scholarly journals Assessment of the Rheological Behavior of Polymer–Oxidant Mixtures and the Influence of the Groundwater Environment on Their Properties

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1698
Author(s):  
Qi Xu ◽  
Jiajun Chen ◽  
Xinran Song
Keyword(s):  
Xanthan Gum ◽  
Control Method ◽  
Shear Thinning ◽  
Mobility Control ◽  
Retention Rates ◽  
Viscosity Reduction ◽  
Leading Role ◽  
Salt Ions ◽  
Groundwater Environment ◽  
Water Ph

Shear-thinning polymers have been introduced to contaminant remediation in the subsurface as a mobility control method applied to mitigate the inefficient delivery of remedial agents caused by geological heterogeneity. Laboratory experiments have been conducted to assess the compatibility of polymers (xanthan and hydrolyzed polyacrylamide (HPAM)) and oxidants (KMnO4 and Na2S2O8) through quantitative evaluation of the viscosity maintenance, shear-thinning performance, and oxidant consumption. The mechanism that causes viscosity loss and the influence of the groundwater environment on the mixture viscosity were also explored. The xanthan–KMnO4 mixture exhibited the best performance in both viscosity retention and shear-thinning behavior with retention rates higher than 75% and 73.5%, respectively. Furthermore, the results indicated that xanthan gum has a high resistance to MnO4− and that K+ plays a leading role in its viscosity reduction, while HPAM is much more sensitive to MnO4−. The viscosity responses of the two polymers to Na2S2O8 and NaCl were almost consistent with that of KMnO4; salt ions displayed an instantaneous effect on the solution’s viscosity, while the oxide ions could cause the solution’s viscosity to decrease continuously with time. Since xanthan exhibited acceptable oxidant consumption as well, xanthan–KMnO4 is considered to be the optimal combination. In addition, the results implied that the effects of salt ions and the water pH on the mixture solution could be acceptable. In the 2D tank test, it was found that when xanthan gum was introduced, the sweeping efficiency of the oxidant in the low-permeability zone was increased from 28.2% to 100%. These findings demonstrated the feasibility of using a xanthan–KMnO4 mixture for actual site remediation.

Fast Upscaling of Polymer Flood Simulations Using Fractional Flow and Scaled Mobilities

2021 ◽  
Author(s):  
Hasan Al-Ibadi ◽  
Karl Stephen ◽  
Eric Mackay
Keyword(s):  
Relative Permeability ◽  
Control Method ◽  
Pressure Profile ◽  
Polymer Flooding ◽  
Mobility Control ◽  
Scale Model ◽  
Fine Scale ◽  
Fractional Flow ◽  
Water Viscosity ◽  
Flow Mobility

Abstract We introduce a pseudoisation method to upscale polymer flooding in order to capture the flow behaviour of fine scale models. This method is also designed to improve the predictability of pressure profiles during this process. This method controls the numerical dispersion of coarse grid models so that we are able to reproduce the flow behaviour of the fine scale model. To upscale polymer flooding, three levels of analysis are required such that we need to honour (a) the fractional flow solution, (b) the water and oil mobility and (c) appropriate upscaling of single phase flow. The outcome from this analysis is that a single pseudo relative permeability set that honours the modification that polymer applies to water viscosity modification without explicitly changing it. The shape of relative permeability can be chosen to honour the fractional flow solution of the fine scale using the analytical solution. This can result in a monotonic pseudo relative permeability set and we call it the Fractional-Flow method. To capture the pressure profile as well, individual relative permeability curves must be chosen appropriately for each phase to ensure the correct total mobility. For polymer flooding, changes to the water relative permeability included the changes to water viscosity implicitly thus avoiding the need for inclusion of a polymer solute. We call this type of upscaling as Fractional-Flow-Mobility control method. Numerical solution of the upscaled models, obtained using this method, were validated against fine scale models for 1D homogenous model and as well as 3D models with randomly distributed permeability for various geological realisations. The recovery factor and water cut matched the fine scale model very well. The pressure profile was reasonably predictable using the Fractional-Flow-Mobility control method. Both Fractional-Flow and Fractional-flow-Mobility control methods can be calculated in advance without running a fine scale model where the analysis is based on analytical solution even though produced a non-monotonic pseudo relative permeability curve. It simplified the polymer model so that it is much easier and faster to simulate. It offers the opportunity to quickly predict oil and water phase behaviour.

Taylor vortices in Newtonian and shear-thinning liquids

1995 ◽  
Vol 449 (1935) ◽  
pp. 155-176 ◽  
Keyword(s):  
Aqueous Solution ◽  
Axial Velocity ◽  
Xanthan Gum ◽  
Cell Structure ◽  
Outer Wall ◽  
Shear Thinning ◽  
Taylor Number ◽  
Axial Component ◽  
Vortex Cell ◽  
Newtonian Case

The flow structure in a concentric annular geometry with a radius ratio of 0.506 has been investigated for inner cylinder (centrebody) rotation. Detailed velocity measurements made with a laser Doppler anemometer for an aqueous solution of glucose (Newtonian), at a Taylor number well above the critical value, reveal that the tangential velocity component has a periodic structure of the same wavelength as that for the axial component, but with the extrema corresponding to zero axial velocity. Higher values of the maximum axial velocity and velocity gradient are observed closer to the centrebody than at the outer wall, whilst the radial location of zero axial velocity in the vortex interior (i. e. the eye of the vortex) moves towards the outer wall with increasing Taylor number. Similar measurements for an aqueous solution of Xanthan gum, which is strongly shear thinning and slightly elastic, revealed that the asymmetry in the maximum axial velocities was more marked than for the Newtonian case with a significant radial shift in the location of the vortex eye towards the centrebody. It was also found that the vortices exhibit a slow axial drift in the direction opposite to the centrebody rotation vector, whereas there was zero drift in the Newtonian case. The vortex cell structure for the second non-Newtonian fluid, a Laponite/CMC aqueous blend, which is shear thinning and also thixotropic, was very similar to that for the Xanthan gum suggesting that the shear-thinning aspect of the fluid rheology for both non-Newtonian fluids was far more significant than either thixotropy or viscoelasticity. An axial drift was again apparent, but in the opposite direction to that for the Xanthan gum, indicating that this effect is associated with the differences in the rheological characteristics of the two fluids.

scholarly journals Novel Surrogates for Membrane Fouling and the Application of Support Vector Machine in Analyzing Fouling Mechanism

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 990
Author(s):  
Xianghao Meng ◽  
Fukuan Wang ◽  
Shujuan Meng ◽  
Rui Wang ◽  
Zhongyuan Mao ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Membrane Fouling ◽  
Xanthan Gum ◽  
Quartz Crystal ◽  
Extracellular Polymeric Substances ◽  
Support Vector ◽  
Feed Water ◽  
Data Sets ◽  
Leading Role ◽  
Gel Layer

It is difficult to recognize specific fouling mechanisms due to the complexity of practical feed water, thus the current studies usually employ foulant surrogates to carry out research, such as alginate and xanthan gum. However, the representativeness of these surrogates is questionable. In this work, the classical surrogates (i.e., alginate and xanthan gum) were systematically studied, and results showed that they behaved differently during filtration. For the mixture of alginate and xanthan gum, both filtration behaviors and adsorption tests performed by quartz-crystal microbalance with dissipation monitoring (QCM-D) indicated that alginate plays a leading role in fouling development. Furthermore, by examining the filtration behaviors of extracellular polymeric substances (EPS) extracted from practical source water, it turns out that the gel layer formation is responsible for EPS fouling, and the properties of gel layer formed by EPS share more similarities with that formed from pectin instead of alginate. In addition, with the use of experimental data sets extracted from this study and our previous studies, a modeling method was established and tested by the support vector machine (SVM) to predict complex filtration behaviors. Results showed that the small differences of fouling mechanisms lying between alginate and pectin cannot be recognized by Hermia’s models, and SVM can show a discrimination as high as 76.92%. As such, SVM may be a powerful tool to predict complex filtration behaviors.

Analysis of stick-slip reduction for a new torsional vibration tool based on PID control

2019 ◽  
Vol 234 (1) ◽  
pp. 82-94 ◽  
Author(s):  
Jialin Tian ◽  
Yi Zhou ◽  
Lin Yang ◽  
Shuhui Hu
Keyword(s):  
Torsional Vibration ◽  
Pid Control ◽  
Control Method ◽  
Field Tests ◽  
Rock Breaking ◽  
Drill String ◽  
Viscosity Reduction ◽  
Stick Slip ◽  
Deep Wells ◽  
Reduction Characteristics

The phenomenon of stick-slip vibration is widespread in the exploration of deep and ultra-deep wells. It causes the reduction of the mechanical drilling rate and wastes the driving energy. Besides, it also accelerates the aging and failure of the drill strings and threatens the safety of drilling seriously. In order to effectively control the stick-slip vibration of the drill string, a new type of torsional vibration tool is proposed in this paper firstly. Then, the theoretical model of the drill string system based on the tool is established. And then, the viscosity reduction characteristics of the new torsional vibration tool are studied by the PID control method. Finally, field tests were carried out in comparison with simulation. The results show that the new torsional vibration tool can reduce the stick-slip vibration. And the two PID control equations can both control the drill bit speed in real time through changing the turntable speed. The results also have important reference significance for reducing and controlling the stick-slip vibration of the drill string and improving the rock-breaking efficiency.

Flow characteristics inside shear thinning xanthan gum non-Newtonian droplets moving in rectangular microchannels

2021 ◽  
Vol 62 (10) ◽  
Author(s):  
Mengqi Li ◽  
Zhaomiao Liu ◽  
Yan Pang ◽  
Ju Wang ◽  
Yao Lu ◽  
...  
Keyword(s):  
Xanthan Gum ◽  
Flow Characteristics ◽  
Shear Thinning ◽  
Rectangular Microchannels

scholarly journals Effects of Ionic Strength on Lateral Particle Migration in Shear-Thinning Xanthan Gum Solutions

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 535 ◽  
Author(s):  
Mira Cho ◽  
Sun Ok Hong ◽  
Seung Hak Lee ◽  
Kyu Hyun ◽  
Ju Min Kim
Keyword(s):  
Ionic Strength ◽  
Rheological Properties ◽  
Viscoelastic Fluid ◽  
Xanthan Gum ◽  
Viscoelastic Fluids ◽  
Shear Thinning ◽  
Particle Migration ◽  
Cell Counting ◽  
Contour Length ◽  
Wide Range

Viscoelastic fluids, including particulate systems, are found in various biological and industrial systems including blood flow, food, cosmetics, and electronic materials. Particles suspended in viscoelastic fluids such as polymer solutions migrate laterally, forming spatially segregated streams in pressure-driven flow. Viscoelastic particle migration was recently applied to microfluidic technologies including particle counting and sorting and the micromechanical measurement of living cells. Understanding the effects on equilibrium particle positions of rheological properties of suspending viscoelastic fluid is essential for designing microfluidic applications. It has been considered that the shear-thinning behavior of viscoelastic fluid is a critical factor in determining the equilibrium particle positions. This work presents the lateral particle migration in two different xanthan gum-based viscoelastic fluids with similar shear-thinning viscosities and the linear viscoelastic properties. The flexibility and contour length of the xanthan gum molecules were tuned by varying the ionic strength of the solvent. Particles suspended in flexible and short xanthan gum solution, dissolved at high ionic strength, migrated toward the corners in a square channel, whereas particles in the rigid and long xanthan gum solutions in deionized water migrated toward the centerline. This work suggests that the structural properties of polymer molecules play significant roles in determining the equilibrium positions in shear-thinning fluids, despite similar bulk rheological properties. The current results are expected to be used in a wide range of applications such as cell counting and sorting.

Xanthan Biopolymer Semipilot Fermentation

1981 ◽  
Vol 21 (02) ◽  
pp. 205-217 ◽  
Author(s):  
Charles J. Norton ◽  
David O. Falk ◽  
Wayne E. Luetzelschwab
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Xanthan Gum ◽  
Xanthomonas Campestris ◽  
Fermentation Broth ◽  
Nitrogen Sources ◽  
Mobility Control ◽  
Preliminary Review ◽  
Bacterial Fermentation ◽  
Culture Techniques

Abstract Using standard microbiological techniques in a semipilot plant-scalable fermenter, xanthan-specific culture techniques developed by the U.S. Dept of Agriculture's Northern Regional Research Laboratory (NRRL) were used at Marathon Oil Co.'s Denver Research Center (DRC) to obtain improved and reproducible high conversions and yields of xanthan biopolymer broth. Practical nutrients and fermenter parameters were studied to define and improve the viscosity performance and economics of xanthan broth production for thickening water in the Maraflood(TM) enhanced oil recovery process. Introduction Xanthan gum biopolymer shows promise for enhanced oil recovery. One of its current major uses is in drilling muds. After a preliminary review of its characteristics and potential for manufacture by fermentation, a scalable laboratory pilot study was conducted at DRC to evaluate the suitability of several feedstocks and bacterial organisms.Our fermentation results confirm NRRL procedures and recommendations for this bacterial fermentation and indicate a number of practical feedstocks for producing high-viscosity broths. We can reproduce xanthan broths as viscous as those previously furnished to us by NRRL and various commercial suppliers interested in this potential market for enhanced oil recovery. Initial economic estimates indicate that xanthan broths can be made for about one-half the price of commercially available biopolymer.Our research to date on the biopolymer xanthan gum and fermentation broth is summarized. This includes the chemical and physical properties, synergistic interactions, salinity effects, physical and chemical modifications, chemical and biological stabilities, mobility control properties, and oil recovery performances in cores. Experimental results indicate that broad ranges of readily available carbohydrate and nitrogen sources are suitable and economical alternative substrates for this fermentation. Dissolved oxygen concentration and oxygen usage are practical parameters for monitoring the fermentation. Experimental Carbon and nitrogen sources from several commercial suppliers were screened. Staleydex(TM) 333 dextrose (a carbon source) and Brown-Forman corndistillers dried solubles (DDS) (a nitrogen source) were selected for reproducibility studies. Enzose E-084 cornstarch hydrolysate and Argo(TM) corn steep were furnished by Corn Products Corp.Several recommended strains of Xanthomonas campestris were obtained from the American Type Culture Bank and the NRRL in Peoria, IL. The strain selected for most of our investigation was NRRL B-1459-4L. A sample of Xanthomonas manihotis from the American Type Culture Bank also was evaluated. Apparatus A Psycrotherm controlled environmental incubator shaker was used to culture cells on plates and in liquid inocula. A 14-L Microferm(TM) fermenter obtained from the New Brunswick Scientific Co. (Fig. 1) had stirring, aeration, temperature control, pressure control, foam control, and pH control. SPEJ P. 205^

A Case Study of Waterhyacinth (Eichhornia crassipes) Control in Puerto Rico Using Glyphosate and Hand Removal

2021 ◽  
pp. 1-26
Author(s):  
Wilfredo Robles ◽  
Edda L. Martínez
Keyword(s):  
Puerto Rico ◽  
Invasive Plant ◽  
Control Method ◽  
Freshwater Wetlands ◽  
Management Tool ◽  
Untreated Plot ◽  
San Jose ◽  
Neochetina Eichhorniae ◽  
Water Ph ◽  
Wildlife Refuges

Abstract Waterhyacinth is an aquatic invasive plant that is widespread in Puerto Rico where it negatively effects estuaries, freshwater wetlands, potable water reservoirs, and wildlife refuges. Specifically, the tropical estuary San Juan Bay Estuary (SJBE) has been impacted with the presence of waterhyacinth. Infestations have led to a reduction of water circulation in the system as well as facilitating the establishment of invasive fauna. Therefore, a field study was conducted in a cove between Laguna San Jose and Peninsula Cantera to assess the use of glyphosate and hand removal as a management tool for waterhyacinth control. Aquatic macroinvertebrates and water quality were also monitored as a measure of environmental impact due to management activities. Results indicated that two weeks after glyphosate application, waterhyacinth biomass was significantly reduced to 0.27 kg DW m−2 at the treated plot as compared to untreated plot that yielded 0.62 kg DW m−2. Fresh weight of waterhyacinth decreased more than 90% when hand removal was used as compared to glyphosate treatment. Dissolved oxygen and water pH were not significantly different between sites however, water salinity increased to 8-9 ppt at both plots caused by tidal activity. The order Hemiptera followed by Sarcoptiformes were common at the aquatic macroinvertebrate community. Macroinvertebrate species found associated with waterhyacinth and considered natural enemies were: Orthogalumna terebrantis, Neochetina eichhorniae, Niphograpta albiguttalis. The use of glyphosate to manage waterhyacinth at the Laguna San Jose was useful as a short-term control method and its efficacy may be enhanced over time with follow up applications in combination with hand removal.

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