Nitrate removal by immobilized cells of Phormidium uncinatum in batch culture and a continuous-flow photobioreactor

1993 ◽  
Vol 39 (6) ◽  
pp. 782-787 ◽  
Author(s):  
Jone M. Gil ◽  
Juan L. Serra
Keyword(s):  
Batch Culture ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Nitrate Removal ◽  
Phormidium Uncinatum

Design of a continuous flow immobilized-cell reactor for biosynthetical production of L-aspartic acid

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová
Keyword(s):  
Aspartic Acid ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Scale Up ◽  
Fixed Bed ◽  
Packed Bed ◽  
Fixed Bed Reactor ◽  
Experimental Program ◽  
Design Parameters ◽  
Immobilized Cell

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.

Biological denitrification in a continuous flow membrane reactor

1998 ◽  
Vol 38 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Bruce O. Mansell ◽  
Edward D. Schroeder
Keyword(s):  
System Performance ◽  
Continuous Flow ◽  
Membrane Reactor ◽  
Pore Diameter ◽  
Molecular Diffusion ◽  
Nitrate Removal ◽  
Average Pore ◽  
Membrane Area ◽  
Biological Denitrification ◽  
Approximate System

Biological denitrification in a continuous flow membrane reactor has been investigated. The nitrate-laden water treated was separated from a suspended denitrifying culture by a 0.02 μm average pore diameter membrane. Equal pressure was maintained across the membrane and nitrate was removed by molecular diffusion through the membrane and into the denitrifying culture. A nitrate removal efficiency of approximately 90% or a flux of 4 g NO3−-N/m2/d of membrane area was achieved with an influent concentration of 20 mg/L NO3−-N. A mathematical model was developed to approximate system performance. Predicted effluent concentrations for the experiments conducted were 5.7, 9.5, 11.7, and 17.6 mg/L NO3−-N. The respective measured effluent concentrations were 2.3, 6.0, 9.0, and 16.0 mg/L NO3−-N.

scholarly journals Denitrification Kinetics of Nitrate by a Heterotrophic Culture in Batch and Fixed-Biofilm Reactors

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 547
Author(s):  
Yen-Hui Lin ◽  
Yi-Jie Gu
Keyword(s):  
Continuous Flow ◽  
Nitrate Concentration ◽  
Batch Reactor ◽  
Nitrate Removal ◽  
Biofilm Reactor ◽  
Experimental Results ◽  
Heterotrophic Culture ◽  
Concentration Data ◽  
Water And Wastewater Treatment ◽  
Fixed Biofilm

Herein, the progress of nitrate removal by a heterotrophic culture in a batch reactor and continuous-flow fixed-biofilm reactor was examined. Two batch experiments for nitrate reduction with acetate degradation using 250 mL batch reactors with acclimated denitrifying biomass were conducted. The experimental results indicated that the nitrate was completely reduced; however, the acetate remained at a concentration of 280 mg/L from initial nitrate concentration of 100 mg/L. However, the acetate was fully biodegraded by the denitrifying biomass at an initial nitrate concentration of 300 mg/L. To evaluate the biokinetic parameters, the concentration data of nitrate, nitrite, acetate, and denitrifying biomass from the batch kinetic experiments were compared with those of the batch kinetic model system. A continuous-flow fixed-biofilm reactor was used to verify the kinetic biofilm model. The removal efficiency of nitrate in the fixed-biofilm reactor at the steady state was 98.4% accompanied with 90.5% acetate consumption. The experimental results agreed satisfactorily with the model predictions. The modeling and experimental approaches used in this study could be applied in the design of a pilot-scale, or full-scale, fixed-biofilm reactor for nitrate removal in water and wastewater treatment plants.

Bioethanol Production From Canola Straw Using a Continuous Flow Immobilized Cell System

2012 ◽  
Author(s):  
Anil Mathew ◽  
Mitch Crook ◽  
Keith Chaney ◽  
Andrea Humphries
Keyword(s):  
Continuous Flow ◽  
Immobilized Cells ◽  
Continuous Fermentation ◽  
Energy Generation ◽  
Volumetric Productivity ◽  
Production Costs ◽  
Biodiesel Production ◽  
Bioethanol Production ◽  
Capital Costs ◽  
Canola Straw

Global cultivation of canola increased by approximately 22% between 2000 and 2009, due to increased demand for canola oil for biodiesel production and as an edible oil. In 2009 over 290,000 km2 of canola was cultivated globally. In contrast to oilseed, the commercial market for canola straw is minimal and it is generally ploughed back into the field. The high carbohydrate content (greater than 50 % by dry weight) of canola straw suggests it would be a good feedstock for second-generation bioethanol production. There are four major steps involved in bioethanol production from lignocellulosic materials: (i) pretreatment, (ii) hydrolysis, (iii) fermentation, and (iv) further purification to fuel grade bioethanol through distillation and dehydration. Previous research demonstrated a glucose yield of (440.6 ± 14.9) g kg−1 when canola straw was treated using alkaline pretreatment followed by enzymatic hydrolysis. Whilst bioethanol can be produced using cells free in solution, cell immobilization provides the opportunity to reduce bioethanol production costs by minimizing the extent to which down-stream processing is required, and increasing cellular stability against shear forces. Furthermore, the immobilization process can reduce substrate and product inhibition, which enhances the yield and volumetric productivity of bioethanol production during fermentation, improves operational stability and increases cell viability ensuring cells can be used for several cycles of operation. Previous research used cells of Saccharomyces cerevisiae immobilized in Lentikat® discs to convert glucose extracted from canola straw to bioethanol. In batch mode a yield of (165.1 ± 0.1) g bioethanol kg−1 canola straw was achieved. Continuous fermentation is advantageous in comparison to batch fermentation. The amount of unproductive time (e.g. due to filling, emptying and cleaning) is reduced leading to increased volumetric productivity. The higher volumetric productivity of continuous fermentation means that smaller reactor vessels can be used to produce the same amount of product. This reduces the capital costs associated with a fermentation plant. Research demonstrated a higher bioethanol yield was attained (224.7 g bioethanol kg−1 canola straw) when glucose was converted to bioethanol using immobilized cells in packed-bed continuous flow columns. On an energy generation basis, conversion of 1 kg of canola straw to bioethanol resulted in an energy generation of 6 MJ, representing approximately 35% energy recovery from canola straw. The amount of energy recovered from canola straw could be improved by increasing the amount of energy recovered as bioethanol and by utilising the process by-products in a biorefinery concept.

scholarly journals Phenol Degradation Kinetics by Free and Immobilized Pseudomonas putida BCRC 14365 in Batch and Continuous-Flow Bioreactors

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 721
Author(s):  
Yen-Hui Lin ◽  
Yu-Siang Cheng
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Pseudomonas Putida ◽  
Growth Phase ◽  
Continuous Flow ◽  
Specific Growth ◽  
Immobilized Cells ◽  
Phenol Degradation ◽  
Exponential Growth Phase ◽  
Steady State Condition

Phenol degradation by Pseudomonas putida BCRC 14365 was investigated at 30 °C and a pH of 5.0–9.0 in the batch tests. Experimental results for both free and immobilized cells demonstrated that a maximum phenol degradation rate occurred at an initial pH of 7. The peak value of phenol degradation rates by the free and immobilized cells were 2.84 and 2.64 mg/L-h, respectively. Considering the culture at 20 °C, there was a lag period of approximately 44 h prior to the start of the phenol degradation for both free and immobilized cells. At the temperatures ranging from 25 to 40 °C, the immobilized cells had a higher rate of phenol degradation compared to the free cells. Moreover, the removal efficiencies of phenol degradation at the final stage were 59.3–92% and 87.5–92%, for the free and immobilized cells, respectively. The optimal temperature was 30 °C for free and immobilized cells. In the batch experiments with various initial phenol concentrations of 68.3–563.4 mg/L, the lag phase was practically negligible, and a logarithmic growth phase of a particular duration was observed from the beginning of the culture. The specific growth rate (μ) in the exponential growth phase was 0.085–0.192 h−1 at various initial phenol concentrations between 68.3 and 563.4 mg/L. Comparing experimental data with the Haldane kinetics, the biokinetic parameters, namely, maximum specific growth rate (μmax), the phenol half-saturation constant (Ks) and the phenol inhibition constant (KI), were determined to equal 0.31 h−1, 26.2 mg/L and 255.0 mg/L, respectively. The growth yield and decay coefficient of P. putida cells were 0.592 ± 4.995 × 10−3 mg cell/mg phenol and 5.70 × 10−2 ± 1.122 × 10−3 day−1, respectively. A completely mixed and continuous-flow bioreactor with immobilized cells was set up to conduct the verification of the kinetic model system. The removal efficiency for phenol in the continuous-flow bioreactor was approximately 97.7% at a steady-state condition. The experimental and simulated methodology used in this work can be applied, in the design of an immobilized cell process, by various industries for phenol-containing wastewater treatment.

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