A Review on Additives-assisted Ultrasound for Organic Pollutants Degradation

Ultrasonic-assisted ozone degradation of organic pollutants in industrial sulfuric acid

“…The degradation of organic pollutants using US alone mainly depends on the generation of hydroxyl radicals during acoustic cavitation. Hydroxyl radicals are generated when ultrasound waves are transmitted through an aqueous solution (Reaction (5) ) [47] . However, in the concentrated sulfuric acid system with low water content (<2 wt%), very few hydroxyl radicals are formed from water cavitation bubbles [48] .…”

A Critical Review on Removal of Gaseous Pollutants Using Sulfate Radical-based Advanced Oxidation Technologies

“…Ultrasonic activation technology utilizes ultrasound to generate an oxidative medium via acoustic cavitation because of the formation and collapse of microbubbles from the acoustical wave-induced compression/rarefaction. − The collapse of these microbubbles will form local transient high temperatures (≥5000 K) and high pressures (≥1000 atm), which lead to the generation of highly reactive species such as •OH and SO 4 • – in water or solution by cleaving the molecular bond in PS and PMS (see Table ). − Compared with the short effective propagation distance of UV-light in solution, ultrasonic activation technology has a longer effective propagation distance in water, which is more suitable for the treatment of solutions containing particles. Many results − have demonstrated the effectiveness of ultrasonic activation technology for the degradation of organic pollutants from wastewater as a sole means of treatment or in combination with other activation technologies.…”

“… − Compared with the short effective propagation distance of UV-light in solution, ultrasonic activation technology has a longer effective propagation distance in water, which is more suitable for the treatment of solutions containing particles. Many results − have demonstrated the effectiveness of ultrasonic activation technology for the degradation of organic pollutants from wastewater as a sole means of treatment or in combination with other activation technologies.…”

“…Many results − ,− indicated that ultrasonic activation technology is an inefficient activation means for the production of free radicals in water or solutions, and has high energy consumption owing to its low electro-acoustic conversion efficiency, as compared with other activation methods. Besides, ultrasonic device, especially with high energy density, has high investment cost and short life of key equipment such as piezoelectric ceramics and emitters.…”

Review on Removal of SO2, NOx, Mercury, and Arsenic from Flue Gas Using Green Oxidation Absorption Technology

“…Sonochemical removal technology utilizes ultrasonic sound to produce an oxidative medium through acoustic cavitation owing to the formation and instant collapse of microbubbles. , The instant collapse of microbubbles will lead to local transient high temperatures and high pressures (≥5000 K and ≥1000 atm), resulting in the generation of highly reactive species such as ·OH radicals in water (see Table ). , In addition, when peroxide is present in water, ultrasound can also directly cleave the peroxide bonds in peroxides (H 2 O 2 , PS, and PMS) to produce free radicals such as ·OH and SO 4 – · in solution. ,,, Compared with the short effective propagation distance of UV light in water (about 2–10 cm depending on water quality), sonochemical technology has a much longer effective propagation distance in water (about 10–50 cm depending on water quality), which is more suitable for the treatment of turbid solutions or solutions containing particles. This is of great practical significance because there are many impurities or particles in the actual natural water and flue gas.…”