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Akira Hafuka - One of the best experts on this subject based on the ideXlab platform.
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direct membrane filtration dmf for recovery of organic matter in municipal wastewater using small amounts of chemicals and energy
Chemosphere, 2021Co-Authors: Katsuki Kimura, Mutsumi Yamakawa, Akira HafukaAbstract:Abstract The recovery and utilization of organic matter in municipal wastewater are essential for the establishment of a sustainable society, such that these factors have drawn significant recent attention. The up-concentration of organic matter via direct membrane filtration (DMF), followed by anaerobic digestion, is advantageous over the treatment of the entire wastewater by an anaerobic process, such as an anaerobic membrane bioreactor (AnMBR). However, the occurrence of severe membrane fouling in the DMF is a problem. In this study, DMF was carried out at an existing wastewater treatment plant to attempt long-term operation. A combination of vibration of membrane modules, short-term aeration, and chemically enhanced backwash (CEB), with multiple chemicals (i.e., the alternative use of citric acid and NaClO), was found to be effective for the mitigation of membrane fouling in DMF. Furthermore, switching the feed from influents to effluents in the primary Sedimentation Basin significantly mitigated membrane fouling. In this study, in which microfiltration membrane, with a nominal pore size of 0.1 μm, was used, ∼75% of the organic matter in raw wastewater was recovered, with the volumetric concentration of wastewater by 50- or 150-fold. Organic matter recovered by DMF had significantly higher potentials for biogas production than the excess sludge generated from the same wastewater treatment plant. An analysis of the energy balance (i.e., the energy used for DMF and recovered by DMF) suggests that the proposed DMF can produce a net-positive amount of electricity of ∼0.3 kWh from 1 m3 of raw wastewater with a typical strength (chemical oxygen demand of 500 mg/L).
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anaerobic digestibility of up concentrated organic matter obtained from direct membrane filtration of municipal wastewater
Biochemical Engineering Journal, 2020Co-Authors: Akira Hafuka, Taketsugu Takahashi, Katsuki KimuraAbstract:Abstract Direct membrane filtration (DMF) process is a promising technology for up-concentration and recovery of organic matter (OM) from municipal wastewater. This study investigates anaerobic digestibility of up-concentrated OM obtained from the DMF process. Effluent from a primary Sedimentation Basin was used as feed water. Effect of polyaluminum chloride (PACl) addition to the DMF process on the anaerobic digestibility of obtained up-concentrated OM was also investigated because PACl is sometimes used as a coagulant in the DMF process for improving effluent quality and OM recovery, and for mitigating membrane fouling. Batch anaerobic digestion experiments were conducted to achieve these objectives. Fitting the obtained data to the reaction curve model revealed that maximum biogas production based on feed volatile solids (VSfed) from up-concentrated OM containing PACl reached 0.56 L-Biogas/g-VSfed, which was higher than from up-concentrated OM without PACl (0.47 L-Biogas/g-VSfed), waste activated sludge (0.35 L-Biogas/g-VSfed), and mixed sludge (0.48 L-Biogas/g-VSfed). Methane yield based on degraded VS (VSdeg) of up-concentrated OM containing PACl was 0.56 L-CH4/g-VSdeg, which was also highest. These results indicate the up-concentrated OM obtained from the DMF process has high potential for biogas production, and the addition of PACl in the DMF process (∼4.3 mg-Al/L) could enhance the biogas production.
Katsuki Kimura - One of the best experts on this subject based on the ideXlab platform.
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direct membrane filtration dmf for recovery of organic matter in municipal wastewater using small amounts of chemicals and energy
Chemosphere, 2021Co-Authors: Katsuki Kimura, Mutsumi Yamakawa, Akira HafukaAbstract:Abstract The recovery and utilization of organic matter in municipal wastewater are essential for the establishment of a sustainable society, such that these factors have drawn significant recent attention. The up-concentration of organic matter via direct membrane filtration (DMF), followed by anaerobic digestion, is advantageous over the treatment of the entire wastewater by an anaerobic process, such as an anaerobic membrane bioreactor (AnMBR). However, the occurrence of severe membrane fouling in the DMF is a problem. In this study, DMF was carried out at an existing wastewater treatment plant to attempt long-term operation. A combination of vibration of membrane modules, short-term aeration, and chemically enhanced backwash (CEB), with multiple chemicals (i.e., the alternative use of citric acid and NaClO), was found to be effective for the mitigation of membrane fouling in DMF. Furthermore, switching the feed from influents to effluents in the primary Sedimentation Basin significantly mitigated membrane fouling. In this study, in which microfiltration membrane, with a nominal pore size of 0.1 μm, was used, ∼75% of the organic matter in raw wastewater was recovered, with the volumetric concentration of wastewater by 50- or 150-fold. Organic matter recovered by DMF had significantly higher potentials for biogas production than the excess sludge generated from the same wastewater treatment plant. An analysis of the energy balance (i.e., the energy used for DMF and recovered by DMF) suggests that the proposed DMF can produce a net-positive amount of electricity of ∼0.3 kWh from 1 m3 of raw wastewater with a typical strength (chemical oxygen demand of 500 mg/L).
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anaerobic digestibility of up concentrated organic matter obtained from direct membrane filtration of municipal wastewater
Biochemical Engineering Journal, 2020Co-Authors: Akira Hafuka, Taketsugu Takahashi, Katsuki KimuraAbstract:Abstract Direct membrane filtration (DMF) process is a promising technology for up-concentration and recovery of organic matter (OM) from municipal wastewater. This study investigates anaerobic digestibility of up-concentrated OM obtained from the DMF process. Effluent from a primary Sedimentation Basin was used as feed water. Effect of polyaluminum chloride (PACl) addition to the DMF process on the anaerobic digestibility of obtained up-concentrated OM was also investigated because PACl is sometimes used as a coagulant in the DMF process for improving effluent quality and OM recovery, and for mitigating membrane fouling. Batch anaerobic digestion experiments were conducted to achieve these objectives. Fitting the obtained data to the reaction curve model revealed that maximum biogas production based on feed volatile solids (VSfed) from up-concentrated OM containing PACl reached 0.56 L-Biogas/g-VSfed, which was higher than from up-concentrated OM without PACl (0.47 L-Biogas/g-VSfed), waste activated sludge (0.35 L-Biogas/g-VSfed), and mixed sludge (0.48 L-Biogas/g-VSfed). Methane yield based on degraded VS (VSdeg) of up-concentrated OM containing PACl was 0.56 L-CH4/g-VSdeg, which was also highest. These results indicate the up-concentrated OM obtained from the DMF process has high potential for biogas production, and the addition of PACl in the DMF process (∼4.3 mg-Al/L) could enhance the biogas production.
U S Mahabaleswar - One of the best experts on this subject based on the ideXlab platform.
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large eddy simulations of particle Sedimentation in a longitudinal Sedimentation Basin of a water treatment plant part i particle settling performance
Chemical Engineering Journal, 2009Co-Authors: M Alsammarraee, Andy Chan, Salim Mohamed Salim, U S MahabaleswarAbstract:Abstract The process of particle Sedimentation in a three-dimensional longitudinal Basin in a water treatment plant is studied computationally. The fluid mixture mimics typical contaminated water in which the contaminants are represented by a spectrum of 13 different particle sizes. The processes of Sedimentation of all classes of particles are simulated. The flow patterns, the particle settling velocities, the effectiveness of the particle removal from the stream and the particle concentrations distributions along the Basin are estimated using large-eddy simulations (LES). Moreover the particles settling phenomenon and efficiency for different sizes of particles and the overall Sedimentation efficiency of the Basin are calculated. Results show that longitudinal tanks are more efficient in dealing with larger particles compared to smaller particles in terms of settling. The influent is flushed downwards to the tank bottom. The flow then creates a large recirculation eddy near the sump area. Smaller recirculation regions, which are important to Sedimentations, are also found near the entry and near the exit weir. Turbulence is generated near the inlet and outlet weir of the Basin which also tends to inhibit settling. As a result, smaller particles tend to distribute more evenly in the Basin while the larger particles settle quickly near the sump. The flow paths of the smaller particles also show that there is necessity in altering the geometries to enhance settling, especially near these turbulent regions. It also shows that there is a great deal of interactions with the Sedimentation tank geometry which has significant improvements on the design aspects of these Basins.
M Alsammarraee - One of the best experts on this subject based on the ideXlab platform.
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large eddy simulations of particle Sedimentation in a longitudinal Sedimentation Basin of a water treatment plant part i particle settling performance
Chemical Engineering Journal, 2009Co-Authors: M Alsammarraee, Andy Chan, Salim Mohamed Salim, U S MahabaleswarAbstract:Abstract The process of particle Sedimentation in a three-dimensional longitudinal Basin in a water treatment plant is studied computationally. The fluid mixture mimics typical contaminated water in which the contaminants are represented by a spectrum of 13 different particle sizes. The processes of Sedimentation of all classes of particles are simulated. The flow patterns, the particle settling velocities, the effectiveness of the particle removal from the stream and the particle concentrations distributions along the Basin are estimated using large-eddy simulations (LES). Moreover the particles settling phenomenon and efficiency for different sizes of particles and the overall Sedimentation efficiency of the Basin are calculated. Results show that longitudinal tanks are more efficient in dealing with larger particles compared to smaller particles in terms of settling. The influent is flushed downwards to the tank bottom. The flow then creates a large recirculation eddy near the sump area. Smaller recirculation regions, which are important to Sedimentations, are also found near the entry and near the exit weir. Turbulence is generated near the inlet and outlet weir of the Basin which also tends to inhibit settling. As a result, smaller particles tend to distribute more evenly in the Basin while the larger particles settle quickly near the sump. The flow paths of the smaller particles also show that there is necessity in altering the geometries to enhance settling, especially near these turbulent regions. It also shows that there is a great deal of interactions with the Sedimentation tank geometry which has significant improvements on the design aspects of these Basins.
Poborska-młynarska Katarzyna. - One of the best experts on this subject based on the ideXlab platform.
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Granica pięter cechsztynu PZ3 i PZ4 w wysadzie solnym Inowrocławia na archiwalnych fotografiach w kopalni "Solno" - przyczynek do interpretacji lokalnych warunków sedymentacji w środkowej części polskiego basenu cechsztyńskiego Zechstein PZ3/PZ4 cyclothems boundary in the Inowrocław salt dome according to archival photographs of the "Solno" mine - an interpretation of local Sedimentation conditions in the central part of the Polish Zechstein Basin /
2026Co-Authors: Poborska-młynarska Katarzyna.Abstract:Tyt. z nagłówka.Bibliogr. s. 291.Na odsłonięciach w kopalni "Solno" w Inowrocławiu (obecnie zlikwidowanej) na początku lat 80. ubiegłego wieku udokumentowano fotograficznie spękania błotne na stropie zubru brunatnego Na3t kończącego cykl sedymentacyjny piętra cechsztynu PZ3. Zuber brunatny przykryty jest warstwą soli podścielającej Na4a0, która stanowi pierwszy utwór kolejnego piętra cechsztynu PZ4. Kontakt zubru brunatnego z solą podścielającą zarysowuje się wyraziście. W niektórych odsłonięciach pojawia się na nim cienka (1-2 cm) warstewka anhydrytu, wskazująca na rozcieńczenie roztworu w zbiorniku sedymentacyjnym. Miejscami, pomiędzy spękaniami błotnymi na stropowej powierzchni zubru brunatnego a typową solą podścielającą, pojawia się cienka (decymetrowa) warstwa soli kamiennej czerwonej, ciemnoczerwonej, która prawdopodobnie powstała z rozpuszczania soli w stropowych partiach zubru. Udokumentowane fotograficznie zjawiska świadczą o krótkim epizodzie wynurzenia się dna zbiornika sedymentacyjnego i przerwania ciągłości sedymentacji na tym obszarze, a także o warunkach paleogeograficznych osadzania się soli podścielającej.Three decades ago in the exposures of the Inowrocław "Solno" salt mine, mud cracks at the top of Brown Zuber complex (Na3t) of the PZ3 Zechstein cyclothem were observed and documented in photographs. Brown Zuber complex is covered by the layer of Underlying Halite which is the first member of the PZ4 Zechstein sequence. The contact between Brown Zuber and Underlying Halite is clearly delineated. In some exposures a thin (1-2 cm) layer of anhydrite appears indicating the episode of dilution of brines in the Sedimentation Basin. Sometimes the thin (10 cm) layer of red or dark red salt occurs between the mud cracks on the top of Brown Zuber and a typical Underlying Halite. Probably the layer was created as a result of salt dissolving within the upper part of zuber and re-Sedimentation. Documented features provide the evidence of the short episode of subaerial exposure of the Basin bottom and of the discontinuities during Sedimentation in this area. They also provide new information on paleogeographic conditions of Na4a0 salt Sedimentation.Dostępny również w formie drukowanej.SŁOWA KLUCZOWE: Inowrocław, wysad solny, Cechsztyn, granica PZ3/PZ4, niedociągłość stratygraficzna, spękania błotne. KEYWORDS: Inowrocław salt dome, Zechstein, PZ3/PZ4 boundary, stratigraphic discontinuity, mud cracks