The Sips isotherm equation: Often used and sometimes misused

The Sips isotherm equation, proposed in 1948, is popularly used to describe the adsorption of a diverse array water contaminants by engineered and natural adsorbents. However, that apparent popularity conceals problematic application issues. Our critique its use contaminant research threefold. First, we show linear version equation promoted several reviews bogus. We also highlight problems associated with two other versions. Second, it inappropriate compare Langmuir–Freundlich equations data correlation. Because are mathematically equivalent, they must provide exactly same fit given set data. Third, argue there little be gained applying type I isotherms, which hyperbolic curves. Such shapes can adequately interpreted simple two-parameter models such as Langmuir Freundlich equations. modeling power more profitably exploited V sigmoid