The influence of contact zone configuration on the flow structure in a dissolved air flotation pilot plant

Lundh, Måns; Jönsson, Lennart; Dahlquist, Jan

doi:10.1016/s0043-1354(01)00357-8

Cited by 46 publications

(21 citation statements)

References 10 publications

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“…According to the study by Han and Kim (2001), maximum adhesion efficiency was achieved when the floc sizes and microbubble sizes were similar. Taking into the consideration that the diameter of the microbubble floatation typically is 10 to 100 mm (an average of 40 mm) (Kiuru, 2001;Lundh et al, 2002), the sizes of the floc-micron particles in the range 10 to 100 mm should be sufficient.…”

Section: Resultsmentioning

confidence: 99%

Improved Pretreatment (Coagulation‐Floatation and Ozonation) of Younger Landfill Leachate by Microbubbles

Shu

Zhai

Huang

et al. 2010

Water Environment Research

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A novel microbubble air/ozone floatation device, TCRI, was developed to enhance the combination of the coagulation and ozonation processes as the pretreatment of landfill leachate. In the coagulation process, microbubble floatation reduced the coagulant dosage. The removal efficiencies of chemical oxygen demand (COD), color, nitrate, and ammonia for the coagulation microbubble floatation were 97, 20, 47, and 163% higher, respectively, than those of the coagulationsedimentation process; in the ozonation process, the removal efficiencies of ammonia and COD in microbubble ozonation were increased by 300 and 200%, respectively, compared with a conventional ozonation contactor when the ozonation time was 60 minutes. The results showed that microbubbles could reach a higher ozone-transfer rate (microbubbles 5 0.3018 min 21 . conventional ozone bubbles 5 0.2014 min 21 ). Therefore, the application of the microbubble technology in the coagulation and ozonation combination process may provide an effective and low-cost approach for wastewater treatment. Water Environ. Res., 82, 657 (2010).

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Section: Resultsmentioning

confidence: 99%

Improved Pretreatment (Coagulation‐Floatation and Ozonation) of Younger Landfill Leachate by Microbubbles

Shu

Zhai

Huang

et al. 2010

Water Environment Research

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“…Assim, na ZC ocorre a colisão e a agregação das micro-bolhas de ar nos flocos. A zona de separação (ZS) por sua vez, é a região onde as condições de escoamento devem favorecer a manutenção da ligação e propiciar a ascensão do conjunto micro-bolhas e flocos até a superfície da ZS (Lundh;Jönsson;Dahlquist, 2002).…”

Section: Revista Dae Janeiro-abril 2014 Nº194unclassified

Estudo Hidrodinâmico Quali-Quantitativo de uma unidade de flotação por ar dissolvido (FAD): O efeito do dispositivo de coleta de água flotada

Reali¹,

Moruzzi²

2014

RDAE

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ResumoO foco desse artigo foi à investigação de sistema de coleta de água de uma unidade de flotação por ar dissolvido (FAD) em escala piloto. Duas opções de coleta foram estudadas: (i) dispositivo Tipo 1, constituído de tubulação perfurada (manifold) situada próximo á superfície da região de saída da unidade FAD, após o anteparo final da mesma, e; (ii) Tipo 2, constituído de placa tipo "fundo falso" contendo orifícios e situada no fundo da zona de separação (ZS) da unidade FAD. Foram realizados ensaios qualitativos com imagens e ensaios tipo estímulo-resposta com injeção de traçador na forma de perturbação impulso. Os resultados dos ensaios parametrizados foram ajustados conforme modelos uniparamétricos de tanques em série (N-CSTR) e de dispersão de pequena (DPI) e de grande intensidade (DGI). O dispositivo Tipo 2 ("fundo falso" com orifícios) foi o mais adequado, proporcionando melhor distribuição das linhas de corrente e menor volume de zonas mortas no interior da ZS. Os resultados apontam que o modelo de tanques em série foi mais apropriado para descrever o comportamento hidrodinâmico da unidade de FAD investigada.Palavras-chave: FAD, sistema de coleta, hidrodinâmica. AbstractThe main article aim was to investigate the collecting system of a dissolved air flotation (DAF) unit in pilot scale. Referring to the collecting system position, two options were analyzed: (i) top manifold and (ii) bottom manifold, pipes or plates. Qualitative and quantitative essays were performed, as image and stimulusresponse tests, respectively. The results of the essays standardized were adjusted by N-continuous stirred tank reactors in series and theoretical models of dispersion (low and high). The bottom manifold (plates with orifices) was more appropriate. The results pointed out that the N-continuous stirred tank reactors in series model was more adequate to describe the hydrodynamic behavior of the DAF unit.

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“…It is noted that the microbubble pump is able to remove water-soluble gases effectively in chemical plant environments without complicated processes [19]. Also, it has the potential to replace the bubble generator applied to conventional dissolved air flotation (DAF) systems and has an advantage in terms of operating cost and energy saving [20].…”

Section: Introductionmentioning

confidence: 99%

Bubble Size and Bubble Concentration of a Microbubble Pump with Respect to Operating Conditions

2018

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Abstract:The present paper describes some aspects of the bubble size and concentration of a microbubble pump with respect to flow and pressure conditions. The microbubble pump used in the present study has an open channel impeller of a regenerative pump, which generates micro-sized bubbles with the rotation of the impeller. The bubble characteristics are analyzed by measuring the bubble size and concentration using the experimental apparatus consisting of open-loop facilities; a regenerative pump, a particle counter, electronic flow meters, pressure sensors, flow control valves, a torque meter, and reservoir tanks. To control the intake, and the air flowrate upstream of the pump, a high precision flow control valve is introduced. The bubble characteristics have been analyzed by controlling the intake air flowrate and the pressure difference of the pump while the rotational frequency of the pump impeller was kept constant. All measurement data was stored on the computer through the NI (National Instrument) interface system. The bubble size and concentration are mainly affected by three operating parameters: the intake air flowrate, the pressure difference, and the water flowrate supplied to the pump. It is noted that the operating conditions that can most effectively generate microbubbles in the range of 20 to 30 micrometers are at the pressure of 5 bar and at the air flowrate ratio of 4.0 percent for the present pump. Throughout the experimental measurements, it was found that the pump efficiency changed by less than 1.2 percent, depending on the intake air supply. The performance characteristics of microbubble generation obtained by experimental measurements are analyzed and discussed in detail.

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The influence of contact zone configuration on the flow structure in a dissolved air flotation pilot plant

Cited by 46 publications

References 10 publications

Improved Pretreatment (Coagulation‐Floatation and Ozonation) of Younger Landfill Leachate by Microbubbles

Improved Pretreatment (Coagulation‐Floatation and Ozonation) of Younger Landfill Leachate by Microbubbles

Estudo Hidrodinâmico Quali-Quantitativo de uma unidade de flotação por ar dissolvido (FAD): O efeito do dispositivo de coleta de água flotada

Bubble Size and Bubble Concentration of a Microbubble Pump with Respect to Operating Conditions

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