Oxidation technologies for water and wastewater treatment pages:73-73
Oxidation technologies for water and wastewater treatment edition:6 location:Goslar, Germany date:7-9 May 2012
Conventional water treatment methods cannot guarantee sufficient degradation of harmful organic compounds. An alternative purification technique is the use of ultrasonic waves combined with oxidants, leading to an advanced oxidation process (AOP). This study evaluates the use of high frequency ultrasonic waves as a singular AOP by comparing the degradation of polycyclic aromatic hydrocarbons (PAH’s), i.e., fluorene and phenanthrene, and the azo dye methyl orange. Tertiair butanol (TBA) was added as a radical scavenger to determine a general degradation mechanism for these pollutants. In addition, the effect of frequency (583, 860, 1040 kHz) and dissolved gas (air, argon, oxygen) has been studied. The study generally indicates that the ultrasonic process is a useful method to degrade volatile hydrophobic compounds. Furthermore, results demonstrate that compounds degrade by a combined mechanism of radical attack and combustive reactions, whereat the proportion of each reaction type is indirectly determined by the volatility and hydrophobicity of the compound. Finally, experiments showed that addition of gas to solutions containing hydrophobic compounds strips these pollutants to the air, thus transferring the pollutant problem.