Pseudo-second order
kinetics (denoted by K22) was introduced in the middle of the 80’s
[9,10]. However it was not very popular until 1999 when Ho and McKay [11] analyzed a number of experimental results taken from
the literature, and arrived at the conclusion that, ‘‘for all of the systems
studied, [. . .] the pseudo-second order reaction kinetics provide
the best correlation of the experimental data”. After publication of
this work, K2 has become increasingly popular because, in the vast
majority of studies in which comparison has been done, superiority
of K2 over K1 has been found [12]. The original article [11] now
totalizes ca. 6000 citations, with a citation frequency that has been
increasing exponentially with time.