Influence of the presence of three typical surfactants on the adsorption of nickel (II) to aerobic activated sludge.
The effects of different surfactants (SDBS, C(14)BDMA, Tween20) on the sorption of nickel(II) onto aerobic activated sludge were studied. Results showed that the influence of surfactants on the adsorption of nickel(II) strongly depended on the type of the surfactants. The presence of SDBS enhanced nickel(II) sorption, in contrast, the presence of C(14)BDMA and Tween20 both caused a nickel(II) sorption reduction, but Tween20 had a slighter effect. With the presence of individual surfactant, the sorption kinetics and isotherms were good agreement with pseudo-second-order kinetic model and Langmuir isotherm, respectively. The surfactant impelled the nickel(II) adsorption process onto aerobic activated sludge to transform from chemisorption to physisorption, and the existence of SDBS in solution even changed the exothermic nature. From FT-IR measurements and zeta potential measurements, there was competitive relationship between C(14)BDMA and nickel(II) at the adsorption onto sludge.