Zero waste VIZ-Stal’ LLC recycling system of industrial water supply

Summary

The history of developing the first in metallurgy zero waste recycling system of industrial water supply of a transformer steel cold rolling plant at the Verkh-Isetsk steelworks (Ekaterinburg) is described. Since building the plant was planned in the centre of the city with the population of 1.5 million people on the bank of the Verkh-Isetsk pond near the drinking water intake it was required to design a system of industrial water supply with complete elimination of the wastewater and industrial wastes discharge into the environment. The first step of developing the system was retrofitting a vitriol unit for the removal of environmentally hazardous wastes – spent concentrated pickling plant liquor. Hereafter the flotation technology of oil emulsion wastewater treatment was developed. In the course of experimental studies the efficiency of using clarifiers with suspended sediment in the process of removing palm oil from recycled water of the cold rolling mill was investigated. Most attention was paid to the technical solutions of processing the wastes generated in the process of industrial wastewater treatment. The unit for oil waste incineration was designed. Wastewater sludge was initially dewatered in the filter-presses, and then dried. Designing an evaporation plant for thermal desalination of blowdown water of the closed-loop cycles of the transformer steel cold rolling plant and wastewater from the chemical treatment of the thermal power plant effluent provided for the zero discharge of the entire industrial water supply system. The experience of the Verkh-Isetsk steelworks, particularly in relation to processing solid wastes and wastewater desalination, was used in designing efficient water supply systems for various industries including the upgrade of the Novolipetsk steelworks water supply system.

Key words

wastewater , desalination , steel industry , spent pickling plant liquor , zero discharge water supply system , environment

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UDC 628.165:62-278:621.311.21

Tsabilev O. V., Strelkov A. K.

Influence of Water Acidation Degree on Quality of Permeate of a Reverse Osmosis Plant

Summary

The results of industrial tests of the plant of reverse osmosis water desalination installed in the chemical water treatment shop of the Samara hydropower station are presented. Influent water is subjected to pre-treatment in clarifiers with liming, filtering on mechanical filters and two-stage Na-cation exchange. The influence of acid doses in the course of influent water acidification and the value of permeate output on its quality is studied. The evaluation of convergence of calculated data performed with the help of specialized software with the actually received values of permeate quality is made. Оbserved dependences allow us to make adjustments of the permeate quality obtained by the calculation method.

Key words

reverse osmosis , selectivity , desalination , membrane technology

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UDC 628.165:62-278:621.311.21

Tsabilev O. V., Strelkov A. K.

Evaluation of full-scale reverse osmosis unit operational parameters

Summary

Undissolved and dissolved substances present in the water supplied to a reverse osmosis unit can form deposits. To minimize their negative effect the equipment for water pretreatment that ensures the water quality meeting the requirements set by the membrane elements manufacturers has been retrofitted into the general process flow scheme. The basic operational parameters of a full-scale reverse osmosis unit with spiral wound reverse osmosis elements are presented. Mathematical processing of the operational parameter values was carried out, the results gained were plotted. The changes in the operational parameters before and after chemical washing of the membrane elements are shown. The evaluation of the convergence of the design and actual data under the conditions considered is given. The quoted relationships allow evaluating the operational parameters of the membrane elements, determining the washing interval and efficiency of the chemical washing. The use of the presented method of evaluating the operational characteristics will also allow substantiating the warranty claims to the manufacturers of reverse osmosis units and membrane elements.

Key words

reverse osmosis , desalination , membrane technology , permeate , chemical washing , membrane element

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UDC 628.165:66.081.63

Chigaev I. G.

The use of nanofiltration in brackish water softening

Summary

The results of the experimental studies with real water are presented that showed the perspectiveness of using the purification technology based on polymer nanofiltration membranes in underground brackish water desalination as compared to reverse osmosis. The basic characteristics of nanofiltration membranes were studied. Possible concentrating of influent water by partial concentrate recycling was evaluated; the maximum salt concentrations in recycling water were determined. The studies on evaluating the effect of deposit formation on the basic membrane characteristics did not discover any noticeable permeability reduction; herewith the zones of intensive salt deposit formation on membranes were identified. It was determined that salt concentration in recycling water supplied on the membrane shall not exceed 42 mg-equ/l to obtain permeate with up to 6 mg-equ/l and for permeate with 2 mg-equ/l hardness the salt concentration shall not exceed 18 mg-equ/l. Influent water concentrating provides for the substantial reduction of discharged concentrate.

Key words

reverse osmosis , membranes , nanofiltration , desalination , underground brackish water , deposit formation

DOI 10.35776/VST.2022.02.03
UDC 628.165:66.081.6

Mazhuga Aleksandr, Kagramanov Georgii, Parusov Denis, Бланко-Педрехон А. М.

Aspects of the desalination of mineralized water in arid
and water-deficient territories

Summary

Supplying drinking water in coastal arid and water-deficient regions has been an urgent problem due to the population growth and progressive pollution of natural waters. To desalinate seawater, evaporation (distillation) or a membrane separation process – reverse osmosis – is usually used. The justification for choosing a seawater desalination method and the productivity of desalination plants is based on the solution of a number of closely related engineering, economic and environmental tasks. Water desalination involves relatively high energy costs; therefore, reducing the costs can be provided by increasing the fuel heat-availability factor, that is, by using cogeneration (cogeneration of heat and electricity). This determines the comprehensive technology of desalination using membrane methods of demineralization followed by the evaporation of the reject water. Herewith, the balance of the reverse osmosis and evaporator plant performance is determined by the ratio of the generated thermal and electrical energy.

Key words

potable water , reverse osmosis , desalination , desalination , evaporation , sea water

UDC 661.183.12
DOI 10.35776/VST.2023.08.03

Pavelkova Anna, Spitsov D. V.

Current state of the ion exchange resin market (a review)

Summary

Widespread use of ion exchange plants for both natural water and industrial wastewater treatment is driven by the use of various ion exchange resins. It provides for selecting a unit for both complete desalination of water and selective purification depending on the demands of work. The main fields of ion exchange application are considered. The specific features of ionite selection are analyzed depending on the type of filter regeneration, filtration mode and rate. The lack of a unified classification of ion exchange resins hampers their optimal choice since the very name gives no idea of their properties, which requires careful study of the characteristics. A comprehensive analysis of the current ionite market according to the classical classification, their interchangeability, possible import phaseout has been executed. The optimal choice of an ion exchange resin with the minimum cost of the treated water is made after a comprehensive analysis of the quality indicators of the treated and source water, filtration mode, type of the plant.

Key words

selectivity , desalination , water softening , ionites , cationites , anionites , chemical softening of water , demineralization