The Use of Cavitating Jets to Oxidize Organic Compounds in Water

Kalumuck, Kenneth; Chahine, Georges L.

doi:10.1115/1.1286993

Cited by 137 publications

(71 citation statements)

References 17 publications

(7 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hydrodynamic cavitation is more flexible, easily scaled up, and more efficient [8,9,42]. However, most of the previous ultrasonic investigations were carried out with small volumes of liquids (50-1500 mL) at 20-40 kHz, while the hydrodynamic investigations were performed in very large volumes of liquids (5-50 L) [9, 15-17 ,30].…”

Section: Comparison Of Energy Efficiencies Between Ultrasonic and Hydmentioning

confidence: 99%

“…Recently, a comparison between hydrodynamic and sonochemical reactors has been reviewed by citing different reactions, e.g., oxidation of toluene, xylene, mesitylene, nitrotoluene, chlorotoluene, and synthesis of biodiesel [9,28]. The efficacy of hydrodynamic cavitation reactors has been conclusively shown to be better than ultrasonic bath reactors [8,9,29]. However, earlier investigations on the chemical effects of hydrodynamic cavitation were carried out at very high upstream pressure (10-150 MPa) [7,10] or at pilot-plant scale (50-100 L) [29,30].…”

mentioning

confidence: 98%

See 1 more Smart Citation

Degradation of Chlorocarbons Driven by Hydrodynamic Cavitation

Ondruschka

Bräutigam

2007

Chem Eng & Technol

View full text Add to dashboard Cite

To provide an efficient lab-scale device for the investigation of the degradation of organic pollutants driven by hydrodynamic cavitation, the degradation kinetics of chloroform and carbon tetrachloride and the increase of conductivity in aqueous solutions were measured. These are values which were not previously available. Under hydrodynamic cavitation conditions, the degradation kinetics for chlorocarbons was found to be pseudo first-order. Meanwhile, C-H and C-Cl bonds are broken, and Cl 2 , Cl . , Cl -and other ions released can increase the conductivity and enhance the oxidation of KI in aqueous solutions. The upstream pressures of the orifice plate, the cavitation number, and the solution temperature have substantial effects on the degradation kinetics. A decreased cavitation number can result in more cavitation events and enhances the degradation of chlorocarbons and/or the oxidation of KI. A decrease in temperature is generally favorable to the cavitation chemistry. Organic products from the degradation of carbon tetrachloride and chloroform have demonstrated the formation and recombination of free radicals, e.g., CCl 4 , C 2 Cl 4 , and C 2 Cl 6 are produced from the degradation of CHCl 3 . CHCl 3 and C 2 Cl 6 are produced from the degradation of CCl 4 . Both the chemical mechanism and the reaction kinetics of the degradation of chlorocarbons induced by hydrodynamic cavitation are consistent with those obtained from the acoustic cavitation. Therefore, the technology of hydrodynamic cavitation should be a good candidate for the removal of organic pollutants from water. IntroductionCavitation is the formation, growth, and implosive collapse of gas or vapor-filled bubbles in liquids [1]. Turbulent flow, laser, electrical discharge, boiling, radiolysis, and ultrasonic irradiation can cause cavitational bubbles. The collapse of cavities generates extreme energy for chemical and mechanical effects. It has been experimentally estimated that extreme conditions exist inside the medium for an extremely short time, e.g., temperatures of about 5000°C and pressures of ca. 50-100 MPa exist inside the collapsing cavity [2,3].Hydrodynamic cavitation is produced by pressure variations in a flowing liquid due to the geometry of the system. It can simply be generated by a rotating propeller blade, high-speed homogenizer and jet fluidizer (e.g., the high-velocity passage of the liquid through a constriction such as a throttling valve, orifice plate, and venturi). Although light emission from hydrodynamic cavitations was observed in the 1960's [4], the chemical effects of hydrodynamic cavitation have only been properly investigated since 1993 [5][6][7][8][9]. Hydrodynamic cavitation has been recently employed in the preparation of nanostructured materials [10,11], the removal of chemicals from wastewater treatment [12][13][14][15][16][17][18][19], water disinfection [20], and the degradation of polymers [21,22].Chlorocarbons consist of chloromethane, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, tetra...

show abstract

Section: Comparison Of Energy Efficiencies Between Ultrasonic and Hydmentioning

confidence: 99%

mentioning

confidence: 98%

Degradation of Chlorocarbons Driven by Hydrodynamic Cavitation

Ondruschka

Bräutigam

2007

Chem Eng & Technol

View full text Add to dashboard Cite

show abstract

“…Most of these above-mentioned problems involve large bubble volume changes due to boiling, cavitation and/or bubble breakup and coalescence. Particularly, in liquid phase oxidation processes such as injection of oxygen into liquid (Kalumuck & Chahine, 2000) an explosion behavior occurs, followed by the emission of high-peak spherical pressure waves which propagates through the surrounding bubbly liquid. In these kinds of problems, shock and pressure wave propagation in bubbly media, the dynamics, relative motion, and interaction of bubbles with the surroundings play crucial roles on the process in question and require accurate modeling, which poses fundamental challenges.…”

Section: Introductionmentioning

confidence: 99%

Spherical bubble dynamics in a bubbly medium using an Euler–Lagrange model

Chahine

Hsiao

2015

Chemical Engineering Science

View full text Add to dashboard Cite

For applications involving large bubble volume changes such as in cavitating flows and in bubbly two-phase flows involving shock and pressure wave propagation, the dynamics, relative motion, deformation, and interaction of bubbles with the surrounding medium play crucial roles and require accurate modeling. We present in this paper a fundamental study of the dynamic oscillations of a 'primary' bubble in a bubbly mixture using a two-way coupled Euler-Lagrange model. It addresses a simplified spherical configuration while using the full three-dimensional code. A main objective of the study is to investigate how the dynamics of a 'primary' bubble is affected by the presence of a surrounding bubbly medium and how it differs from its behavior in a pure liquid. This The simulations clearly indicate that the surrounding microbubbles absorb energy emitted from the primary bubble during its oscillations. This results in a reduction of the maximum radius and the period of oscillations of the primary bubble as compared to the dynamics in the pure liquid. Also, accounting for the dynamics of the field bubbles brings out the presence in the two-phase medium of a phase shift between density and pressure distributions. Such a shift is not captured by two-phase homogeneous medium models. These effects increase with increase in the mixture void fraction and in the initial bubble sizes in the mixture. The numerical observations are found to be in good qualitative agreements with previously published experimental data (Jayaprakash et al., 2011) investigating spark generated bubble dynamics in a bubbly medium.

show abstract

“…The hydroxyl radicals are produced during the decomposition of complex organic substances at high local temperatures (Petrier and Francony 1997). The application of the hydrodynamic cavitation phenomenon to activated sludge disintegration -cell structure disruption -has been investigated by many authors (Kalumuck 2000, Gogate and Pandit 2005, Suschka et al 2007a, 2007b, Grübel 2007.…”

Section: Introductionmentioning

confidence: 99%

Alkaline solubilisation of waste activated sludge (WAS) for soluble organic substrate – (SCOD) production / Tworzenie się rozpuszczalnego substratu organicznego podczas zasadowego rozpuszczania osadów ściekowych

Suschka¹,

Kowalski²,

Mazierski³

et al. 2015

Archives of Environmental Protection

View full text Add to dashboard Cite

Improving the effects of hydrolysis on waste activated sludge (WAS) prior to anaerobic digestion is of primary importance. Several technologies have been developed and partially implemented in practice. In this paper, perhaps the simplest of these methods, alkaline solubilization, has been investigated and the results of hydrolysis are presented. An increase to only pH 8 can distinctively increase the soluble chemical oxygen demand (SCOD), and produce an anaerobic condition effect favorable to volatile fatty acids (VFA) production. Further increases of pH, up to pH 10, leads to further improvements in hydrolysis effects. It is suggested that an increase to pH 9 is suffi cient and feasible for technical operations, given the use of moderate anti-corrosive construction material. This recommendation is also made having taken in consideration the option of using hydrodynamic disintegration after the initial WAS hydrolysis process. This paper presents the effects of following alkaline solubilization with hydrodynamic disintegration on SCOD.

show abstract

The Use of Cavitating Jets to Oxidize Organic Compounds in Water

Cited by 137 publications

References 17 publications

Degradation of Chlorocarbons Driven by Hydrodynamic Cavitation

Degradation of Chlorocarbons Driven by Hydrodynamic Cavitation

Spherical bubble dynamics in a bubbly medium using an Euler–Lagrange model

Alkaline solubilisation of waste activated sludge (WAS) for soluble organic substrate – (SCOD) production / Tworzenie się rozpuszczalnego substratu organicznego podczas zasadowego rozpuszczania osadów ściekowych

Contact Info

Product

Resources

About