The effects of physical treatment on physicochemical and biological properties of water and aqueous solutions

Abstract

Objectives. Changes to the properties of water caused by factors such as pressure or temperature, can only be explained by its structural changes. Scientists study changes to the properties of water due to various physical stimuli only without the addition of any substances. Examples of stimuli are acoustic exposure, thermal exposure, pressure variation, shaking, intensive vibration treatment followed by dilutions, vortexing, bubble generation, inter alia.The aim of the present review article is to summarize the available data on how the above processes affect the physicochemical and biological properties of water and aqueous solutions.Results. It has been shown that heating makes water less compressible and decreases air solubility in water, while cooling enhances its viscosity. Acoustic exposure makes the structure of water become coarse-grained, followed by an increase the number of large clusters, pH and temperature inside a cavitation bubble. High pressure enhances the viscosity, self-diffusion, and compressibility of water. For bubble processed water, there are changes in the spin-spin and spin-lattice relaxation times. Reactive oxygen species are formed, as well as increased solubility of gases in liquids and reduced friction. Vortex process technology causes an increase of electrical conductivity of water and reduced viscosity. Intensive vibration treatment and dilution processes result in changes in electrical conductivity of water, dissolved gas concentration, ultrasonic wave velocity, рН, surface tension, dielectric constant, and spectral response. There is also data to support the biological effects of different types of physical treatment of solutions.Conclusions. This review shows that physical treatment of water can induce changes both in physicochemical and biological properties of water and aqueous solutions.