting a concern of great interest nowadays [19]. Additionally, several ECs are not yet included in the legislation of many countries, or there is no legal regulation determining the maximum allowable levels of these substances in the environment [20][21][22][23].…”

“…However, even though SR-AOPs have several disadvantages ascribed to them, the coupling of SR-AOPs and conventional processes is recommended for effective WW treatment [16,43]. In fact, from the literature review, there is growing attention on coupling AOPs based on SO 4 • − and bioremediation systems [10,19].…”

Evaluation of electrocoagulation in the post-treatment of anaerobic wastewater of slaughterhouse and packing plant

“…Electrocoagulation is an electrochemical technique used to destabilize the contaminants with electric current. The reactor consists of an electrolytic cell which is formed by sacrificial metal electrodes (normally Fe or Al), being an anode and a cathode, connected to the direct current power supply (Nidheesh et al, 2021).…”