Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration
A bioreactor refers to any manufactured or engineered device that supports a biologically active environment. These kinds of reactors are designed to treat wastewater treatment. Volumetric mass transfer coefficient and the effect of superficial gas velocity, as the most important operational factor...
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| Format: | Article |
| Language: | English |
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Iranian Research Organization for Science and Technology (IROST)
2017-06-01
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| Series: | Advances in Environmental Technology |
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| Online Access: | http://aet.irost.ir/article_454_6223331d7fc204be63a7b928f5c9bb51.pdf |
| _version_ | 1818383738995736576 |
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| author | Mohammad Ali Salehi Nasrin Hakimghiasi |
| author_facet | Mohammad Ali Salehi Nasrin Hakimghiasi |
| author_sort | Mohammad Ali Salehi |
| collection | DOAJ |
| description | A bioreactor refers to any manufactured or engineered device that supports a biologically active environment. These kinds of reactors are designed to treat wastewater treatment. Volumetric mass transfer coefficient and the effect of superficial gas velocity, as the most important operational factor on hydrodynamics, in three-phase airlift reactors are investigated in this study. The experiments for the external airlift reactor were carried out at a 0.14 downcomer to riser cross-sectional area ratio, and for the internal reactor at 0.36 and 1. Air and water were used as the gas and liquid phases, respectively, as well as activated carbon/sludge particles as the solid phase. Increasing the superficial gas velocity resulted in greater liquid circulation velocity, gas hold-up, and volumetric mass transfer coefficient; increasing the suspended activated carbon particles resulted in a decreased concentration of activated sludge, downcomer to riser cross sectional area ratio, liquid velocity, gas hold-up and volumetric mass transfer coefficient. The maximum gas hold-up was 0.178 which was attained in the external airlift reactor with a 1 Wt. % of activated sludge at a gas superficial velocity of 0.25 (m/s). The maximum volumetric mass transfer coefficient was 0.0485 (l/s) that was observed in the external airlift reactor containing activated carbon with a 0.00032 solid hold-up. A switch was observed in the activated sludge airlift reactor flow regime at gas velocities higher than 0.15 (m/s) and 0.18 (m/s) in the activated carbon airlift reactors. |
| first_indexed | 2024-12-14T03:11:09Z |
| format | Article |
| id | doaj.art-a06c189d8b7943c8af50f480cceafca9 |
| institution | Directory Open Access Journal |
| issn | 2476-6674 2476-4779 |
| language | English |
| last_indexed | 2024-12-14T03:11:09Z |
| publishDate | 2017-06-01 |
| publisher | Iranian Research Organization for Science and Technology (IROST) |
| record_format | Article |
| series | Advances in Environmental Technology |
| spelling | doaj.art-a06c189d8b7943c8af50f480cceafca92022-12-21T23:19:16ZengIranian Research Organization for Science and Technology (IROST)Advances in Environmental Technology2476-66742476-47792017-06-012417918410.22104/aet.2017.454454Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtrationMohammad Ali Salehi0Nasrin Hakimghiasi1Department of Chemical Engineering, University of GuilanMsc, Department of Chemical Engineering, Guilan University, Rasht, IranA bioreactor refers to any manufactured or engineered device that supports a biologically active environment. These kinds of reactors are designed to treat wastewater treatment. Volumetric mass transfer coefficient and the effect of superficial gas velocity, as the most important operational factor on hydrodynamics, in three-phase airlift reactors are investigated in this study. The experiments for the external airlift reactor were carried out at a 0.14 downcomer to riser cross-sectional area ratio, and for the internal reactor at 0.36 and 1. Air and water were used as the gas and liquid phases, respectively, as well as activated carbon/sludge particles as the solid phase. Increasing the superficial gas velocity resulted in greater liquid circulation velocity, gas hold-up, and volumetric mass transfer coefficient; increasing the suspended activated carbon particles resulted in a decreased concentration of activated sludge, downcomer to riser cross sectional area ratio, liquid velocity, gas hold-up and volumetric mass transfer coefficient. The maximum gas hold-up was 0.178 which was attained in the external airlift reactor with a 1 Wt. % of activated sludge at a gas superficial velocity of 0.25 (m/s). The maximum volumetric mass transfer coefficient was 0.0485 (l/s) that was observed in the external airlift reactor containing activated carbon with a 0.00032 solid hold-up. A switch was observed in the activated sludge airlift reactor flow regime at gas velocities higher than 0.15 (m/s) and 0.18 (m/s) in the activated carbon airlift reactors.http://aet.irost.ir/article_454_6223331d7fc204be63a7b928f5c9bb51.pdfairlift reactoractivated sludgeactivated carbonmass transfergas superficial velocity |
| spellingShingle | Mohammad Ali Salehi Nasrin Hakimghiasi Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration Advances in Environmental Technology airlift reactor activated sludge activated carbon mass transfer gas superficial velocity |
| title | Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration |
| title_full | Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration |
| title_fullStr | Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration |
| title_full_unstemmed | Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration |
| title_short | Hydrodynamics and mass transfer inthree-phase airlift reactors for activated Carbon and sludge filtration |
| title_sort | hydrodynamics and mass transfer inthree phase airlift reactors for activated carbon and sludge filtration |
| topic | airlift reactor activated sludge activated carbon mass transfer gas superficial velocity |
| url | http://aet.irost.ir/article_454_6223331d7fc204be63a7b928f5c9bb51.pdf |
| work_keys_str_mv | AT mohammadalisalehi hydrodynamicsandmasstransferinthreephaseairliftreactorsforactivatedcarbonandsludgefiltration AT nasrinhakimghiasi hydrodynamicsandmasstransferinthreephaseairliftreactorsforactivatedcarbonandsludgefiltration |