Resource efficient ferritizatio treatment for concentrated wastewater from electroplating production with aftertreatment by nanosorbents

Arhatenko

2021

This paper considers prospects for increasing the level of environmental safety of industrial enterprises as a result of the implementation of resource-saving technology of processing galvanic sludge using the ferritization method. The effectiveness of the use of electromagnetic pulse discharges for resource-saving activation of the ferritization process with the extraction of heavy metal ions from sludge (Fe, Ni, Cu, Zn) has been confirmed. The influence of key parameters of the process such as the pH value of the reaction mixture and the initial concentrations of metals in the solution on the quality of processing galvanic sludge by ferritization has been experimentally investigated. It was determined that with an increase in the pH value from 8.5 to 10.5 the residual concentrations of metal ions decrease to the values of 0.1÷0.25 mg/dm3 regardless of the total initial concentrations. It has been established that the technique of electromagnetic pulse activation ensures an adequate degree of extraction of metal ions of 99.9 %; it also has indisputable energy advantages compared to the thermal method: energy costs are reduced by more than 60 %. That indicates the suitability of purified water for reuse in galvanic production in terms of the requirements for the content of heavy metal ions in it. In addition, the structural studies of ferritization sediment samples have been carried out. The sediment is characterized by the maximum content of crystalline ferromagnetic phases of ferrite. It was established that an increase in the pH of the initial reaction mixture leads to an increase in the ferrite phase in sedimentation: at pH=10.5, phases were detected, which are characterized by a maximum ferrite content (exceeding 76 %). The proposed resource-saving ferritization process prevents environmental pollution, ensures efficient and rational utilization of raw materials and energy in the industry; it also makes it possible to obtain commodity products from industrial waste.

Section: Discussion Of Results Of Galvanic Sludge Processingmentioning

confidence: 99%

Determination of influence of pH on reaction mixture of ferritation process with electromagnetic pulse activation on the processing of galvanic sludge

Arhatenko

2021

“…At the same time, the residual concentrations of ferrum ions decrease with an increase in the aeration rate of 2.5-3.5 dm 3 /min per 1 dm 3 of the reaction mixture and have a value in the range of 0.08-0.12 mg/dm 3 . Obviously, this is due to the fact that with an increase in the amount of the oxidant leads to an intensification of the crystallization process of dispersed compounds of heavy metals [22]. The research results shown in Fig.…”

Section: Discussion Of the Results Of Processing Zinc-containing Wastewater By Ferritizationmentioning

confidence: 96%

“…But there were unresolved issues related to the study of the effect of the volumetric flow rate of air bubbling through the reaction mixture on the main parameters of the process of ferritization wastewater treatment. As a rule, during the process, a fixed flow rate of the air mixture is used -about 1 dm 3 /min [22]. However, on the basis of work [23], it can be concluded that the volume of air, and hence oxygen, bubbled through the reaction mixture, affects the processes of formation of the crystal structure of the main components of the precipitate.…”

Section: Introductionmentioning

confidence: 99%

Influence of aeration rate and method of process activation on the degree of purification of zinc-containing waste water by ferritization

Yemchura

et al. 2021

The aeration rate for the degree of purification of highly concentrated galvanic wastewater from zinc and ferrum ions was investigated using various activation methods. It is shown that the intensity of aeration has a significant effect on the quality of wastewater treatment and the characteristics of water treatment sludge. The efficiency of the use of an energy-saving method for activating the ferritization process with the use of electromagnetic pulses for the extraction of zinc ions from wastewater has been confirmed. It was determined that with an increase in the aeration rate to 3.5 dm3/min per 1 dm3 of the reaction mixture and the use of thermal activation of the process, the residual concentration of zinc ions remains within the range of 0.12÷0.2 mg/dm3. In this case, the concentration of ferrum ions decreases to values of 0.08÷0.14 mg/dm3. It was found that at an aeration rate of 2.5 dm3/min and the use of pulsed electromagnetic (EMP) activation, the residual concentrations of heavy metal ions decrease to values of 0.08÷0.16 mg/dm3. Comparison of the results indicates the advisability of using low rates of aeration of the reaction mixture. This, together with the use of resource-saving EMR process activation, allows to achieve a significant reduction in energy costs. The quantitative phase composition of ferritization precipitates was determined, in which the crystalline phases of zinc ferrite Zn2Fe2O4 and magnetite Fe3O4, as well as ferrum oxyhydroxide FeO (OH) and sodium sulfate Na2SO4, prevail. It is found that with an increase in the volumetric aeration rate, the proportion of the ferrite phase increases. At an aeration rate of 2.0 dm3/min, more than 85 % of the zinc ferrite phase was found in the sediments. Taking into account the qualitative and quantitative composition of precipitates, it is recommended to use them in the production of building materials. The experimental results obtained make it possible to provide a comprehensive processing of liquid galvanic waste.

“…One of the promising methods of such processing of etching solutions is the method of hydro-phase ferritization [15]. The essence of this method is to create conditions in spent sulfuric acid solutions that contribute to the rapid formation of dispersed chemically resistant substances with magnetic properties [16]. The course of the process of hydro-phase ferritization depends on the following technological parameters: the concentration of iron ions, the pH value, the temperature, process duration, and oxidant flow rate.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Determining the rational parameters for processing spent etching solutions by ferritization using alternating magnetic fields

Lastivka

et al. 2022

This paper reports the results of studying the application of a ferritization method for the integrated purification of used etching solutions. A feature of this work is the use of energy-saving activation of the process by alternating magnetic fields. Its advantages are shown in comparison with traditional thermal activation. The influence of magnetic induction amplitude and key technological parameters of ferritization on the quality of cleaning an etching solution has been studied. The qualitative and quantitative composition of sediments obtained after the ferritization of etching solutions was investigated. Used etching solutions are large-tonnage waste of industrial enterprises. They contain harmful pollutants that have a detrimental effect on the environment. It is promising to treat these solutions in order to obtain valuable commodity products. It is established that with an optimal value of magnetic induction amplitude of 0.1 Tl, the degree of extraction of iron ions from the solution reaches a value of 99.99 %. The best values for the main technological parameters of the process have been determined: the concentration of iron ions in the reaction mixture is 6.6 g/dm3; pH, 11.5; the duration of ferritization is 15 min. The residual concentration of iron ions in purified solutions does not exceed 0.3 mg/dm3. Thus, according to the norms of current standards, they can be reused in production. Comparative analysis indicates the advantages of electromagnetic activation of the reaction mixture. The phases of magnetite Fe3O4 and iron monohydrate δ ‒ FeOОН were detected by the method of X-ray phase analysis in ferritization sediments. It is established that with an amplitude of 0.1 Tl, the sediment contains only magnetite. The study's results indicate the possibility of further use of sediments for the manufacture of important ferromagnetic substances. The application of the improved ferritization process in production will achieve less energy consumption compared to well-known processing technologies