Positive zeta potential

In summary, the removal of organic matter and Fe oxides significantly changes the physicochemical and surface chemical properties of soils. Thus, this pretreatment affects the overall reactivity of heavy metals in soils. The removal of organic matter and Fe oxides may either increase or decrease heavy metal adsorption. The mechanisms responsible for the changes in metal adsorption in soils with the removal of organic matter and Fe oxides include increases in pH, surface area, CEC and electrostatic attraction, decreases in the ZPC, shifts of positive zeta potentials toward... 

Incorporation of C02 in valuable products is a hot topic. Methanol has been reported to be favorably produced on Cu/Ti02 catalysts. A positive zeta potential at pH 7 was found to promote the photoactivity of C02 photoreduction [199],... 

Cement has a positive zeta potential which is diminished and eventually becomes negative on the addition of a superplasticizer [31]. 

In the virtually ignored study by Dai (with three nonself citations in five years) [521], the paper by Graham [451] is not cited either, but the key issue is both identified and clarified. Based on the results summarized in Fig. 21, the author concluded that electrostatic interaction between cationic dyes and the surface of activated carbon has a great effect on adsorption capacity. Below the isoelectric point of the activated carbon (when the positive zeta potential was above 60 mV), the capacity is significantly reduced due to electrostatic repulsion between cationic dyes and the carbon surface. In a follow-up study, while still failing to acknowledge earlier important contributions to the resolution of the key issues, Dai [522] reinforced and confirmed the electrostatic attraction vs. repulsion arguments. The author used anionic dyes (phenol red, carmine, and titan yellow) and... 

The different structure types lead to very different properties. Unlike amphibole, chrysotile fibers exhibit a positive zeta potential, which is important for its utilization as a filtration and clarifying agent in the food and drink industries as well as for the separation of viruses and pyrogens from pharmaceutical solutions. Due to the accessibility of its hollow fibers, chrysotile asbestos is unstable to acids unlike amphibole. 

In the above systems acidic dispersants give positive zeta-potentials to basic particles and basic dispersants give negative zeta-potentials to acidic particles. 

Posidyne. [Pall Cotp.] Nylon 6/6 positive zeta potential high area filter elements for microbial and particulate removal. 

The smaller the fiber diameter used in the prefilter, the greater the surface area for adsorption of particles and the better the retention of small particles. In the sixties, asbestos fibers were recognized as the best prefilter media. The individual fibrils were smaller than 0.01 ju and they had a positive zeta potential. However, when it was suspected that asbestos fibers presented a health hazard, fine diameter glass and synthetic polymer fibers were substituted. Unfortunately, neither media equals the performance of asbestos. Glass fibers are available in the finest diameters, but some users are fearful they may represent a similar health hazard. The trend has been to use polypropylene or polyester fiber prefilters. Melt blown or spun-bonded fibers are available in diameters near 1 ju. Multilayers of these media with appropriate calendering have resulted in surprisingly efficient prefilters. 

A study conducted by Pamukcu, Hannum, and Wittle (2008) demonstrated that the transport of polymer-coated dispersed nanoiron could be electrokineticaUy enhanced for subsurface remediation of tight clay soils. The polymer-coated iron nanoparticles possessed a positive zeta potential below pH 8.3 and remained... 

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