Use of Ultrasound as an Advanced Oxidation Process for the Degradation of Emerging Pollutants in Water

Abstract

Emerging pollutants are compounds of increased environmental importance and, as such there is interest among researchers in the evaluation of their presence, continuity and elimination in different environmental matrices. The present work reviews the available scientific data on the degradation of emerging pollutants, mainly pharmaceuticals, through ultrasound, as an advanced oxidation process (AOP). This study analyzes the influence of several parameters, such as the nature of the pollutant, the ultrasonic frequency, the electrical power, the pH, the constituents of the matrix and the temperature of the solution on the efficiency of this AOP through researches previously reported in the literature. Additionally, it informs on the application of the referred process alone and/or in combination with other AOPs focusing on the treatment of domestic and industrial wastewaters containing emerging pollutants, mainly pharmaceuticals, as well as on the economic costs associated with and the future perspectives that make ultrasound a possible candidate to solve the problem of water pollution by these emerging pollutants.

A review on pharmaceuticals removal from waters by single and combined biological, membrane filtration and ultrasound systems

“…Increasing solution temperature can increase pharmaceutical removal by reducing cavitation threshold and thus, increase HO • production [40] , [136] . That is, increasing solution temperature is expected to increase reaction rates, increasing removal rates of e.g.…”

“…That is, increasing solution temperature is expected to increase reaction rates, increasing removal rates of e.g. DCF [118] , SMX and IBP [40] . However, Sutar et al [137] showed using DCF that there exists a temperature threshold of 50 °C, above which increasing solution temperature reduced the degradation efficiency from 100% to below 20%.…”

“…Several review papers have been published discussing the performance of US on pharmaceuticals removal, either as the main topic of the paper [39] , [40] , [41] , [42] , [43] , [44] or integrated into a more general analysis on advanced oxidation processes [9] , [45] , [46] , [47] , however there is very little literature incorporating membrane filtration systems. Therefore, the objective of the present review is to showcase biological, US-based AOPs and membrane filtration, individually and discuss the potential benefits in combining these three processes for the removal of pharmaceuticals from water and wastewater, highlighting the potential of the hybrid systems and underlining research gaps for future studies.…”

A review on the potential of photocatalysis in combatting SARS-CoV-2 in wastewater

“…This technique has attracted wide attention in water and sewage system due to simplicity, high decomposition speed, and zero secondary pollution. Ultrasound is evaluated as one of the AOP for the degradation of pollutants in the water system due to the formation of free hydroxyl radicals with oxidising capabilities [ 50 , 51 ]. Ultrasound technique was reported to disinfect microorganisms and viruses by several mechanisms based on acoustic cavitation [ 49 , 52 , 53 ].…”

Ultrasound as an Advanced Oxidative Process: A Review on Treating Pharmaceutical Compounds

“…It covers the main results and limitations of each method. Another review focused on the use of ultrasound as AOP 40. The authors analyze and discuss the potential risks and implications and also describe the associated economic costs and future prospects for using ultrasound to resolve/minimize water pollution by emerging pollutants.…”