Dominating Role of Ionic Strength in the Sedimentation of Nano-TiO₂ in Aquatic Environments

Table 2

The solutions conditions of the sedimentation experiments.

Sedimentation experiment	Solution conditions
A	pH from 1.0 to 13.0
B	Ionic strength of KCl from 0.01 mM to 100 mM; Ionic strength of CaCl2 from 0.01 mM to 15 mM; pH = 7.0
C	TOC concentration of HA from 0.5 mg L^−1 to 10 mg L^−1; pH = 7.0
D	Ionic strength of mix inorganic salt solution (Na2SO4, K2SO4, MgCl2, CaCl2) from 0.5 mM to 25 mM; TOC concentration of mix NOM solution (FA, HA) from 0.5 mg L^−1 to 5 mg L^−1; pH from 6.0 to 8.0
E	Ionic strength of mix inorganic salt solution (NaCl, KCl, MgCl2, CaCl2) from 0.12 mM to 120 mM; pH = 7.0
F	Ionic strength of mix inorganic salt solution (Na2SO4, K2SO4, MgCl2, CaCl2) from 0.12 mM to 120 mM; pH from 6.0 to 8.0
G	Ionic strength of mix inorganic salt solution (Na2SO4, K2SO4, MgCl2, CaCl2) from 0.12 mM to 120 mM; TOC concentration of mix NOM solution (FA, HA) from 0.5 mg L^−1 to 5 mg L^−1; pH from 6.0 to 8.0
H	Pretreated environmental water samples