The Influence of the Magnetic Field on the Zeta Potential of Precipitated Calcium Carbonate

Stražišar, J.; Knez, Sergej; Kobe, Spomenka

doi:10.1002/1521-4117(200112)18:5/6<278::aid-ppsc278>3.0.co;2-9

Cited by 7 publications

(4 citation statements)

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“…The gradual collapse of ζ-potential and its increase to +20 mV after 10 min in hard waters when the temperature has increased to 40 °C suggests that the sheathed nanobubbles become unstable, tending to coagulate and disperse or collapse, leaving behind extended particles of amorphous calcium carbonate, the precursor of aragonite. The positive ζ-potential coincident with the onset of precipitation of aragonite is consistent with previous work, although the ζ-potential of well-crystallized calcium carbonate is usually negative. , …”

Section: Discussionsupporting

confidence: 91%

Interaction and Stability of Nanobubbles and Prenucleation Calcium Clusters during Ultrasonic Treatment of Hard Water

Fitzgerald,

Kumar,

Poulose

et al. 2024

ACS Omega

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To investigate the stability of nanobubbles in natural hard water, a series of eight samples ranging in hardness from 0 to 332 mg/L CaCO 3 were sonicated for periods of 5−45 min with an ultrasonic horn. Conductivity, temperature, ζ-potential, composition, and pH of the water were analyzed, together with the crystal structure of any calcium carbonate precipitate. Quasistable populations of bulk nanobubbles in Millipore and soft water are characterized by a ζ-potential of −35 to −20 mV, decaying over 60 h or more. After sonicating the hardest waters for about 10 min, they turn cloudy due to precipitation of amorphous calcium carbonate when the water temperature reaches 40 °C; the ζ-potential then jumps from −10 to +20 mV and remains positive for several days. From an analysis of the change of conductivity of the hard water before and after sonication, it is estimated that 37 ± 5% of calcium was not originally in solution but existed in nanoscale prenucleation clusters, which decorate the nanobubbles formed in the early stages of sonication. Heating and charge screening in the nanobubble colloid cause the decorated bubbles to collapse or disperse, leaving an amorphous precursor of aragonite. Sonicating the soft supernatant increases its conductivity and pH and restores the negative ζ-potential associated with bulk nanobubbles, but there is no further precipitation. Our study of the correlation between nanobubble production and calcium agglomeration spanning the hardness and composition ranges of natural waters shows that the sonication method for introducing nanobubbles is viable only for hard water if it is kept cold; the stability of the nanobubble colloid will be reduced in any case by the presence of dissolved calcium and magnesium.

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Section: Discussionsupporting

confidence: 91%

Interaction and Stability of Nanobubbles and Prenucleation Calcium Clusters during Ultrasonic Treatment of Hard Water

Fitzgerald,

Kumar,

Poulose

et al. 2024

ACS Omega

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“…water and growth media. It is well established that magnetic fields affect various physical properties of solutes, such as formation of calcium carbonate (Strazisar et al 2001), water vaporisation , ion hydration and resin absorption (Baran and Degtyarev 2001). Usually, these effects are achieved with very strong magnetic fields in the milliTesla to Tesla range; for that reason these results may be pertinent for experiments done at high magnetic flux densities.…”

Section: Magnetic Effects On Solutesmentioning

confidence: 99%

Magnetoreception in plants

2005

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This article reviews phenomena of magnetoreception in plants and provides a survey of the relevant literature over the past 80 years. Plants react in a multitude of ways to geomagnetic fields-strong continuous fields as well as alternating magnetic fields. In the past, physiological investigations were pursued in a somewhat unsystematic manner and no biological advantage of any magnetoresponse is immediately obvious. As a result, most studies remain largely on a phenomenological level and are in general characterised by a lack of mechanistic insight, despite the fact that physics provides several theories that serve as paradigms for magnetoreception. Beside ferrimagnetism, which is well proved for bacterial magnetotaxis and for some cases of animal navigation, two further mechanisms for magnetoreception are currently receiving major attention: (1) the "radical-pair mechanism" consisting of the modulation of singlet-triplet interconversion rates of a radical pair by weak magnetic fields, and (2) the "ion cyclotron resonance" mechanism. The latter mechanism centres around the fact that ions should circulate in a plane perpendicular to an external magnetic field with their Lamor frequencies, which can interfere with an alternating electromagnetic field. Both mechanisms provide a theoretical framework for future model-guided investigations in the realm of plant magnetoreception.

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“…1 was based on operating conditions for proper magnetic water treatment suggested by Strazisar et al (2001): the fluid flow was orthogonal with respect to magnetic field direction; magnetic field strength was at least 0.5-1 Tesla; there was a long residence time; and the water flow was in turbulent region.…”

Section: Mft System Developmentmentioning

confidence: 99%

“…Common chemical methods used to reduce water scaling, including the addition of lime or ion exchange systems, are not costeffective, change the water chemistry, and can even cause harmful health effects. Therefore, researchers viewed MFT as a potential alternative to these methods because MFT is a physical treatment that should not alter the water chemistry and is more cost-effective because of low maintenance and low capital investment to install MFT systems (Lipus and Dobersek, 2007) Reported claims for exposing water to a magnetic field include lower scale formation rate, development of soft scale formations, change in size of precipitated particles, and no significant effects (Strazisar et al 2001). Regardless of varied results from MFT studies and a lack of a proven mechanism to describe how MFT alters water chemistry, MFT has the potential to be a useful physical treatment for the removal of minerals (Busch and Busch 1997).…”

Section: Introductionmentioning

confidence: 99%

Value Addition of Greek Yogurt Whey Using Magnetic Fluid and Sepiolite Treatments

Kyle

Amamcharla

2015

Food Bioprocess Technol

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Magnetic fluid treatment (MFT) and the addition of a magnesium hydrosilicate clay mineral, sepiolite, were evaluated as physical cost-effective methods to add value to Greek yogurt whey (GYW), a co-product of Greek yogurt manufacturing. Three separate batches of GYW were obtained from two US Greek yogurt manufacturers. A GYW sample was collected from each batch, adjusted to a pH of 7.2, and recirculated for 5 min through a pumping system at a rate of 7.5 L/min with or without exposure to a 0.6 Tesla permanent magnetic field. The sample was split into thirds, heated to 80°C, and then sepiolite was added at one of three levels: 0, 2, or 4 g of sepiolite per 100 g GYW. After centrifugation at 1000g for 5 min, samples formed a top aqueous and a bottom sediment layer. Top aqueous layers were analyzed for total solids, ash, lactose, protein, calcium, phosphates, and sodium contents along with color. MFT did not feasibly affect the analyzed GYW components from both manufacturers. Protein within the top aqueous layers compared to GYW significantly decreased about 60 % for manufacturer 1 and 45 % for manufacturer 2 with either amount of sepiolite treatment. The color values b* and a* in the GYW from both manufacturers significantly decreased with the addition of sepiolite by about 70 and 90 %, respectively. MFT in the present study was not a practical treatment method for de-mineralizing GYW. However, sepiolite was found to have possible applications in the removal of proteins, phosphates, and natural color pigments in GYW.

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The Influence of the Magnetic Field on the Zeta Potential of Precipitated Calcium Carbonate

Cited by 7 publications

References 0 publications

Interaction and Stability of Nanobubbles and Prenucleation Calcium Clusters during Ultrasonic Treatment of Hard Water

Interaction and Stability of Nanobubbles and Prenucleation Calcium Clusters during Ultrasonic Treatment of Hard Water

Magnetoreception in plants

Value Addition of Greek Yogurt Whey Using Magnetic Fluid and Sepiolite Treatments

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