Physical insights into the sonochemical degradation of recalcitrant organic pollutants with cavitation bubble dynamics

Sivasankar, Thirugnanasambandam; Moholkar, Vijayanand S.

doi:10.1016/j.ultsonch.2009.02.009

Cited by 128 publications

(56 citation statements)

References 45 publications

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“…The results of this work confirm this aspect and agree well with similar observations in the literature [21,22]. However, it should be noted that no such systematic studies have been reported in the literature on the degradation of different solvents using hydrodynamic cavitation though some single component studies were reported using conventional cavitating devices such as an orifice.…”

Section: Effect Of Nature Of Solventsupporting

confidence: 92%

Solvent degradation studies using hydrodynamic cavitation

Suryawanshi

Bhandari

Sorokhaibam

et al. 2017

Env Prog and Sustain Energy

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Hydrodynamic cavitation for the degradation of organic solvents was investigated in detail using a newer form of cavitating device-vortex diode. The results were also compared with that using conventional cavitating device orifice. Removal of three different organic solvents-acetone, methyl ethyl ketone (MEK), and toluene were studied on a pilot plant with capacity of 1 m 3 /h. The effect of different operating parameters such as inlet pressure, initial concentration, and reactor type on the degradation rate of solvent was investigated in detail. The results revealed that efficiency of solvent removal varies substantially with the change in physical operating conditions and nature of the solvent. It was found that up to 80% degradation could be achieved for toluene (cavitational yield 32.2 3 10 23 mg/J), substantially higher than that for acetone and MEK indicating the effect of molecular weight/structure in the degradation process. Further, the results clearly indicated chemical oxidation as a predominant mechanism for degradation and not physical destruction. Vortex diode that works on the principle of vortex generation for cavitation, was found to be far superior over conventional cavitating device-orifice-up to eight times higher cavitational yield could be obtained for toluene as compared to orifice. The results of this study provide newer insight into solvent removal using hydrodynamic cavitation and would have bearing on the treatment of solvent containing wastewaters.

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Section: Effect Of Nature Of Solventsupporting

confidence: 92%

Solvent degradation studies using hydrodynamic cavitation

Suryawanshi

Bhandari

Sorokhaibam

et al. 2017

Env Prog and Sustain Energy

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“…Since the C p /C v ratio of N 2 (g) is high (1.543) the bubble diameter increase during cavitation process resulting in high OH· ions (Mendez-Arriaga et al 2008;Psillakis et al 2003). In this study, it was found that N 2 (g) increase the OH· ions through sonication of less hydrophobic PAHs (data not shown) by increasing the temperature and bubble diameter as reported by Sivasankar and Moholkar (2009).…”

Section: Effect Of Aeration On the Removal Of Pah At Increasing Sonicsupporting

confidence: 55%

Effectiveness of Air, N2 (gas), Fe+3 and Fe3O4 Nanoparticles on the Sonication of Less and More Hydrophobic Polycyclic Aromatic Hydrocarbons (PAHs) and Toxicity

Sponza

Özteki̇n

2011

Water Air Soil Pollut

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In this study, the effects of 1 h aeration, nitrogen gas N 2 (g) sparging (15 and 30 min) and increasing ferric ions (Fe +3 ) as FeSO 4 (10, 20 and 50 mg L −1 ) and Fe 3 O 4 nanoparticles (1, 2 and 4 gL −1 ) concentrations on three less hydrophobic and three more hydrophobic polycyclic aromatic hydrocarbons (PAHs) and toxicity removals from a petrochemical industry in Izmir (Turkey) were investigated in a sonicator with a power of 650 W and an ultrasound frequency of 35 kHz; 1 h aeration increased the yields in benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene PAHs (less hydrophobic) from 62% to 67% to around 95-97% after 150 min sonication at 60°C. However, 1 h aeration did not contribute to the yields of more hydrophobic PAHs (indeno[1,2,3-cd] pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene). The maximum yields were obtained at acidic and alkaline pH for more and less hydrophobic PAHs, respectively, after 60 and 120 min sonication at 30°C; 30 min N 2 (g) sparging, 50 mg L −1 Fe +3 increased the yields of less hydropobic PAHs after 150 min sonication at 60°C. Two milligrams per liter of Fe 3 O 4 nanoparticles increased both less (87-88%) and more (96-98%) hydrophobic PAH yields. The Daphnia magna acute toxicity test showed that the toxicity decreased significantly with an hour aeration, 30 min N 2 (g) sparging, 50 mg L −1 Fe +3 and 2 gL −1 Fe 3 O 4 nanoparticles at 60°C after 120 and 150 min sonications. Vibrio fischeri was found to be more resistant to the sonicated samples than D. magna. Significant correlations were found between the physicochemical properties of sonicated PAHs and acute toxicities both organisms.

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“…We attribute this result to the presence of oxygen in air bubble that conserves the radicals formed out of dissociation of water vapor. 27,28 3. With rise in static pressure to 200 kPa (or 2 bar), both chemical and physical effects of cavitation bubbles get eliminated.…”

Section: Simulations Resultsmentioning

confidence: 99%

“…27,28 The dissolved oxygen can help conservation of the • OH radicals generated through Fenton reactions as well as cavitation bubbles through following reaction…”

Section: Contemplations and Conjecturesmentioning

confidence: 99%

Physical mechanism of sono‐Fenton process

2013

Self Cite

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Hybrid advanced oxidation processes (AOPs), where two or more AOPs are applied simultaneously, are known to give effective degradation of recalcitrant organic pollutants. This article attempts to discern the physical mechanism of the hybrid sono-Fenton process with identification of links between individual mechanism of the sonolysis and Fenton process. An approach of coupling experimental results with simulations of cavitation bubble dynamics has been adopted for two textile dyes as model pollutants. Fenton process is revealed to have greater contribution than sonolysis in the overall decolorization of both dyes. H 2 O 2 added to the liquid medium as a Fenton reagent scavenges• OH radicals produced by cavitation bubbles. Addition of only H 2 O 2 to the medium during sonolysis does not yield marked difference in decolorization. Elimination of transient cavitation with application of elevated static pressure to the medium does not alter the extent of decolorization. The synergy between sonolysis and Fenton process is, thus, revealed to be negative. The dissolved oxygen in the medium is found to play an important role in decolorization through conservation of oxidizing radicals.

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Physical insights into the sonochemical degradation of recalcitrant organic pollutants with cavitation bubble dynamics

Cited by 128 publications

References 45 publications

Solvent degradation studies using hydrodynamic cavitation

Solvent degradation studies using hydrodynamic cavitation

Effectiveness of Air, N2 (gas), Fe+3 and Fe3O4 Nanoparticles on the Sonication of Less and More Hydrophobic Polycyclic Aromatic Hydrocarbons (PAHs) and Toxicity

Physical mechanism of sono‐Fenton process

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