Effects of Advanced Oxidation Processes on the Decomposition Properties of Organic Compounds with Different Molecular Structures in Water

Abstract

Studies to decompose persistent organic pollutants in wastewater from chemical factories by using Advanced Oxidation Processes (AOPs) have recently been performed. Oxidation reactions involving ozone and •OH radicals and cleavage caused by UV are the main decomposition reactions that occur in AOPs using ozone and UV. The mechanisms through which organic compounds are decomposed in AOPs are complicated and difficult to understand because various decomposition reactions occur simultaneously. The Total Organic Carbon (TOC) removal efficiencies achieved in several different AOPs were evaluated in this study. The TOC removal efficiencies were different for organic compounds with different chemical structures. The TOC was more effectively removed when aromatic compounds were treated using the O3-UV-TiO2 process than when using the other AOPs, and the TOC was removed more effectively by the O3-UV process than by the UV-TiO2 process. However, the TOC was removed more effectively when open-chain compounds were treated using the UV-TiO2 process than using the O3-UV process, and the UV-TiO2 and O3-UV-TiO2 processes resulted in similar TOC removal efficiencies. Therefore, it is necessary to use the O3-UV-TiO2 process to decompose aromatic compounds as quickly as possible. On the other hand, the UV-TiO2 process degraded the open-chain compounds most effectively, and the O3-UV-TiO2 process did not need to decompose open-chain compounds. Moreover, the TOC of aromatic compounds was removed more slowly than that of open-chain compounds. The TOC removal efficiency increased with decreasing the number of carbon atoms in the molecule. The TOC removal efficiencies increased in order of the organic compounds containing methyl groups, aldehyde groups and carboxyl groups. The removal of the TOC when organic compounds were treated using the O3-UV-TiO2 process followed pseudo-zero-order kinetics.

Decomposition of Contaminants of Emerging Concern in Advanced Oxidation Processes

“…Differences in the removal rates of the examined compounds, which were observed in all conducted AOPs, results mainly from the different chemical structures of the decomposed compounds. Suzuki et al [28] reported that aromatic compounds were slower to degrade than the open-chain compounds. Additionally, the number of carbon atoms and the presence of functional groups determine the ability of a compound to decompose [28].…”

“…Suzuki et al [28] reported that aromatic compounds were slower to degrade than the open-chain compounds. Additionally, the number of carbon atoms and the presence of functional groups determine the ability of a compound to decompose [28]. The type of chemical bonds between the atoms of the compound molecule and their energy also determines the emerging decomposition by-products and their future mineralization.…”

Validation of a Process for the Elimination of Naphthenic Acids in Oil Sands Process-affected Water

“…The second category is unreacted polycyclic naphthenic acids which are NAs that contain at least one cyclical structure and did not undergo oxidation in the previous process (Figure 8). Figure 2.12 Oxidation of an Aldehyde into a Carboxylic Acid (Suzuki, et al, 2016) The method for biodegradation of these products will be through heterotrophic metabolism using blue green algae, Spirulina platensis. Blue green algae are photosynthetic unicellular prokaryotic organisms that live in diverse aquatic habitats ranging from cold salt water to tropical freshwater bodies (Vonshak, 2014).…”

“…1 Summary of Technological advances in the Produced Water treatment and Potential Applications to The Oil Sand Industry (Allen 20018) (Cabrera, 2008) (Eriksson, 2005;Gehringer et al, 1999) (Suzuki, et al, 2016) ................. Figure 2.13 Fatty Acid Biosynthesis process for Cyanobacteria.…”

Highly uniform platinum photodeposited hollow mesoporous titania nanoparticles for photocatalytic degradation of phenol

“…Thus, developing new methodologies and materials to treat wastewater is essential. Up to this point, treatments such as adsorption, 2,3 advanced oxidation processes (AOPs), 4,5 and wet oxidation 5 have been used. Moradi et al 6 performed batch adsorption experiments to study zeolite, nano zero-valent iron (nZVI)-zeolite, nZVI, and iron powder adsorbents on nitrate removal performance and researched their feasibility and strong pH dependence upon nitrate adsorption to adsorbents.…”