Kinetic enzymatic resolution in scCO2 – Design of continuous reactor based on batch experiments

2013 ◽  
Vol 79 ◽  
pp. 127-132 ◽  
Author(s):  
E. Székely ◽  
M. Utczás ◽  
B. Simándi
Keyword(s):  
Continuous Reactor ◽  
Batch Experiments ◽  
Enzymatic Resolution

Enzymatic resolution of racemic amines in a continuous reactor in organic solvents

1992 ◽  
Vol 40 (7) ◽  
pp. 760-767 ◽  
Author(s):  
Arie L. Gutman ◽  
Elazar Meyer ◽  
Evgeny Kalerin ◽  
Felix Polyak ◽  
Jeffrey Sterling
Keyword(s):  
Organic Solvents ◽  
Continuous Reactor ◽  
Enzymatic Resolution ◽  
Racemic Amines

Enzymatic resolution of (S)-(+)-naproxen in a continuous reactor

1991 ◽  
Vol 38 (6) ◽  
pp. 659-664 ◽  
Author(s):  
Ezio Battistel ◽  
Daniele Bianchi ◽  
Pietro Cesti ◽  
Carlo Pina
Keyword(s):  
Continuous Reactor ◽  
Enzymatic Resolution

Production of Nitrous Oxide Gas during Denitrification of Wastewater

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1027-1036 ◽  
Author(s):  
K. Hanaki ◽  
Z. Hong ◽  
T. Matsuo
Keyword(s):  
Nitrous Oxide ◽  
Low Ph ◽  
Continuous Reactor ◽  
Batch Experiments ◽  
Solid Retention Time ◽  
N2o Production ◽  
Flow Reactors ◽  
Nitrite Removal ◽  
Nitrate And Nitrite ◽  
Favorable Conditions

Laboratory-scale experiments were conducted to examine nitrous oxide (N2O) production during denitrification. Substrate containing acetate (909 mgl-1 as COD), yeast extract (91 mgl-1 as COD) and KNO3 with COD/NO3-N of 1.5, 2.5, 3.5 and 4.5 was continuously fed to 3 l mixed flow reactors with varied solid retention time (SRT). N2O in produced nitrogenous gas far exceeded 10% in some conditions, and up to 8% of influent NO3-N was transformed to N2O. Low COD/NO3-N, short SRT and low pH were favored conditions for N2O production. COD/NO3-N of 1.5 and 2.5 at an SRT shorter than 10 days, and COD/NO3-N of 3.5 or 4.5 at an SRT shorter than 1 day resulted in N2O production together with incomplete nitrate and nitrite removal. Lower COD/NO3-N caused higher production of N2O. N2O production at pH of 6.5 was significantly higher than that at pH of 7.5 although pH of 7.5 and 8.5 showed less difference. The mixed liquor from the continuous reactor producing N2O readily produced N2O even when substrate with high COD/NO3-N was dosed in batch experiments, which suggests that N2O producing species may be accumulated during continuous operation in favorable conditions.

Simultaneous removal of nitrate and atrazine from groundwater

2000 ◽  
Vol 41 (4-5) ◽  
pp. 49-56 ◽  
Author(s):  
I. Katz ◽  
C. Dosoretz ◽  
Y. Ruskol ◽  
M. Green
Keyword(s):  
Continuous Reactor ◽  
Fluidized Bed Reactors ◽  
Second Phase ◽  
Simultaneous Removal ◽  
Batch Experiments ◽  
Operational Conditions ◽  
Biological Removal ◽  
A Value ◽  
Degradation Activity ◽  
Atrazine Degradation

The objective of this research was to study the simultaneous removal of atrazine and nitrate by Pseudomonas ADP in a continuous reactor. Results obtained from batch experiments demonstrated that P. ADP kept the ability to degrade and mineralize atrazine under both aerobic and anoxic conditions. Results from fluidized bed reactors with P. ADP proved efficient biological removal of both nitrate and atrazine. Atrazine degradation in all the reactors studied and under all operational conditions followed the same pattern: First phase, which lasted for 3–5 weeks, with atrazine degradation of about 95% conversion, followed by a second phase where atrazine degradation efficiency decreased gradually, reaching a value of between 10–25%. Results from sterile and non-sterile chemostats experiments indicated that the reason for the decrease in atrazine degradation activity in the continuous reactors was due to the penetration of foreign denitrifying bacteria which did not have the ability to degrade atrazine.

IDENTIFYING ANAEROBIC DIGESTION MODELS USING SIMULTANEOUS BATCH EXPERIMENTS

2010 ◽  
Vol 9 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Xavier Flotats ◽  
Jordi Palatsi ◽  
Belen Fernandez ◽  
M. Angels Colomer ◽  
Josep Illa
Keyword(s):  
Anaerobic Digestion ◽  
Batch Experiments

Behaviour of Mechanically Blended Return-Sludge in Absence of Substrate

1970 ◽  
Vol 5 (1) ◽  
pp. 34-54
Author(s):  
Shyam D. Bokil ◽  
Jatinder K. Bewtra
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Aeration Rate ◽  
Batch Experiments ◽  
Sludge Treatment ◽  
Waring Blender ◽  
Settling Characteristics

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge

An equation for the empirical design of anoxic zones used to eliminate rising sludges at nitrifying activated sludge plants

1996 ◽  
Vol 33 (3) ◽  
pp. 185-194 ◽  
Author(s):  
M. Sarioglu ◽  
N. Horan
Keyword(s):  
Activated Sludge ◽  
Empirical Equation ◽  
Nitrate Nitrogen ◽  
Critical Concentration ◽  
Settling Tank ◽  
Limited Information ◽  
Batch Experiments ◽  
Anoxic Zone ◽  
Secondary Settling ◽  
Anoxic Zones

Anoxic zones are designed for the removal of nitrogen in nitrifying activated sludge plants. This can be carried out either to achieve a nitrogen discharge consent or to eliminate the problem of rising sludges. The rising sludge problem is mostly encountered in medium and small size plants in warm conditions and there is limited information as to the appropriate design of anoxic zones to protect against rising sludges in the secondary sedimentation tanks. Therefore a series of batch experiments were undertaken in order to establish the critical concentration of nitrate-nitrogen which causes rising sludge in the secondary settling tank and the effect of environmental factors such as temperature (15°C to 30°C) and residual carbon source (100 to 600 mg/1 COD) were examined. Based on the results of these experiments an empirical equation was presented which can be used to size an anoxic zone to eliminate rising sludges. The application of this equation at full-scale plants is discussed.

Surface charge and extracellular polymer of sludge in the anaerobic degradation process

1996 ◽  
Vol 34 (5-6) ◽  
pp. 309-316 ◽  
Author(s):  
X. S. Jia ◽  
Herbert H. P. Fang ◽  
H. Furumai
Keyword(s):  
Surface Charge ◽  
Growth Phase ◽  
Anaerobic Degradation ◽  
Degradation Process ◽  
Anaerobic Sludge ◽  
Batch Experiments ◽  
High Substrate Concentration ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Extracellular Polymer

Changes of surface charge and extracellular polymer (ECP) content were investigated in batch experiments for three anaerobic sludges, each of which had been enriched at 35°C and pH 639-7.3 for more than 40 batches using propionate, butyrate and glucose, individually, as the sole substrate. Results showed that both ECP and the negative surface charge were dependent on the growth phase of microorganisms. They increased at the beginning of all batches when the microorganisms were in the prolific-growth phase, having high substrate concentration and food-to-microorganisms ratio. Both later gradually returned to their initial levels when the microorganisms were in the declined-growth phase, as the substrate became depleted. The negative surface charge increased linearly with the total-ECP content in all series with slopes of 0.0187, 0.0212 and 0.0157 meq/mg-total-ECP for sludge degrading propionate, butyrate and glucose, respectively. The change of surface charge for the first two sludges was mainly due to the increase of proteinaceous fraction of ECP; but, for glucose-degrading sludge, that could be due to the increases of both proteinaceous and carbohydrate fractions of ECP. The negative-charged nature of anaerobic sludge implies that cations should be able to promote granulation of anaerobic sludge.

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