“…In certain works, the other approaches, which cannot be related to the described above groups, were applied. Those models can be based on the empirical data (both with and without combination with conventional models) [329][330][331][332][333][334][335][336], the mass and energy balances [337][338][339][340][341], the Monte-Carlo method [342][343][344], the concentration polarization models [345][346][347] and osmotic pressure [348], the boundary layer theory [349], the dynamic modeling [350], the materials flow analysis [351], the risk and fault analysis [352][353], the numerical methods [354], the chemical kinetics and equilibrium [355], or its combinations [356]. However, such investigations were low numerous and it does not seem possible to define some of them as perspectives.…”