Adsorption Behavior of Beryllium(II) on Copper-oxide Nanoparticles Dispersed in Water: A Model for 7Be Colloid Formation in the Cooling Water for Electromagnets at High-energy Accelerator Facilities

Adsorption Behavior of Trace Beryllium (II) onto Metal Oxide Nanoparticles Dispersed in Water

“…For Al 2 O 3 , SiO 2 , TiO 2 , and Fe 2 O 3 , the slopes of the plots change between 1 and 2, indicating that n = 1 and 2. Only for CoO, the slope is between 2 and 3; this suggests that n = 2 and 3, which is the same result as for CuO (Bessho et al, 2014). As mentioned above, most of the hydroxyl groups are undissociated in the pH region where the adsorption experiments were conducted.…”

“…For all the metal oxides, the log D value increases with increasing pH. The D value at pH 6.0 varies in the order, TiO 2 ≈ SiO 2 ≈ Fe 2 O 3 > Al 2 O 3 > CuO >> CoO, where the D value for CuO is cited from the literature (Bessho et al, 2014). As an overall tendency, the D value is larger for the oxide in which the metal (including Si) has a higher valence.…”

“…All the oxides dispersed in water are 5 to 10 times greater in the average particle size than those in dry state, showing some aggregation of the nanoparticles in the solution. c. Bessho et al, 2014. In Figure 2, the zeta potentials of the five kinds of oxide nanoparticles are shown as a function of pH at a constant ionic strength of 0.01. In all cases, the zeta potential shows a continuous decrease with pH.…”

“…The log β s,n values increase with an increase in X i from CoO to Fe 2 O 3 . This result suggests that the complexation of Be 2+ with the oxide nanoparticles (Equation (2)) is governed by the deprotonation of >S−OH Bessho et al, 2014. (Equation (6)) than the bonding of >S−O − to Be 2+ (Equation (7)). A similar result was reported for the complexation of Co 2+ with metal oxides (Tamura et al, 1997) However, in the higher X i region (Fe 2 O 3 , TiO 2 , and SiO 2 ), the β s,n values of Be 2+ decrease with an increase in X i , indicating that the contribution of the coordination of >S−O − to Be 2+ exceeds that of the deprotonation of >S−OH.…”

“…In recent studies, a large part of 7 Be was found to be captured by metal-oxide colloidal nanoparticles generated through corrosion of metal components in water (Itoh et al, 1998(Itoh et al, , 1999Matsumura et al, 2009;Bessho et al, 2010;Bessho et al, 2013;Matsumura et al, 2014;Bessho et al, 2015a;Bessho, Matsumura, Takahashi, & Masumoto, 2015b). On the other hand, the adsorption behavior of trace Be 2+ onto CuO nanoparticles in water was evaluated and the complexation constants between Be 2+ and the surface hydroxyl groups of CuO were determined (Bessho, Kanaya, Shimada, Katsuta, & Monjushiro, 2014). In order to clarify the tendency and features of the interaction of Be 2+ with metal oxides, it is further necessary to determine and compare the surface complexation constants for various oxides.…”