Ultrasonic destruction of phenol and substituted phenols: A review of current research

Abstract

Phenol and some of its derivatives such as chlorophenol and nitrophenol have received considerable attention from environmental scientists and engineers, due to their undesirable effects in the water environment, where they end up as a result of improper disposal methods. As a consequence, research has been conducted all around the world with the common goal of reducing their concentrations to allowable limits or converting them to non-toxic, non-hazardous forms that may easily be handled by natural decay processes. Some of this research has focused on ultrasonic techniques, which currently appears to present a convenient but as yet unproven method for large scale water remediation. The goal of this study is to identify and review some of these studies that are directly related with the use of ultrasound in decontaminating effluents with phenol residuals and to summarize the main points of interest and problems encountered.

Sonochemical Degradation of Phenol in the Presence of Inorganic Catalytic Materials

“…Further they may react with any of other free radicals present or with neutral molecules like O 2 and O 3 to produce peroxy species, superoxide, hydrogen peroxide or hydrogen. When the aqueous solution is saturated with O 2 , extra reactions exist due to reaction of molecular oxygen and hydrogen atom and thermal decomposition of oxygen [11]. Similarly, on mixing O 3 , some other reactions occur, augmenting the production of OH l radicals in aqueous and gas phase reaction [11].…”

One-pot, clean and energy efficient synthesis of dibenzo[b,f][1,4]oxazepine derivatives promoted by ultrasound

“…Some important therapeutically active dibenzoxazepines seems, development of a clean, mild, fast, inexpensive, and versatile method for the synthesis of the dibenzo[b,f] [1,4]oxazepines is necessary. Nowadays, the concept of speeding up the chemical transformations by ultrasound irradiation has created a lot of great interest in chemistry [19][20][21][22][23][24][25][26][27][28].…”

Influence of ultrasonic waves on the removal of different oil components from oily sludge

“…[7] Among them, ultrasonic cleaning, which has been applied widely to precision or critical cleaning, has shown strong promise. [8,9] Ultrasonic waves generate and evenly distribute cavitation implosions in a liquid medium. The released energy can reach and penetrate crevices, blind holes and areas that are normally inaccessible through other cleaning methods.…”