Adsorption of Anionic Surfactants onto Alumina: Characteristics, Mechanisms, and Application for Heavy Metal Removal

Table 1

The fit parameters for the SDS and STS adsorption isotherms onto γ-Al₂O₃ at different NaCl concentrations (pH 4). The maximum adsorbed amount , the equilibrium constants and for the first step and second step, respectively, and the aggregation number of hemimicelle of SDS and STS molecules.

(mM)	Surfactant	(mg/g)	(g/mg)	(g/mg)^−1
100	SDS	230	4 × 10^3	4 × 10^5	3.0
100	STS	555	3 × 10^3	4 × 10^6	3.2
10	SDS	265	4.5 × 10^3	7 × 10^5	3.0
10	STS	355	5 × 10^3	3 × 10^6	3.3
1	SDS	330	6 × 10^3	5 × 10^5	3.0
1	STS	260	3 × 10^3	4 × 10^6	3.2