Vol 41, No 4 (2019)

The article is designated to the prospects of earthquakes prediction via monitoring of the accompanying phenomena such as conformation change of aerosols by measuring the mosaic ionization. Based on the synoptic analysis, we propose a predictive model of the recording of electric discharge processes that cause the formation of ball lightings under conditions of volumetric concentration of unlike particles of aerosols and multichannel condition of their interaction.

The forces of interaction between hydrophilic disperse particles in a humidified dispersion have been analyzed. The minimum volume fraction of water, which is acceptable for the application of DLVO theory formulas in computing the interaction between particles, was determined. It is shown that the formation of thin restricted water layers in gaps between hydrophilic particles gives rise to conditions for the attraction of the latter stipulated by the capillary forces that significantly change the properties of dispersions.

Photochemical systems are an alternative to reduce the biological and chemical contaminants persistent in hospital wastewater treatment. Although the photochemical systems are currently used in wastewater treatments, the efficiency of these systems still needs to be studied. In this work, a broadband method to evaluate the efficiency of photochemical systems: UV/H₂O₂, UV/O₃, and UV/H₂O₂/O₃, for hospital wastewater treatments is presented. The method is based on the analysis of the broadband changes in the UV-Vis absorption spectra with the real-time radiation exposure. The results presented indicate that the UV/H₂O₂/O₃ system has a higher percentage of decontaminated water and decontamination speed than the UV/H₂O₂ and UV/O₃ systems. In this regard, the proposed method provides a good alternative to evaluate the efficiency of photochemical systems used in hospital wastewater treatments.

A phosphorylated sorbent exhibiting an enhanced selectivity of Cu²⁺ sorption from aqueous media in the presence of surplus Ca²⁺ was obtained by carbonization of pine sawdust impregnated with (NH₄)₃PO₄ or a mixture of (NH₄)₃PO₄ and CO(NH₂)₂. With an increase of Ca²⁺ concentration to 1 g/dm³, the coefficient of separation using the sorbent phosphorylated in the presence of carbamide increased and reached the level of 19.6 that was three times as much as in the case of sorbent obtained without carbamide. The specific sorption capacity with respect to Cu²⁺ was higher by ~2 mg/g irrespective of the background concentration of Ca²⁺ ions; however, this capacity decreased as the content of the latter increased. The field tests of using the obtained sorbent for extraction of Ni²⁺ and Zn²⁺ at the stage of tertiary treatment of wastewater from the electroplating production facility before the wastewater discharge were carried out.

Ultrafiltration membranes were obtained by means of modification of microfiltration ceramic membranes with pyrocarbon from polyisocyanate and sodium carboxymethyl cellulose. For Ca²⁺ the retention factor and the specific productivity of the modified membranes depend on their composition and filtration time of the solution being purified and vary from 70 to 2% and from 96 to 4.7 dm³ /(m²·h) (P—1.1 MPa). The retention factor of direct scarlet dye is 99.99% at the specific productivity from 2 to 19.7 dm³/(m²·h) (P—1.2 MPa).

The results of laboratory research of processes of add-on purification of domestic and household wastewaters on units with fiber-expanded polystyrene medium of their repeated use in closed water supply system at enterprises of agroindustrial complex are given. The technological schemes of closed water-use systems of such enterprises are offered with the use of surface and ground water, whose use will enable to save material, water and energy resources while minimizing the collection of fresh water from natural water sources and protecting the environment from pollution with sewage.

The analysis of water from water distribution networks and wells has been performed for the purpose of detecting microscopic fungi, including those that are in a viable, but nonculturable state (VNCS). It was established that the application of the developed approach in the assessment of water quality allowed the microorganisms in VNCS to be detected, thereby enhancing the information content of conducted investigations.