A comparative investigation was conducted into the operation of two descriptions of reverse osmosis. One of them was based on the equations of the Kedem-Katchalsky (KK) formalism, and the other on the reduced transport equations of the Kargols mechanistic formalism. It was demonstrated that if the former makes use of the correlation between KK transport parameters, i.e., the relation given by the formula omega = (I - sigma(2)) (c) over bar (s) L-p, the description becomes identical with the latter, as well as consistent with the expectation. This situation testifies to the fact that transport equations of both formalisms are mutually equivalent.