لخّصلي

Water reclamation and reuse can be significant steps forward toward global sustainability.Commercially available corona discharge ozone generators involve the utilization of high voltage discharge in an oxygen (or air) containing cooled (or dried) gaseous phase with the following reactions in discharged gas (Rekhate & Srivastava, 2020), as belowCorona discharge ozone generator designed for lab scaling experiments was described by (Rubin, 1964).Later in 1965, Ireland and the United Kingdom (including Scotland) reported using ozone for color removal of Transformation of Traditional Wastewater Treatment Methods into Advanced Oxidation Processes and the Role of Ozonation Tamana Nikbeen1*, Ahmad Khalid Nayab1 1 Faculty of Chemical and Food Technology, The Slovak University of Technology in Bratislava, Radlinskeho 9, 812 37, Bratislava, Slovakia

• Corresponding author's e-mail: [email protected] ABSTRACT Technology advancement improves the quality of life, however, it might also introduce new pollutants to the ecosystem, which needs to deal with for the goal of a sustainable ecosystem.

Water reclamation and reuse can be significant steps forward toward global sustainability. Conventional wastewater treatment processes are not usually able to provide water with high standard quality, therefore, more effective treatments such as advanced oxidation processes (AOPs), including ozonation, are required for this purpose. Ozonation is commonly applied in wastewater reclamation facilities globally as an effective tertiary treatment procedure (Tang et al., 2014). At the present time, ozonation has been used for municipal wastewater quality enhancement for potable water reuse and environmental protection (Lim et al., 2022).
Firstly, what is ozone, and how has it found its way to wastewater treatment plants? The Dutch chemist, Van Muram, noticed an unusual odor during his laboratory experiments with his electrostatic machine in 1785. Later in 1839, it was discovered and made in a laboratory by German scientist Christian Friedrich Schönbein (McElroy & Fogal, 2008), and it was named ozone from the Greek word (ozein), which means to smell. Thomas Andrews showed in 1856 that only oxygen was involved in ozone formation, while a decade later (in 1865) Jacques-Louis Soret discovered the chemical formula of ozone.
German physician, Lender, published the first study regarding the practicality of ozone application for water disinfection and its biological effects in 1870, while for the very first time, it was Holland, where a water disinfection plant was built in 1893, which used ozone. Later in 1965, Ireland and the United Kingdom (including Scotland) reported using ozone for color removal of
Transformation of Traditional Wastewater Treatment Methods into Advanced Oxidation Processes and the Role of Ozonation
Tamana Nikbeen1*, Ahmad Khalid Nayab1
1 Faculty of Chemical and Food Technology, The Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia

• Corresponding author’s e-mail: [email protected]
  ABSTRACT
  Technology advancement improves the quality of life, however, it might also introduce new pollutants to the ecosystem, which needs to deal with for the goal of a sustainable ecosystem. Municipal and industrial wastewater has always been important in improving the quality of life while maintaining the sustainability of our planet simultaneously. The diversity of pollutants in wastewater requires more advanced and demanding treatment processes. The ozonation, as a crucial part of the advanced oxidation processes, is a superior oxidation method compared to traditional oxidation methods. After the recognition of ozone as GRAS (generally recognized as safe), its applications have diversified and is used currently for microbial inactivation, degradation of recalcitrant organic compounds, removal of a diverse range of micropollutants, solubilization and reduction of sludge, and removal of color and odor components in wastewaters treatment processes. However, some considerable challenges still exist towards its universal application, such as high ozone generation costs, diversity of pollutants, and formation of ozonation by-products, which still require further studies. The main theme of this review paper is the transformation of traditional oxidation methods into advanced oxidation processes and the role of ozonation in this regard, including its applications, by-products, and its comparison with the traditional oxidation methods and advanced oxidation processes.
  Keywords: wastewater treatment, traditional oxidation methods, ozonation, advanced oxidation processes, disinfection by-products, micropollutants.
  Journal of Ecological Engineering
  Received: 2023.03.01
  Accepted: 2023.04.17
  Published: 2023.05.01
  Journal of Ecological Engineering 2023, 24(6), 173–189
  https://doi.org/10.12911/22998993/162777
  ISSN 2299–8993, License CC-BY 4.0
  174
  Journal of Ecological Engineering 2023, 24(6), 173–189
  surface waters. Meanwhile, ozone-related researches
  in Switzerland were more focused on its
  applications for the oxidation of micropollutants
  and pesticides (History of Ozone, 2021).
  Ozone (O3) is a bluish gas with a pungent
  fishy smell under ambient temperature and pressure.
  It is an unstable and extremely reactive allotrope
  of oxygen, not storable (Psaltou & Zouboulis,
  2020), with powerful oxidizing properties,
  and capable of reacting with a large number of
  organic and inorganic compounds. Penetrability
  and its spontaneous decomposition to a non-toxic
  molecule, oxygen, are other features of ozone
  (Kim et al., 1999), which make it more desired.
  Some physical and chemical properties of ozone
  are presented in Table 1. Besides, the redox potentials
  of some common oxidizing agents are
  compared with ozone in the Table 2.
  Ozone generation is based on creating oxygen
  atoms by adding energy and splitting oxygen
  molecules and further attachment of single oxygen
  atoms to other oxygen molecules. The first
  ozone generator was proposed by Werner von
  Siemens in 1857 (Kogelschatz, 2003), which was
  based on an electrical discharge system. Principles
  of ozone generation are described by Wei
  et al. (2017), among which corona discharge and
  ultraviolet light principles are widely applied:
  • Gaseous discharge for ozone generation (corona
  discharge);
  • Photochemical ozone generation (ultraviolet
  light);
  • Phosphorus contact ozone generation;
  • Electrochemical ozone generation.
  Corona discharge ozone generator designed
  for lab scaling experiments was described by
  (Rubin, 1964). Three decades later, Sponholtz et
  al. (1999) developed a type of corona discharge
  ozone generator with simpler construction and
  with the possibility of assembling it from components
  commonly found in all laboratories of
  that time. In the early twentieth century, Park et
  al. (2006) designed an effective ozone generator
  by using a meshed-plate electrode in a dielectricbarrier
  discharge. Commercially available corona
  discharge ozone generators involve the utilization
  of high voltage discharge in an oxygen (or
  air) containing cooled (or dried) gaseous phase
  with the following reactions in discharged gas
  (Rekhate & Srivastava, 2020), as below