The main problem of widespread introduction of magnetic water treatment (MWT) in the processes of water and wastewater treatment is the lack of modern research aimed at studying the mechanisms of MWT effects, in particular the influence on the physicochemical properties of aqueous solutions. This study explain the effect of MWT taking into account the physical and chemical properties of aqueous solutions due to the presence of quantum differences in water molecules. All of the MWT effects are related to the change in the physicochemical properties of aqueous solutions. It is due to the presence of two types of water molecule isomers and their librational oscillations. The result of MWT is a violation of the synchronism of para-isomers vibrations, with the subsequent destruction of ice-like structures due to the receiving of energy from collisions with other water molecules (ortho-isomers). One of the most important MWT effects are the change in the nature and speed of the physicochemical processes in aqueous solutions by increasing the number of more physically and chemically active ortho-isomers. The MWT parameters specified in the work allow to explain the nature of most MWT effects and require to develop scientific and methodological principles for the implementation of the MWT process and mathematical modeling of the MWT process in water and wastewater treatment. It can be use on the design of MWT devices taking into account constructive and mode parameters of MWT devices.