Surface charge and adsorption properties of chrysotile asbestos in natural waters
Changes in surface-charge adsorption properties of chrysotile asbestos aging in water were studied in a series of constant-pH laboratory experiments. Chrysotile freshly suspended in an inorganic electrolyte has a positive surface charge below pH 8.9. Charge reversal occurs within about 2 weeks due to more rapid dissolution of chrysotile's outer magnesium hydroxide surface relative to the underlying silica component of the mineral. The inorganic anions NO/sub 3//sup -/, Cl/sup -/, HCO/sub 3//sup -/, SO/sub 4//sup 2 -/ did not absorb. A constant-capacitance model can be used to relate surface charge to adsorption of protons over the pH range 7-9. At natural organic matter (NOM) concentrations at or below those encountered in natural waters, the particles can adsorb sufficient organic matter within 1 day to acquire a negative charge. Adsorption of NOM reached a maximum of 30 x 10/sup -6/ mg of C cm/sup -2/ after 21 h; catechol continued to adsorb over 5 days.
- Research Organization:
- California, Institute of Technology, Pasadena
- OSTI ID:
- 5532454
- Journal Information:
- Environ. Sci. Technol.; (United States), Vol. 19:12
- Country of Publication:
- United States
- Language:
- English
Similar Records
Natural organic-matter interactions with Cu(II) in ground water
Competitive surface complexation reactions of sulfate and natural organic carbon on soil