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Davide Dionisi - One of the best experts on this subject based on the ideXlab platform.
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effect of periodic feeding on substrate uptake and storage rates by a pure culture of thiothrix ct3 strain
Water Research, 2007Co-Authors: Mauro Majone, R Ramadori, Caterina Levantesi, Davide Dionisi, Mario Beccari, Valter TandoiAbstract:Abstract A pure culture of Thiothrix strain CT3 has been aerobically cultured under periodic acetate feeding in a Sequencing Batch Reactor (SBR) at volumetric organic load rate of 0.12 gCOD L −1 d −1 . Two different culture residence times (12 d or 20 d) were adopted as well as two different feed frequencies (1 and 4 d −1 , for each culture residence time), the volumetric organic load rate being the same under all conditions. The transient response of the microorganism to the periodic acetate feed was investigated through batch tests with biomass withdrawn from the SBR, as function of the different SBR operating conditions. In all tested conditions, a quick transient response to the acetate spike was Observed with fast increase of acetate uptake rate (ranging from 71 to 247 mgCOD gCOD −1 h −1 ). This transient response was mainly due to acetate storage in form of poly-hydroxybutyrate (ranging from 45% to 64% of the Observed Yield) whereas the growth response (i.e. increase of production rate of active biomass) generally played a minor role (ranging from 21% to 38% of the Observed Yield). Apart from this general trend, culture residence time as well as feed frequency had a strong impact on transient behaviour of cultured cells. The overall transient response (i.e. maximum specific substrate removal rate) increased as culture residence time decreased or as feed frequency increased. Moreover, the ratio of storage response and growth response increased as the overall transient response decreased, i.e. the storage response was preferentially maintained when cells presented a lower transient response. The ability of the cells to increase their growth rate with respect to SBR average value was the lowest under the most unfavourable conditions (residence time 20 d, feed frequency 1 d −1 ) and increased with the increase in maximum substrate uptake rate.
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effect of periodic feeding in sequencing batch reactor on substrate uptake and storage rates by a pure culture of amaricoccus kaplicensis
Water Research, 2003Co-Authors: Federico Aulenta, R Ramadori, Davide Dionisi, Mauro Majone, Antonio Parisi, Valter TandoiAbstract:A pure culture of Amaricoccus kaplicensis was aerobically cultured at a long culture residence time (YC > 12 d), under periodic acetate feeding in a sequencing batch reactor (SBR). The cycle length and, correspondingly, the volumetric organic load rate (vOLR) were varied in the range 4–24 h and 0.76–0.12 g COD l � 1 d � 1 , respectively. The transient response of the microorganism to the acetate spike was investigated throughout batch tests, as a function of SBR cycle length and vOLR. In all tested conditions, a rapid transient response was Observed, mainly due to acetate storage in the form of polyhydroxybutyrate, since growth (production of active biomass) played a minor role. Apart from this general trend, the maximum rates under transient conditions increased as the cycle length increased from 4 to 24 h. In the SBR, the longest cycle also caused a decrease in floc size and settleability as well as an increase in the Observed Yield. The Observed effect of SBR operating conditions on the physiological state of cells and their related transient response may have great significance on the performance of full scale activated sludge processes. r 2003 Elsevier Science Ltd. All rights reserved.
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sequencing batch reactor influence of periodic operation on performance of activated sludges in biological wastewater treatment
Industrial & Engineering Chemistry Research, 2001Co-Authors: Davide Dionisi, Mauro Majone, And Valter Tandoi, Mario BeccariAbstract:This paper presents the main results obtained during several years of studies with periodically fed biological reactors (sequencing batch reactors, SBRs) from the perspective of wastewater treatment. Substrate (acetate) removal mechanisms under transient conditions were studied both in the SBR and in batch tests, as were their dependence on the applied operating conditions in the SBR (organic load rate and/or sludge age, feed length, aerobic or anoxic conditions). The most general evidence was the relevant role of storage (usually representing about 70% of the overall Observed Yield) and the negligible role of growth (usually less than 10%) during acetate removal for all tested conditions. However, when acetate was present for a long enough time, physiological adaptation could occur, and the growth contribution could become more important. The applied operating conditions affected the biomass behavior. In particular, with an increase in the applied organic load rate, the Observed Yield in the SBR and the ...
Mauro Majone - One of the best experts on this subject based on the ideXlab platform.
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effect of periodic feeding on substrate uptake and storage rates by a pure culture of thiothrix ct3 strain
Water Research, 2007Co-Authors: Mauro Majone, R Ramadori, Caterina Levantesi, Davide Dionisi, Mario Beccari, Valter TandoiAbstract:Abstract A pure culture of Thiothrix strain CT3 has been aerobically cultured under periodic acetate feeding in a Sequencing Batch Reactor (SBR) at volumetric organic load rate of 0.12 gCOD L −1 d −1 . Two different culture residence times (12 d or 20 d) were adopted as well as two different feed frequencies (1 and 4 d −1 , for each culture residence time), the volumetric organic load rate being the same under all conditions. The transient response of the microorganism to the periodic acetate feed was investigated through batch tests with biomass withdrawn from the SBR, as function of the different SBR operating conditions. In all tested conditions, a quick transient response to the acetate spike was Observed with fast increase of acetate uptake rate (ranging from 71 to 247 mgCOD gCOD −1 h −1 ). This transient response was mainly due to acetate storage in form of poly-hydroxybutyrate (ranging from 45% to 64% of the Observed Yield) whereas the growth response (i.e. increase of production rate of active biomass) generally played a minor role (ranging from 21% to 38% of the Observed Yield). Apart from this general trend, culture residence time as well as feed frequency had a strong impact on transient behaviour of cultured cells. The overall transient response (i.e. maximum specific substrate removal rate) increased as culture residence time decreased or as feed frequency increased. Moreover, the ratio of storage response and growth response increased as the overall transient response decreased, i.e. the storage response was preferentially maintained when cells presented a lower transient response. The ability of the cells to increase their growth rate with respect to SBR average value was the lowest under the most unfavourable conditions (residence time 20 d, feed frequency 1 d −1 ) and increased with the increase in maximum substrate uptake rate.
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effect of periodic feeding in sequencing batch reactor on substrate uptake and storage rates by a pure culture of amaricoccus kaplicensis
Water Research, 2003Co-Authors: Federico Aulenta, R Ramadori, Davide Dionisi, Mauro Majone, Antonio Parisi, Valter TandoiAbstract:A pure culture of Amaricoccus kaplicensis was aerobically cultured at a long culture residence time (YC > 12 d), under periodic acetate feeding in a sequencing batch reactor (SBR). The cycle length and, correspondingly, the volumetric organic load rate (vOLR) were varied in the range 4–24 h and 0.76–0.12 g COD l � 1 d � 1 , respectively. The transient response of the microorganism to the acetate spike was investigated throughout batch tests, as a function of SBR cycle length and vOLR. In all tested conditions, a rapid transient response was Observed, mainly due to acetate storage in the form of polyhydroxybutyrate, since growth (production of active biomass) played a minor role. Apart from this general trend, the maximum rates under transient conditions increased as the cycle length increased from 4 to 24 h. In the SBR, the longest cycle also caused a decrease in floc size and settleability as well as an increase in the Observed Yield. The Observed effect of SBR operating conditions on the physiological state of cells and their related transient response may have great significance on the performance of full scale activated sludge processes. r 2003 Elsevier Science Ltd. All rights reserved.
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sequencing batch reactor influence of periodic operation on performance of activated sludges in biological wastewater treatment
Industrial & Engineering Chemistry Research, 2001Co-Authors: Davide Dionisi, Mauro Majone, And Valter Tandoi, Mario BeccariAbstract:This paper presents the main results obtained during several years of studies with periodically fed biological reactors (sequencing batch reactors, SBRs) from the perspective of wastewater treatment. Substrate (acetate) removal mechanisms under transient conditions were studied both in the SBR and in batch tests, as were their dependence on the applied operating conditions in the SBR (organic load rate and/or sludge age, feed length, aerobic or anoxic conditions). The most general evidence was the relevant role of storage (usually representing about 70% of the overall Observed Yield) and the negligible role of growth (usually less than 10%) during acetate removal for all tested conditions. However, when acetate was present for a long enough time, physiological adaptation could occur, and the growth contribution could become more important. The applied operating conditions affected the biomass behavior. In particular, with an increase in the applied organic load rate, the Observed Yield in the SBR and the ...
Valter Tandoi - One of the best experts on this subject based on the ideXlab platform.
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effect of periodic feeding on substrate uptake and storage rates by a pure culture of thiothrix ct3 strain
Water Research, 2007Co-Authors: Mauro Majone, R Ramadori, Caterina Levantesi, Davide Dionisi, Mario Beccari, Valter TandoiAbstract:Abstract A pure culture of Thiothrix strain CT3 has been aerobically cultured under periodic acetate feeding in a Sequencing Batch Reactor (SBR) at volumetric organic load rate of 0.12 gCOD L −1 d −1 . Two different culture residence times (12 d or 20 d) were adopted as well as two different feed frequencies (1 and 4 d −1 , for each culture residence time), the volumetric organic load rate being the same under all conditions. The transient response of the microorganism to the periodic acetate feed was investigated through batch tests with biomass withdrawn from the SBR, as function of the different SBR operating conditions. In all tested conditions, a quick transient response to the acetate spike was Observed with fast increase of acetate uptake rate (ranging from 71 to 247 mgCOD gCOD −1 h −1 ). This transient response was mainly due to acetate storage in form of poly-hydroxybutyrate (ranging from 45% to 64% of the Observed Yield) whereas the growth response (i.e. increase of production rate of active biomass) generally played a minor role (ranging from 21% to 38% of the Observed Yield). Apart from this general trend, culture residence time as well as feed frequency had a strong impact on transient behaviour of cultured cells. The overall transient response (i.e. maximum specific substrate removal rate) increased as culture residence time decreased or as feed frequency increased. Moreover, the ratio of storage response and growth response increased as the overall transient response decreased, i.e. the storage response was preferentially maintained when cells presented a lower transient response. The ability of the cells to increase their growth rate with respect to SBR average value was the lowest under the most unfavourable conditions (residence time 20 d, feed frequency 1 d −1 ) and increased with the increase in maximum substrate uptake rate.
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effect of periodic feeding in sequencing batch reactor on substrate uptake and storage rates by a pure culture of amaricoccus kaplicensis
Water Research, 2003Co-Authors: Federico Aulenta, R Ramadori, Davide Dionisi, Mauro Majone, Antonio Parisi, Valter TandoiAbstract:A pure culture of Amaricoccus kaplicensis was aerobically cultured at a long culture residence time (YC > 12 d), under periodic acetate feeding in a sequencing batch reactor (SBR). The cycle length and, correspondingly, the volumetric organic load rate (vOLR) were varied in the range 4–24 h and 0.76–0.12 g COD l � 1 d � 1 , respectively. The transient response of the microorganism to the acetate spike was investigated throughout batch tests, as a function of SBR cycle length and vOLR. In all tested conditions, a rapid transient response was Observed, mainly due to acetate storage in the form of polyhydroxybutyrate, since growth (production of active biomass) played a minor role. Apart from this general trend, the maximum rates under transient conditions increased as the cycle length increased from 4 to 24 h. In the SBR, the longest cycle also caused a decrease in floc size and settleability as well as an increase in the Observed Yield. The Observed effect of SBR operating conditions on the physiological state of cells and their related transient response may have great significance on the performance of full scale activated sludge processes. r 2003 Elsevier Science Ltd. All rights reserved.
Mario Beccari - One of the best experts on this subject based on the ideXlab platform.
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effect of periodic feeding on substrate uptake and storage rates by a pure culture of thiothrix ct3 strain
Water Research, 2007Co-Authors: Mauro Majone, R Ramadori, Caterina Levantesi, Davide Dionisi, Mario Beccari, Valter TandoiAbstract:Abstract A pure culture of Thiothrix strain CT3 has been aerobically cultured under periodic acetate feeding in a Sequencing Batch Reactor (SBR) at volumetric organic load rate of 0.12 gCOD L −1 d −1 . Two different culture residence times (12 d or 20 d) were adopted as well as two different feed frequencies (1 and 4 d −1 , for each culture residence time), the volumetric organic load rate being the same under all conditions. The transient response of the microorganism to the periodic acetate feed was investigated through batch tests with biomass withdrawn from the SBR, as function of the different SBR operating conditions. In all tested conditions, a quick transient response to the acetate spike was Observed with fast increase of acetate uptake rate (ranging from 71 to 247 mgCOD gCOD −1 h −1 ). This transient response was mainly due to acetate storage in form of poly-hydroxybutyrate (ranging from 45% to 64% of the Observed Yield) whereas the growth response (i.e. increase of production rate of active biomass) generally played a minor role (ranging from 21% to 38% of the Observed Yield). Apart from this general trend, culture residence time as well as feed frequency had a strong impact on transient behaviour of cultured cells. The overall transient response (i.e. maximum specific substrate removal rate) increased as culture residence time decreased or as feed frequency increased. Moreover, the ratio of storage response and growth response increased as the overall transient response decreased, i.e. the storage response was preferentially maintained when cells presented a lower transient response. The ability of the cells to increase their growth rate with respect to SBR average value was the lowest under the most unfavourable conditions (residence time 20 d, feed frequency 1 d −1 ) and increased with the increase in maximum substrate uptake rate.
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sequencing batch reactor influence of periodic operation on performance of activated sludges in biological wastewater treatment
Industrial & Engineering Chemistry Research, 2001Co-Authors: Davide Dionisi, Mauro Majone, And Valter Tandoi, Mario BeccariAbstract:This paper presents the main results obtained during several years of studies with periodically fed biological reactors (sequencing batch reactors, SBRs) from the perspective of wastewater treatment. Substrate (acetate) removal mechanisms under transient conditions were studied both in the SBR and in batch tests, as were their dependence on the applied operating conditions in the SBR (organic load rate and/or sludge age, feed length, aerobic or anoxic conditions). The most general evidence was the relevant role of storage (usually representing about 70% of the overall Observed Yield) and the negligible role of growth (usually less than 10%) during acetate removal for all tested conditions. However, when acetate was present for a long enough time, physiological adaptation could occur, and the growth contribution could become more important. The applied operating conditions affected the biomass behavior. In particular, with an increase in the applied organic load rate, the Observed Yield in the SBR and the ...
Jesús Colprim - One of the best experts on this subject based on the ideXlab platform.
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Minimization of sludge production by a side-stream reactor under anoxic conditions in a pilot plant.
Bioresource technology, 2012Co-Authors: Marta Coma, S Rovira, J Canals, Jesús ColprimAbstract:Abstract This study evaluates the application of an anoxic side-stream reactor in the sludge return line of a conventional activated sludge system for the reduction of biomass production. The oxidation–reduction potential was maintained at −150 mV while the applied sludge loading rate was modified by changing the percentage of return sludge treated in this reactor. The Observed Yield from the conventional system (0.513 kg VSS kg−1 COD) was continuously reduced when the portion of return sludge treated was increased. A maximum reduction of 18.3% of the Observed Yield was obtained treating the whole sludge return line. The sludge age maintained through the experiment. The organic matter removal was not deteriorated, even improved, by the proposed plant modification. Thus, simply applying an anoxic side-stream reactor would decrease the final volume of waste sludge while maintaining the sludge retention time and would, in fact, decrease the economic costs in terms of sludge handling.
