Determination of maintenance coefficients ofSaccharomyces cerevisiae cultures with cell recycle by cross-flow membrane filtration

The objective of the research was to evaluate in-line coagulation to improve performance during ultrafiltration (UF). In-line coagulation means use of coagulants without removal of coagulated solids prior to UF. Performance was evaluated by removal of contaminants (water quality) and by resistance to filtration and recovery of flux after hydraulic or chemical cleaning (water production). We hypothesized that coagulation conditions inappropriate for conventional treatment, in particular under-dosing conditions that produce particles that neither settle nor are removed in rapid sand filters, would be effective for in-line coagulation prior to UF. A variety of pre-treatment processes for UF have been investigated including coagulation, powdered activated carbon (PAC) or granular activated carbon (GAC), adsorption on iron oxides or other pre-formed settleable solid phases, or ozonation. Coagulation pre-treatment is often used for removal of fouling substances prior to NF or RO. It has been reported that effective conventional coagulation conditions produced larger particles and this reduced fouling during membrane filtration by reducing adsorption in membrane pores, increasing cake porosity, and increasing transport of foulants away from the membrane surface. However, aggregates produced under sweep floc conditions were more compressible than for charge neutralization conditions, resulting in compaction when the membrane filtration system was pressurized. It was known that the coagulated suspension under either charge-neutralization or sweep floc condition showed similar steady-state flux under the cross-flow microfiltration mode. Another report on the concept of critical floc size suggested that flocs need to reach a certain critical size before MF, otherwise membranes can be irreversibly clogged by the coagulant solids. The authors were motivated to study the effect of various coagulation conditions on the performance of a membrane filtration system.

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Experimental study on filtering papermaking black liquor by dynamic blade crossflow membrane

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2020-0019 ◽

2020 ◽

Vol 35 (3) ◽

pp. 464-470 ◽

Cited By ~ 2

Author(s):

Wenjie Zhao ◽

Junfei Wu ◽

Fushan Chen

Keyword(s):

Molecular Weight ◽

Experimental Study ◽

Environmental Pollution ◽

Rotational Speed ◽

Membrane Filtration ◽

Black Liquor ◽

Cross Flow ◽

Transmembrane Pressure ◽

Filtration Equipment ◽

Fundamental Reason

AbstractThe fundamental reason for the environmental pollution caused by the papermaking industry is the inadequate treatment of the black liquor. How to dispose of the lignin macromolecules, which is the main pollutants in the black liquor, is the key to addressing the environmental pollution. At present, cross-flow membrane filtration is one of the effective ways to retain and recycle lignin macromolecules in black liquor. The paper proposes the adoption of a dynamic blade cross-flow membrane filtration equipment provided by German BOKELA company to treat papermaking black liquor. The experiment shows that when the black liquor is treated with dynamic blade rotation cross-flow, the membrane with a molecular weight cut-off of nanofiltration (NP010) delivers the best retaining effect, with 28 % more lignin in black liquor than that in untreated black liquor. Meanwhile, when the blade rotational speed reaches 300 rpm and the transmembrane pressure is 0.5 or 2 bar, the flux of black liquor through nanofiltration NP010 is relatively desirable.

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Concentration and Desalination of Protein Derived from Tuna Cooking Juice by Nanofiltration

Jurnal Teknologi ◽

10.11113/jt.v65.2318 ◽

2013 ◽

Vol 65 (4) ◽

Author(s):

Muhammadameen Hajihama ◽

Wirote Youravong

Keyword(s):

Membrane Filtration ◽

Protein Concentration ◽

Protein Hydrolysate ◽

Salt Content ◽

Cross Flow ◽

Transmembrane Pressure ◽

Permeate Flux ◽

Batch Mode ◽

Additional Process ◽

Canning Industry

Tuna cooking juice is a co-product of tuna canning industry. It riches in protein, currently used for production of feed meal as well as protein hydrolysate. The finish products are usually in the form of concentrate, produced by evaporation process. However, evaporation is energy consumable process and the salt content level of the concentrate is often over the standard, thus required additional process for lowering salt content e.g. crystallization. The use of membrane technology, therefore, is of interest, since it required less energy and footprint compared with evaporation and is also able to reduce salt content of the concentrate. The aim of this study were to employ and select the membrane filtration process, and optimize the operating condition for protein concentration and desalination of tuna cooking juice. The results indicated that nanofiltration (NF) was more suitable than the ultrafiltration (UF) process, regarding the ability in protein recovery and desalination. The NF performance was evaluated in terms of permeation flux and protein and salt retentions. The protein and salt rejections of NF were 96 % and 5 %, respectively. The permeate flux(J) increased as transmembrane pressure (TMP) or cross flow rate (CFR) increased and the highest flux was obtained at TMP of 10 bar and CFR of 800 L/h. Operating with batch mode, the permeate flux was found to decrease as protein concentration increased, and at volume concentration factor about 4, the protein concentration about 10% while salt removal was aproximately 70 % of the initial value. This work clearly showed that NF was successfully employed for concentration and desalination of protein derived from tuna cooking juice.

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Comparison of suspended and fixed photocatalytic reactor systems

Water Science & Technology ◽

10.2166/wst.2001.0297 ◽

2001 ◽

Vol 44 (5) ◽

pp. 245-249 ◽

Cited By ~ 12

Author(s):

S.-U. Geissen ◽

W. Xi ◽

A. Weidemeyer ◽

A. Vogelpohl ◽

L. Bousselmi ◽

...

Keyword(s):

Membrane Filtration ◽

Cross Flow ◽

Transmembrane Pressure ◽

Specific Flow ◽

Process Step ◽

Photocatalytic Reactor ◽

Influent Concentration ◽

Film Reactor ◽

Rich Countries ◽

Optimized Conditions

Photocatalysis is a promising technology for the purification of pretreated wastewaters in sun-rich countries if an economically applicable reactor system is available. Within this project the catalyst separation as an essential process step of suspended reactor systems was investigated. For the separation of suspended catalyst a sedimentation basin with and without lamella and a membrane filtration were investigated. The sedimentation was found to be very sensitive to the kind of the ion background of wastewater, the pH, the TiO2 influent concentration as well as the hydrodynamics in the clarifier. Under optimized conditions effluent concentrations of less than 5 mg SS/L and a clear water without turbidity could be reached with a specific flow rate of up to 0.7 m3/m2/h. The best performance for P25 was achieved with a TiO2 influent concentration of 5 g/L. Membrane filtration was the only method to guarantee a complete retention of the TiO2 as well as a rejection of microorganisms and high molecular compounds. With cross-flow velocities of 3 m/s and a transmembrane pressure of 100 kPa flux rates up to 1200 L/m2/h were achieved. A flow-film-reactor (FFR) was operated with the model compound DCA under identical conditions with fixed and suspended TiO2. Whereas the fixed system has the advantage that no separation step is necessary and a simple construction can be used, suspended systems offer a three times higher reaction velocity for a catalyst concentration of 10 g/L, but are also characterized by higher investment costs.

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A New Test of Filterability for Unprocessed Wines Evaluation of the Enzyme Efficiency

Journal of Food Engineering and Technology ◽

10.32732/jfet.2021.10.2.55 ◽

2021 ◽

Vol 10 (2) ◽

pp. 55-66

Author(s):

Amélie Vallet-Courbin ◽

Soizic Lacampagne ◽

Rose Marie Canal-Llauberes ◽

Sigolène Mattalana Malzieu ◽

Tihomir Kanev ◽

...

Keyword(s):

Suspended Matter ◽

Measurement Method ◽

Membrane Filtration ◽

Enzyme Treatment ◽

Filtration Process ◽

Enzyme Efficiency ◽

Different Types ◽

Definition Of ◽

Selection Of

A new Test of Filterability has been developed. Measurements carried out with different types of wines indicate that the new filterability index is a useful tool for understanding and predicting the propensity to fouling of treated or untreated wines, e.g. with or without enzyme addition. The measurement method used in the Test of Filterability, requires only one type of membrane for all types of wine, and uses the same equipment as the traditional Fouling Index. Numerous trials have demonstrated that the filtration of wines is governed by standard blocking law. The definition of the new Test of Filterability, based on this filtration law, is proposed. The choice of membrane and the selection of the optimal pore size were based on the results of the experiments. Current methods used for the determination of fouling properties in wine filtration have been developed for the membrane filtration of small quantities of suspended matter. Enzyme treatment is a process often used in wine clarification. The new Test of Filterability indicates the best conditions for the filtration of all types of wines. The test is easy to implement and has been validated with various wines. This new Test of Filterability is an important tool for winemakers as it constitutes a simplified test of a wine's filterability. The new test may also be used to determine the filtration process that is best adapted to each wine while reducing the number of operations. The same approach may be adopted for the filtration of other liquids.

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