Heterogeneous Advanced Oxidation Processes: Current Approaches for Wastewater Treatment

Abstract

Nowadays, water pollution is one of the most dangerous environmental problems in the world. The presence of the so-called emerging pollutants in the different water bodies, impossible to eliminate through conventional biological and physical treatments used in wastewater treatment plants due to their persistent and recalcitrant nature, means that pollution continues growing throughout the world. The presence of these emerging pollutants involves serious risks to human and animal health for aquatic and terrestrial organisms. Therefore, in recent years, advanced oxidation processes (AOPs) have been postulated as a viable, innovative and efficient technology for the elimination of these types of compounds from water bodies. The oxidation/reduction reactions triggered in most of these processes require a suitable catalyst. The most recent research focuses on the use and development of different types of heterogeneous catalysts, which are capable of overcoming some of the operational limitations of homogeneous processes such as the generation of metallic sludge, difficult separation of treated water and narrow working pH. This review details the current advances in the field of heterogeneous AOPs, Fenton processes and photocatalysts for the removal of different types of emerging pollutants.

Treatment Trends and Combined Methods in Removing Pharmaceuticals and Personal Care Products from Wastewater—A Review

“…Activated sludge treatment is typically used in conventional WWTPs to remove PPCPs. Their removal using this process depends on the size and layout of the sludge bioreactor and treatment factors such as pH and retention times (both sludge and hydraulic) and is specific to the various types of PPCP compounds [ 37 , 38 ]. Table S1 demonstrates the extent to which a range of PPCPs is removed by WWTPs.…”

“…Many reviews have discussed a variety of processes for removing PPCPs from the environment, especially water. These processes include adsorption [ 3 , 29 , 30 , 31 ], ozone-based processes [ 32 , 33 ], ozonation [ 16 , 34 ], membrane filtration [ 35 , 36 ], Fenton oxidation [ 16 , 37 ], UV oxidation [ 16 ] and biological processes [ 16 , 38 ]. However, these processes were not integrated into most studies to take advantage of the different mechanisms specific to each process and to be synergistic enough in the removal of the PPCPs.…”

Catalytic Ozonation of Ibuprofen in Aqueous Media over Polyaniline–Derived Nitrogen Containing Carbon Nanostructures

“…In recent years, carbon-based materials such as graphene, graphitic carbon nitride, mesoporous carbon, activated carbon, nanodiamonds, fullerenes, and carbon nanotubes have been successfully investigated in heterogeneous catalysis, both as supports and as catalysts, thanks to their catalytic activity and facilely-tuned surface chemistry, together with their large surface area, stability, and reusability [13,14,[31][32][33][34][35][36][37]. It is now believed that the introduction of heteroatoms into carbon frameworks (e. g., nitrogen, sulfur, phosphorus, and boron) is an excellent strategy that can significantly improve the catalytic performances of carbon catalysts [32].…”

Amoxicillin Trihydrate Characterization and investigative adsorption using a Brazilian montmorillonite

“…Advanced technologies such as Advanced Oxidative Processes (AOPs) and adsorption by activated carbon has been pointed out as the most efficient processes regarding these pollutants removal [3,[14][15][16][17][18][19][20][21]. However, although efficient, these processes present limitations with their cost, making their large-scale application unfeasible.…”