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Among all known inorganic pollutants of wastewater and natural water, iron compounds are the most common that adversely affect water bodies, different living organisms and human beings. Before discharging the sewage into water bodies, it is important to remove iron ions from wastewater. The application of capillary materials in water and wastewater treatment is a promising direction of ecology and technology. The capillary properties of materials allows the development of quite simple, autonomous, highly efficient and energy-saving systems for water purification. The aim of the present paper is the investigation of the influence of the basic conditions of the filtration process with the application of capillary materia on the efficiency of iron ions removal. The initial concentration of the model solution, pH and temperature of the filtration process, as well as the contact area of the liquid phase with oxygen of the air were studied. The proposed method is appropriate for the treatment of water in the concentration range from 5 to 10 mg/dm3 with an optimum pH in the range of 4–7. Experimental data showed high efficiency of capillary materials application, providing sufficient removal of iron ions from low concentrated solutions, compared to the traditional method of precipitation. The main advantage of the capillary materials is the simplicity of application of the method, quite high degree of purification and there is no need to consumpt electricity as well as additional reagents, which allows to create autonomous water treatment facilities and plants.

In this study, the optimum parameters of membrane desalinization of model solutions were determined and the required efficiency was achieved. Methods for stabilizing treatment of water before barometric desalination were developed to improve the efficiency of membranes. Methods of reagent processing of concentrates after barometric water were proposed to create a low-waste technologies for demineralization of water. It was shown that the precipitate can be used as an additive for cements and a sulfate activator for slag-portland cement.

The most promising methods of eluates recycling are electrolysis and electrodialysis. It is possible to obtain metals and purified regeneration solutions for repeated regeneration in case of application of electrochemical methods. The processes of electrolysis of solutions of cadmium and zinc sulfates and chlorides in electrolysers of different types were explored, the influence of conditions of electrolysis on effectiveness of extraction and separation of metals, obtaining inorganic acids for repeated usage in regeneration processes was determined. Single- and double-chamber electrolysers, in which cathode was made of stainless steel and titanium anode was covered with ruthenium oxide, were used. Cathodic and anodic areas in double-chamber electrolysers were separated by the anion exchange membrane MA-41. Solution of cadmium sulfate or of zinc sulfate was found in the cathodic chamber in double-chamber electrolysers. Solution of sulfuric acid with concentration of 50 mg-equiv./dm 3 was in the anodic chamber. It is recommended to carry out electrolysis for two hours when using a single-chamber electrolyser at a voltage of 5 V with the purpose of removing cadmium from sulfuric acid solution and reusing regeneration solution of sulfuric acid. Almost complete removal of cadmium ions and concentration of sulfuric acid in anolyte is achieved in case of using a double-chamber electrolyser. However, in terms of power saving, release of cadmium should be performed in single-chamber electrolysers. However, it is recommended to perform zinc removal from eluates in double-chamber electrolysers. In this case, zinc ions are almost completely removed within four hours at voltage of 25 V. The maximum current efficiency is 42‒80 %. Conditions of separation of zinc and cadmium in the eluate are associated with acidity of the solutions. A stage-by-stage removal of metals – cadmium followed by zinc, is observed during electrolysis of the mixture of cadmium and zinc chlorides in a single-chamber electrolyser. Current efficiency of metals is 30–68 %. In the case of electrolysis of a mixture of zinc and cadmium sulfates, only cadmium (В=100 %) is removed from the solution, while zinc ions completely remain in solution. Zinc is released only at the transfer of the electrolyte to a double-chamber electrolyser

The object of research is the washing waste water of galvanic plants containing heavy metal cations. The most common reagent methods for purification of galvanic drains do not provide the required degree of water purification, are accompanied by the loss of valuable components and the formation of significant amounts of toxic sludge. Ion exchange is promising in development of wastewater treatment of galvanic productions. One of the most important problems of ion-exchange technology is the processes of regeneration of ion exchangers, and, in particular, the recycling of spent regeneration solutions. The most promising in the recovery of regeneration solutions is the electrochemical method. However, electroextraction of zinc and nickel is practically impossible from acidic solutions without separation of the electrode space by the membrane. In addition, effluents from the galvanic industry contain mixtures of heavy metal ions. This complicates the process of wastewater treatment and the return of valuable components to production. In the course of the study, a strongly acidic cation exchanger KU-2-8 in the Na + -form is used to study the processes of combined sorption of heavy metal ions. Regeneration of the cation exchanger is carried out with solutions of sulfuric and hydrochloric acids. Electroextraction of zinc and nickel from acid regeneration solutions is carried out in a two-cell electrolyzer with an anion-exchange membrane MA 41. The obtained results indicate that under conditions of the concentration of heavy metals on cation exchanger KU-2-8, efficient separation can’t be achieved. It is established that ions of heavy metals are sorbed individually and in mixtures with other ions of heavy metals are effectively desorbed by solutions of sulfuric and hydrochloric acids. The use of a two-cell electrolyzer, in contrast to carrying out electrolysis processes without separation of the electrode space, almost completely eliminates zinc and nickel ions from acidic regenerative rods. And to obtain a solution of sulfuric acid in the anode chamber at a concentration of 239–651 meq/dm 3 .

Розробка ефективних засобів захисту металів від корозії в агресивних середовищах, що містять воду, нафтопродукти, карбонові кислоти та мінеральні солі, є актуальним і практично важливим завданням охорони навколишнього середовища. Для боротьби з корозією використовують інгібітори корозії, які потрібно постійно вдосконалювати та коригувати їх склад. Головним недоліком високоефективних інгібіторів на основі алкілімідазолінів, суміші алкілімідазолінів з алкілпірідінієвими та/або четвертинними амонійними сполуками розчинними в середовищі метанолу є високі ціни при відносно значних їх витратах в корозійне середовище. В роботі синтезовано інгібітори корозії сталі у нафтовмісних водних середовищах, що відповідають підвищеним еколого-економічним вимогам. Показано, що при підвищенні рівня мінералізації води відбувається зростання корозійної активності водних середовищ по відношенню до нелегованої сталі. Наявність вуглекислого газу, сірководню чи карбонових кислот призводять до підкислення водо-нафтових сумішей, внаслідок чого спостерігається підвищення швидкості корозії сталі. Досліджено ефективність синтезованих інгібіторів на основі олії та поліетиленполіамінів, які містять імідазоліни. При температурі 80 °С у суміші, що містила 200 см^3 3 % розчину хлориду натрію, 800 см^3 нафти, концентрації оцтової кислоти 0,5 та 3,0 г/дм^3 при дозі інгібітору 50 мг/дм^3 досягнуто ступеню захисту сталі від корозії на рівні 90–92 %. На основі повного факторного експерименту розраховано рівняння регресії, які дозволяють досить легко розрахувати оптимальну дозу інгібітору корозії сталі у водно-нафтових сумішах. Показано, що синтезований інгібітор перспективний при захисті металів від корозії як в мінералізованих водах, що містять нафту, так і в присутності нафтопродуктів, що містять воду It is a relevant and practically important task for environmental protection to devise effective means to protect metals against corrosion in aggressive media containing water, petroleum products, carbolic acids, and mineral salts. To stop corrosion, corrosion inhibitors are used that must be constantly improved and whose composition must be properly adjusted. The main drawback of the highly effective inhibitors based on alkyl imidazolines, a mixture of alkyl imidazolines with alkyl pyridinium and/or quaternary ammonium compounds soluble in a methanol medium, is their high prices at relatively significant consumption in the corrosive environment. This paper reports the synthesis of steel corrosion inhibitors in oil-containing aqueous environments that meet the stricter ecological and economic requirements. It has been shown that increasing the level of water mineralization improves the corrosive activity of aqueous environments relative to unalloyed steels. The presence of carbon dioxide, hydrogen sulfide, or carboxylic acids leads to the oxidation of water-oil mixtures resulting in the increased rate of steel corrosion. We have studied the effectiveness of the synthesized inhibitors based on oil and polyethylene polyamines containing imidazolines. At a temperature of 80 °C, the mixture that contained 200 cm^3 of a 3 % sodium chloride solution, 800 cm^3 of oil, and at the concentration of acetic acid of 0.5 and 3.0 g/dm^3 at the inhibitor dose of 50 mg/dm^3, has reached the degree of protection of steel against corrosion at the level of 90–92 %. Based on a full factorial experiment, the regression equation has been derived that makes it possible to easily enough calculate an optimal dose of the steel corrosion inhibitor in water-oil mixtures. It has been shown that the synthesized inhibitor shows prospects for protecting metals against corrosion both in the mineralized waters containing oil and in the presence of petroleum products containing water

Development of reliable, environmentally safe and economically advantageous methods of water purification from heavy metals is the primary task for environmental protection. The effectiveness of sorption treatment and additional treatment of natural waters from ions of heavy metals with the use of modified magnetite was studied. The samples of magnetite obtained at the ratio of concentrations of iron (II) and iron (III) of 1:2; 1:1 and 2:1 and the samples modified by sodium sulfide were used as a sorbent. Experimental studies revealed that the sorption capacity of magnetite by ions of heavy metals increases at the increase in the ratio [Fe2+]/[Fe3+] from 1:2 to 2:1. The influence of pH of the medium on the effectiveness of sorption of heavy metal ions on magnetite was studied. It was shown that the sorption capacity of magnetite for ions of copper, zinc, nickel and cadmium increases at the increase in pH of the medium from 6.0 to 8.6 due to partial hydrolysis of heavy metal ions. An increase in sorption capacity of magnetite occurs when it is modified by guanidine, thiosemicarbazide and sodium sulfide, which makes it possible to reduce residual concentrations of heavy metals to μg/dm3. The use of magnetite modified by sodium sulfite, obtained at К=2, makes it possible to completely remove cadmium ions from water and reduce copper concentration to 1.2 μg/dm3. This proves the appropriateness of using these sorbents for additional treatment or deep purification of water from ions of heavy metals. It was shown that it is appropriate to use magnetite for extraction of heavy metal ions from water in the presence of hardness ions, which do not affect the selectivity of this sorbent for ions of heavy metals. Thus, based on the obtained results of sorption purification of water from ions of heavy metals while using magnetite, we proposed a fundamental technological circuit for treatment of wastewater of nuclear power plants at discharge to water bodies

The results of research on the electrochemical processing of acidic regeneration solutions containing heavy metals ions are presented. The use of a three-cell electrolyzer makes it possible to efficiently extract zinc, copper and nickel ions from muriatic solutions and to concentrate hydrochloric acid in the cell’s intermediate chamber. The paper studies the dependence of the current yield of heavy metals on the concentration of hydrochloric acid, the initial concentration of heavy metals in the cathode chamber, the duration of electrolysis and the concentration of hydrochloric acid in its concentrating zone. The yield of copper and zinc decreases with increasing of acidity in the initial solutions and in the intermediate chamber of the cell. The current yield of nickel is determined to be little depended on the initial concentration of hydrochloric acid. The results on the concentration of hydrochloric acid, depending on the duration of electrolysis, the initial concentration of acid and heavy metals in the catholyte are presented. Bibl. 9, Fig. 9.