— We have studied the physical and chemical properties of aqueous titanium(IV) chloride solutions. The results demonstrate that, during TiCl4dissolution in water, only part of the...

The effective mineralization of nitrofurazone (10–100 mg L⁻¹) was performed in aqueous solutions in the presence of chloride ions by electrochemical treatment. The destruction of the organic pollutant molecules was due to their interaction with active oxygen- and chlorine-containing species forming at the inert anode (Pt/Ti or BDD) during electrolysis. Measurements of nitrofurazone concentration, chemical oxygen demand (COD) and total organic carbon (TOC) were used to estimate the removal efficiency of the pollutant. Both the pollutant oxidation rate and the degree of its mineralization were higher for the BDD anode due to the higher anode potentials on it in the course of electrolysis, which provides a high rate of active oxidizer species generation. As a result, practically full nitrofurazone molecule destruction (>99%) was achieved in 30 min at an anodic current density of 0.1 A cm⁻², a volume current density of 1.33 A L⁻¹ and pH 2 using BDD anodes. On the other hand, the nitrafurazone degradation efficiency was about 95% for Pt/Ti anodes under the same conditions. Additionally, byproducts of nitrofurazone electrooxidation were investigated by means of liquid chromato-mass-spectrometry (LC/MS). It was found that the initial decolorization of nitrofurazone solution, which occurs during the first 5 min of electrolysis, is due to the formation of a dichloro derivative of nitrofurazone, which causes the destruction of the π−conjugated bond system. Further electrolysis resulted in the almost complete destruction of the dichloro derivative within 30 min of electrochemical treatment.

As part of the work, studies of the quality of wastewater from alcohol production were carried out; the main characteristics were determined, such as the charge of dispersed particles and the content of organic compounds and fats. A comparison is made of the effectiveness of titanium salts, traditional aluminum, and iron-containing coagulants. It has been established that titanium salts are much more effective than traditional reagents, but their high cost significantly limits the scope of their application. The possibility of increasing the efficiency of traditional coagulants by adding various titanium salts in an amount of up to 10% of the mass has been proved. It has been established that the addition of titanium compounds to aluminum or iron-containing coagulants makes it possible to increase the cleaning efficiency by an average of 10–20% while a significant reduction in the dose of reagents is possible, which will have a positive effect on the cost of the cleaning process. It was found that the addition of titanium salts to a coagulant based on aluminum sulfate allows not only an increase in the cleaning efficiency but also further intensifies the processes of sedimentation and filtration of coagulation sludge, which will significantly reduce the size of the treatment equipment and reduce capital costs.

Titanium-containing coagulants are a new development in physical and chemical water purification processes. Despite their high efficiency and the absence of the drawbacks that are typical of traditional reagents, the high cost of titanium compounds restrains their extensive implementation. As part of this work, a concept technology for the synthesis of complex titanium-containing reagents using chemical dehydration processes was proposed. It was found that the composition of a complex titanium-containing coagulant consists of a mixture of aluminum sulfate 50–87 wt.%, aluminum chloride 10–40 wt.%, and titanium oxysulfate 2.5–10.0 wt.%. It was ascertained that the optimal content of the modifying additive in titanium compounds is 5.0–7.5 wt.%. The comparison of the coagulation efficiency of traditional aluminum- and iron-containing reagents and freshly synthesized reagents showed that the use of complex titanium-containing coagulants allows us not only to minimize the residual concentrations of various pollutants (phosphates, turbidity, oxidizable organic compounds) but also to reduce the reagent consumption by 20–25%, as well as to intensify the processes of sedimentation and filtration of coagulation sludge. Based on the data set obtained, the prospects for the production and use of complex titanium-containing coagulants for natural and wastewater of different origins are proven.

The possibility of reduction of chromium(VI) compounds by solutions of titanium(III) chloride in hydrochloric acid has been investigated. It has been shown that the considered reagent possesses...

We have studied the preparation of titanium trichloride solutions by reducing aqueous titanium tetrachloride solutions with metallic aluminum. The results demonstrate that aqueous titanium tetrachloride solutions have higher reactivity with metallic aluminum than does pure titanium tetrachloride. The highest stability is offered by solutions prepared from aqueous 25 to 40% titanium tetrachloride solutions. We have examined how the temperature and time of the reduction of aqueous titanium tetrachloride solutions influence the titanium trichloride yield and assessed the feasibility of preparing aqueous titanium trichloride solutions using aluminum waste (incineration plant slag) as a raw material. In our experiments, we have obtained combined samples of titanium trichloride solutions that can be used as catalysts or reagents in water purification processes.