Ozonation improves physical attributes in domestic sewage effluent

Abstract

Root Zone Wastewater Treatment (RZWT) is an option of natural wastewater treatment widely studied throughout the world, being a technology based on physical, chemical and biological processes. However, there are some attributes in effluent that occasionally are not eliminated by RZWT. In this context, the use of ozone may contribute to mineralization, disinfection, detoxification, and, especially, color and turbidity removal. Ozone is an excellent oxidant, with great potential to reduce color, turbidity and other attributes in liquids, such as in wastewater treatment. This paper evaluated the effect of different ozone exposure times (0, 30, 60, 90, 120 and 150 minutes) and the application of different dosages of ozone (0, 4, 10, 17, 25 and 35 mg L-1 of O3) on Hydrogeonic Potential (pH), Electrical Conductivity (EC), Dissolved Oxygen (OD), Total Alkalinity (Alk.), Sodium (Na) and Potassium (K) in domestic sewage effluent treated by the RZWT. Different exposure times and ozone dosages did not influence the attributes Potassium, Sodium, Ammonia and Total Solids. Color and turbidity decreased, while pH, Alkalinity and Dissolved Oxygen increased at all exposure times and O3 dosages in relation to the non-ozonized effluent.

A simple system for ozone application in domestic sewage for agricultural reuse

“…Martínez et al (2011) also found no significant results in the removal of K in a study using ozone applied in wastewater, reporting its ineffectiveness against sulfates, nitrates, potassium, and sodium. Likewise, the results obtained by Camilo Júnior et al (2019) showed great homogeneity of the mean values of K as a function of the time of exposure of ozone to the effluent and the applied doses, indicating that ozonation does not influence its value.…”

“…This increase in the oxygenation rate occurs both as a result of the presence of oxygen in the ozone gas and because the O3 applied to the effluent is quickly converted into O2 due to its high solubility (Camilo Júnior et al, 2019).…”

“…However, treated sanitary sewage needs to meet adequate standards to enable its reuse in crops (Garay et al, 2021). In this sense, and specifically in terms of disinfection, ozone treatment has been used due to its strongly oxidizing character in inactivating several groups of microorganisms (Camilo Júnior et al, 2019), which allows the adjustment of effluent parameters. Ozone action is related to its interaction with different organic and organometallic functional groups in the samples, leading to disinfection and mineralization, with the removal of color and turbidity from the effluents.…”

“…Ozone action is related to its interaction with different organic and organometallic functional groups in the samples, leading to disinfection and mineralization, with the removal of color and turbidity from the effluents. The high oxidizing capacity of ozone also removes algae, iron and manganese, increasing the biodegradability of organic matter with the oxidation of specific pollutants (Camilo Júnior et al, 2019).…”

Ozonation as a pre-treatment of landfill leachate

“…The most studied components that influence the ozonation treatment are ozone dosage (Jung et al, 2017), exposure time to the gas (Camilo Júnior et al, 2019), pH value (Buffle et Ozonation as a pre-treatment of … Rev. Ambient.…”