Wyniki wyszukiwania - BazTech

1

Application of Low-Pressure Reverse Osmosis Membranes for Drinking Water Softening

Gomelya Mykola, Shabliy Tetyana, Radovenchyk Iaroslav, Vakulenko Anna

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 5

154--162

EN

The processes of water purification with increasing selection of permeate were studied, considering selectivity and productivity of membranes, dynamics of changes of contents of components in the concentrate. It is shown that when chlorides and sulfates are removed from water, the increase in their content in the concentrate does not differ practically from the measured and calculated values. At the same time, the nature of dependences on the change in hardness, concentration of calcium and magnesium ions, alkalinity obtained experimentally differ significantly from the dependences obtained by theoretical calculations at permeate selection levels of > 70%. А significant difference in the determined and calculated concentrations of hardness ions in the concentrates was observed after hardness values greater than 30–40 mg-eq/dm3. This indicates the partial removal of hardness ions and carbonates from the concentrates, which may be the reason for the formation of deposits on the membrane. Permissible values of the degree of permeate selection were determined, at which there is no intense deposition of carbonates and hydroxides of hardness ions on the membrane. With the initial water hardness > 8 mg-eq/dm3, the degree of permeate selection could reach 60–70% without the risk of sedimentation on the membrane. Effectiveness of the low-pressure reverse osmosis membrane in the purification of mine water with an increased level of mineralization and hardness was determined. A significant difference between the determined and calculated hardness in concentration was observed already at the degree of permeate selection of 22–33%.

2

Low waste technology for the removal of nitrates from water

Trus Inna, Gomelya Mukola, Halysh Vita, Tverdokhlib Mariia, Makarenko Iryna, Pylypenko Tetiana, Chuprinov Yevhen, Benatov Daniel, Zaitsev Hennadii

Archives of Environmental Protection

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2023

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Vol. 49, no 1

74--78

EN

As a rule, nitrates are present in all natural water bodies. Their increased concentrations are connected with the discharge of insufficiently treated wastewater from industrial and communal enterprises, agricultural and livestock complexes. Recent scientific publications concerning treatment methods for nitrates removal from natural water and wastewater were analyzed in order to create effective and low-waste technology for obtaining high quality water. It has been established that the ion exchange method is quite effective for removing nitrates from water. In the paper, the processes of ion exchange removal of nitrates from water on low-axis anionite in DOWEX Marathon WBA in Сl- form were investigated. During the sorption of nitrates with a concentration of 186, 205, 223 and 2200 mg/dm3, it was established that the full exchangeable dynamic capacity was 1.075, 1.103, and 1.195, 1.698 g-eq/dm3, respectively. To regenerate anionite, solutions of ammonia as well as potassium chloride, ammonium chloride and potassium carbonate were used in this work. The choice of potassium and ammonium compounds is due to the prospect of further use of regeneration solutions for the production of liquid fertilizers.

3

Efficiency of Reverse Osmosis and Ion Exchange in Water Purification from Nitrates

Gomelya Mykola, Shabliy Tetyana, Makarenko Iryna, Vakulenko Anna

Journal of Ecological Engineering

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2022

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Vol. 23, nr 10

172--180

EN

The process of extracting nitrates from water by the methods of reverse osmosis and ion exchange was investigated in the paper. In the formation of reverse osmosis, low-pressure membranes were used, and in ion-exchange processes, highly alkaline anionite AB–17–8 was applied in salt form. The dynamics of changes in the concentration of nitrates in the permeate and the concentration with an increase in the degree of permeate selection from 9 to 90% at initial nitrate concentrations of 18, 50 and 100 mg/dm3 were determined. The indicators of selectivity and productivity of membranes were calculated depending on the degree of permeate selection. It was shown that the low-pressure reverse osmosis membrane is characterized by low selectivity values at high productivity values in the selected part of the nitrate concentration. It was established that the ion exchange method is significantly more effective than reverse osmosis in removing nitrates from water. It ensures the reduction of nitrate content in purified water to a value of less than 1 mg/dm3 when the degree of their extraction is reached at the level of 99%. As the ionite is saturated with nitrates, the efficiency of their extraction decreases. Anionite sorbs nitrates effectively enough, being both in the chloride mixture and in the sulfate form. Nitrates are effectively desorbed by 2H solutions of sodium chloride and sodium or ammonium sulfate.

4

Development of New Water Deoxidization Systems for Heat and Power Plants

Shabliy Tetyana, Gomelya Mykola, Pohrebennyk Volodymyr, Ivanenko Olena, Nosachova Yuliia

Journal of Ecological Engineering

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2022

|

Vol. 23, nr 1

193--205

EN

The analysis of water conditioning methods for closed water supply systems was carried out in the work. The expediency of using redoxites based on ion exchange materials to combat the corrosion processes in water recirculation systems by preliminary deoxidation of water was shown. Modified KU-2–8, Dowex Mac-3, AB-17–8, Dowex Marathon WBA, AMBERLITE IRA 96 ion exchange resins were used as deoxidizing materials.

5

Improvement of metal separation process from synthetic hydrochloric acid leaching solution of spent lithium ion batteries by solvent extraction and ion exchange

Nguyen Viet Nhan Hoa, Lee Man Seung

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 4

1--17

EN

Spent lithium-ion batteries (LIBs) are good secondary resources for recycle and reuse. To develop a process for the separation of Cu(II), Co(II), Mn(II), Ni(II) and Li(I) with high purity from spent LIBs and circumvent some drawbacks of the previous work, solvent extraction and ion exchange experiments were done in this work. The synthetic hydrochloric acid leaching solution of 3 M was employed. Compared to Aliquat 336 (N-Methyl- N, N, N-trioctyl ammonium chloride), extraction with Cyanex 301 (bis(2,4,4-trimethylpentyl) dithiophosphinic acid) led to selective extraction of Cu(II) over other metal ions. Employing ion exchange with TEVA-SCN resin can completely separate Co(II) over Mn(II). After adjusting the pH of Co(II) free raffinate to 3, Mn(II) was quantitatively extracted by the mixture of Alamine 336 (mixture of tri-octyl/decyl amine) and PC 88A (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) with two stage cross-current extraction. The synthesized ionic liquid (ALi-CY) was used for complete extraction of Ni(II), whereas Li(I) remained in final raffinate. The metal ions in the loaded organic phase were completely stripped with the proper agents (5% aqua regia for Cu(II), 5% NH3 for Co(II), weak H2SO4 solution for Mn(II) and Ni(II) stripping, respectively). The experimental results revealed that purity of the metal ions in stripping solution was higher than 99.9%. A flowsheet was suggested to separate metal ions from the HCl leaching solutions of spent LIBs.

6

Mathematical Prediction of Sorption Processes of Heavy Metals on Cation Exchangers Using the Thomas Model

Koliehova Anastasiia, Trokhymenko Hanna, Gomelya Mykola

Journal of Ecological Engineering

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2021

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Vol. 22, nr 9

232--236

EN

On a production scale, it is advisable to use mathematical models for predicting the treatment of effluents from heavy metal ions, which will increase the efficiency of enterprises. The sorption processes of copper, zinc, nickel and cadmium ions on the KU-2-8 cation exchange resin in the acid form at different concentrations were studied in this scientific work. At the same time, the sorption curves calculated were constructed using the Thomas model. The study results showed that this model very clearly describes the sorption processes of metals on the resin. Thus, it can be used to predict the processes of wastewater treatment in production.

7

Pilotowa stacja badawcza, dedykowana redukcji materii organicznej, w tym wybranych mikrozanieczyszczeń z wód

Zimoch Izabela, Mroczko Dominik

Instal

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2021

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nr 3

41--46

PL

Wciąż rosnące zainteresowanie mikrozanieczyszczeniami oraz zagrożeniami wynikającymi z ich obecności w ekosystemie wodnym, mogą prowadzić do zaostrzania przepisów związanych z ich monitoringiem. W niniejszej pracy zebrano wstępne wyniki analizy efektywności redukcji mikrozanieczyszczeń oraz ogólnej materii organicznej wykorzystując procesy alternatywne dla klasycznych technologii uzdatniania wód przeznaczonych do spożycia przez ludzi. Zaproponowane technologie wdrożone zostały do mobilnej, modułowej stacji badawczej również opisanej w tym artykule. Rozpatrywanymi procesami były: koagulacja, filtracja membranowa, sorpcja i wymiana jonowa oraz fotoliza.

EN

Constantly growing interest in micropollutants and with threats resulting from their presence in the aquatic ecosystem may result in stricter regulations related to their monitoring. This paper presents results of the preliminary micropollutants and total organics reduction effectiveness analysis, with processes alternative to classical technologies of water treatment intended for human consumption. The proposed technologies are implemented in a mobile, modular pilot plant also described in this paper. The considered processes were: coagulation, membrane filtration, sorbtion and ion exchange, and photolysis.

8

Assessment of the properties of HAp micropowders after ion exchange process in silver nitrate solution

Głuszek Marta, Świrska Zuzanna, Kaczorowski Witold, Januszewicz Bartłomiej, Wrotniak Maciej

Engineering of Biomaterials

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2021

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Vol. 24, no. 161

15--20

EN

Bioceramic materials, such as hydroxyapatite (HAp), are characterized by high biocompatibility in the presence of tissues and body fluids without causing toxic or allergic reactions. Hydroxyapatite, due to its similarity to structures found in bones, is used both in the form of powders, e.g. as additives to bone cements, and implants coatings. However, this material is not characterized by antimicrobial properties, therefore attempts are made to improve its properties by introducing additional elements into the hydroxyapatite structure. Thanks to HAp’s high ion-exchange ability, silver can be introduced into its structure. The calcium ions present in the HAp structure can be easily replaced by silver ions to create a material endowed with high biocompatibility and antibacterial properties. The presented study is based on the analysis of the morphology of the modified powders via scanning electron microscopy (SEM), their chemical composition via X-ray energy dispersive spectroscopy (EDS) and chemical structure via X-ray diffraction (XRD) and Raman spectroscopy. The powders obtained through the ion exchange were mixtures of silver phosphates Ag3PO4 and HAp. The highest silver content was found in the sample modified with a 1M concentration of AgNO3 in the aqueous solution. It was also determined that the annealing of the obtained powders under vacuum at 800°C resulted in the formation of metallic silver and a change in the structure of HAp to β-TCP.

9

Promising method of ion exchange separation of anions before reverse osmosis

Trus Inna, Gomelya Mukola, Vorobyova Viсtoria, Skіba Margarita

Archives of Environmental Protection

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2021

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Vol. 47, no. 4

93--97

EN

A method to improve the quality of purified water, reduce the cost of reagents for the regeneration of resin and create low-waste processes have been developed. This paper presents the results of ion exchange separation of sulfates and nitrates using AV-17-8 anion exchange resin in NO3 form. The efficiency of anion separation on the highly basic anion exchange resin AV-17-8 depends on the magnitude and ratio of their concentrations in water. Separation on the AV-17-8 anion exchange resin has been shown to be effective at concentrations of sulfates up to 800 mg/dm3 and nitrates up to 100 mg/dm3. Conditions for regeneration of 10% NaNO3 anion exchange resin were determined. Reagent precipitation of sulfates from the used regeneration solution in the form of calcium sulfate was carried out. Calcium sulfate precipitate can be used in the manufacturing of building materials. The regeneration solution is suitable for reuse. The developed results will allow to introduce low-waste desalination technology of highly mineralized waters.

PL

Celem pracy było opracowano metody poprawy jakości oczyszczonej wody, obniżenia kosztów odczynników do regeneracji żywicy i stworzenia procesów niskoodpadowych. W pracy przedstawiono wyniki rozdziału jonowymiennego siarczanów i azotanów z użyciem żywicy anionowymiennej AB-17-8 w postaci NO3. Skuteczność separacji anionów na wysoce zasadowej żywicy anionowymiennej AB-17-8 zależy od wielkości i stosunku ich stężeń w wodzie. Wykazano, że rozdział na żywicy anionowymiennej AB-17-8 jest skuteczny przy stężeniach siarczanów do 800 mg/dm3 i azotanów do 100 mg/dm3. Określono warunki regeneracji 10% żywicy anionowymiennej NaNO3. Przeprowadzono odczynnikowe wytrącanie siarczanów z zużytego roztworu regeneracyjnego w postaci siarczanu wapnia. Osad siarczanu wapnia może być wykorzystany do produkcji materiałów budowlanych. Roztwór do regeneracji nadaje się do ponownego użycia. Opracowane wyniki pozwolą na wprowadzenie niskoodpadowej technologii odsalania wód wysokozmineralizowanych.

10

Ammonia-Ca-K competitive ion-exchange on zeolites in mining wastewater treatment: batch regeneration and column performance

Chartrand Zachary G., Narbaitz Roberto M., Sartaj Majid, Downey Jason

Journal of Sustainable Mining

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2020

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Vol. 19, iss. 2

58--71

EN

This manuscript addresses the treatment of explosives-impacted mining wastewaters (EIMWW) using ion-exchange to remove elevated levels of ammonia. Repeated batch loading-regeneration cycles were conducted for two commercially available zeolite media used in the treatment of ammonia-laden EIMWW to establish the effects of competing ions and regeneration solution composition. The Northern Ontario EIMWW tested contained 3.87 meq/L total ammonia (TA) as well as 2.85 mg/L K+ and 3.9 meq/L Ca2+. The media studied were a natural clinoptilolite and a modified clinoptilolite (SIR-600). Five regenerant solutions with different NaCl and KCl concentrations were evaluated using batch tests. The presence of potassium in the regenerant was found to hinder the TA exchange capacity of both zeolites. The SIR-600 and the natural clinoptilolite used in conjunction with the 10% NaCl solution featured the best TA exchange capacities, 0.46 ± 0.02 meq TA/g and 0.36 ± 0.05 meq TA/g, respectively. The batch tests showed that both media had a slight preference for K+ over TA. The continuous flow column tests performed using SIR-600 media greatly accentuated the selectivity of K+ over TA. In reaching the same 0.55 meq TA/L breakthrough level, the same modified zeolite column was able to treat five times more volume of a synthetic TA solution than EIMWW.

11

Removal of Humic Substances from Water by Means of Fibrous Ion Exchanger

Wasąg Henryk

Journal of Ecological Engineering

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2020

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Vol. 21, nr 8

229--235

EN

Natural organic substances are found in all natural waters, and especially high concentrations occur in the surface waters. Humic substances, which often constitute the majority of natural pollutants, can be the source of undesirable odor and increased color as well as may accumulate certain toxic substances through sorption or formation of complexes. Another threat connected with the presence of humic substances in water is the possibility of the trihalomethanes (THM) formation during disinfection with chlorine. Additionally, it disturbs most processes employed for treatment of water. Hence, the great interest in the development of the pretreatment methods enabling to reduce the content of humic substances prior to the further water treatment processes. According to many researchers, ion exchange is an effective method for removing humic substances from drinking water supplies. However, the obtained effects are strictly dependent on the properties of the employed ion exchangers. The paper presented the studies on the removal of humic substances from water using fibrous ion exchangers. Owing to their structure, fibrous ion exchangers are characterized by very good kinetics of the sorption process, which enables the application of thin layers with simultaneous high flow velocity. Fiban A-1 – strong base anion fibrous exchanger, synthesized in the Institute of Physical Organic Chemistry of the National Academy of Sciences of the Republic of Belarus – was employed in the presented laboratory studies on the treatment of surface water containing substantial amounts of humic substances (over 10 g/m3). The applied anion exchange resin allows for efficient elimination of humic substances from the treated water, whereas the obtained sorption value, reaching approximately 20 mg/g of ion exchanger allowed treating about 255–270 bed volumes of water under the conditions of the experiment. The exhausted Fiban A-1 ion exchanger can be successfully regenerated using 2% NaCl + 2% NaOH solution, as five consecutive operational cycles showed no reasonable decrease in the amount of purified water.

12

Cooper removal and recovery from aqueous solutions by using selected synthetic ion exchange resins (part I)

Orlof-Naturalna Monika, Bożęcka Agnieszka

Inżynieria Mineralna

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2020

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no. 2, vol. 2

7--14

EN

The paper presents results of research on removal of Cu2+ ions from aqueous solutions by ion exchange method in concentration range of 10–1000 mg/L. For this purpose, following Purolite synthetic ion exchange resins were used: S 910, S 930, S 940, S 950 and C 160. The obtained results were interpreted based on the degree of solution purification and microstructural investigations. The regeneration possibility of used ion exchangers with a 10% hydrochloric acid solution was also investigated. Based on obtained results, it was determined that studied ion exchangers efficiently removed copper(II) ions from aqueous solutions, especially in low concentrations. Microstructural investigation made for tested materials after the sorption process clearly indicate that Cu2+ ions removal process was in accordance with ion exchange mechanism, which was confirmed by recorded SEM images. All ion exchangers except S 910, purified solutions from Cu2+ ions with an efficiency greater than 90% up to a concentration of 100 mg/L. In case of S 930 and S 940 ion exchangers, their efficiency was close to 100%. For higher concentrations, efficiency of studied ion exchangers decreased significantly. The lowest decrease in degree of copper(II) S 910 chelating resin with amidoxime groups was the least efficient. All studied ion exchangers can be regenerated with a 10% hydrochloric acid solution. The efficiency of this process varies from 53.1% to 80.5% depending on the used resins.

PL

W pracy przedstawiono wyniki badań dotyczące usuwania jonów Cu2+ z roztworów wodnych metodą wymiany jonowej w zakresie stężeń 10–1000 mg/L. W tym celu zastosowano żywice jonowymienne firmy Purolite: S 910, S 930, S 940, S 950 i C 160. Otrzymane wyniki zinterpretowano w oparciu o stopień oczyszczenia roztworu i badania mikrostrukturalne. Zbadano również możliwość rege¬neracji użytych jonitów za pomocą 10% roztworu kwasu solnego. Na podstawie otrzymanych wyników stwierdzono, że badane jonity skutecznie usuwały jony miedzi(II) z roztworów wodnych, szcze¬gólnie w niskich stężeniach. Badania mikrostrukturalne wykonane dla badanych materiałów po procesie sorpcji wyraźnie wskazują, że proces usuwania jonów Cu2+ zachodził zgodnie z mechanizmem wymiany jonowej, co potwierdzają zarejestrowane obrazy SEM. Na powierzchni badanych jonitów nie zaobserwowano mikrostrąceń. Wszystkie wymieniacze jonowe z wyjątkiem S 910 oczyszczały roztwory z jonów Cu2+ z wydajnością większą niż 90% do stężenia 100 mg/L. W przypadku jonitów S 930 i S 940 ich skuteczność było bliska 100%. W przypadku większych stężeń wydajność badanych jonitów znacząco malała. Najmniejszy spadek stopnia wydzielenia jonów miedzi(II) zaobserwowano dla kationitu C 160 zawierają¬cego grupy sulfonowe. Najmniej skuteczny okazał się jonit chelatujący S 910 z grupami amidoksymowymi. Wszystkie badane jonity można regenerować za pomocą 10% roztworu kwasu solnego. Wydajność tego procesu waha się od 53,1% do 80,5% w zależności od użytej żywicy jonowymiennej.

13

The removal of sulphate ions from model solutions and their influence on ion exchange resins

Demcak Stefan, Balintova Magdalena, Holub Marian

Ekonomia i Środowisko

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2020

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nr 2

59--70

EN

There is a growing tendency for industries around the globe to diminish the contents of pollutants in industrial wastewaters to an acceptable level. Conventional methods are unfavourable and economically unacceptable, especially for large volumes of wastewaters with a high content of undesirable compounds. In contrast, ion–exchange is a very powerful technology capable of removing contamination from water. This paper analyses a study of ion exchange in Amberlite MB20 and Purolite MB400 resins after sulphate removal from a model solution. For the characterisation of ion exchange in resins, infrared spectroscopy was used. The IR spectra of both ion exchange resins show a similar composition after adsorption. Experiments that are due to this same used matrix in producing. The efficiency of sulphate ion removal and pH changes were also measured. Amberlite MB20 has proven to be a suitable ion exchange resin due to its high effi ciency (about 86%) for the removal of sulphates from solutions with initial concentrations of 100 and 500 mg.L-1, respectively.

14

Sorption and reduction of chromiumion ions by the chelating ion exchanger Diaion CR20

Wójcik Grzegorz

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1382--1393

EN

The chelating ion exchanger Diaion CR20 was applied for removal of chromium(VI) ions in the pH range from 1.5 to 10 and in the presence of 1 M H2SO4. The speciation analysis was used to predict the reduction process. Reduction of chromium(VI) to chromium (III) was observed during the chromium(VI) ions sorption. The kinetic parameters for the pseudo-first-order and pseudo-second-order, Elovich and intraparticle diffusion models were calculated. The most common three isotherm models: Freundlich, Langmuir and Dubinin-Radushkevich were used to describe chromium(VI) uptake. It was proved that the polyamine groups present in selected ion exchanger are able to sorb both chromium(VI) and (III) ions. The maximal sorption capacity towards chromium(VI) ions was estimated at pH 1.5 – 169.49 mg Cr(VI)/g and 159.31 mg Cr(VI)/g in 1 M H2SO4. Both static and column methods were used in the investigations.

15

Synthesis of zeolite A using the waste of iron mine tailings dam and its application for industrial effluent treatment

Izidoro Juliana de Carvalho, Kim Michelle Caroline, Bellelli Valentina Ferraraccio, Pane Mara Cristina, Botelho Junior Amilton Barbosa, Espinosa Denise Crocce Romano, Tenório Jorge Alberto Soares

Journal of Sustainable Mining

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2019

|

Vol. 18, iss. 4

277--286

EN

In November 2015, a dam from iron mining collapsed, which is considered as the largest environmental accident in Brazil. Over than 50 million m³ were released reaching the Doce River and killed 20 people in Mariana. The literature review shows that the mining tailings can be used as raw material to the synthesis of zeolites, which can be used for the wastewater treatment. The aim of this work was the synthesis of zeolites from the Samarco tailings and its application for the treatment of electroplating effluent. The residue was characterized which identified high-iron content for the synthesis of zeolites. The residue was mixed with NaOH (1:1) and the reaction temperature was evaluated from 350 °C to 650 °C. Then, the material was mixed with aluminum source and the effect of time was evaluated. The zeolite was applied to the wastewater treatment from electroplating industry. Results showed that the synthesis of zeolite A was carried out with a fusion step at 450 °C for 1 h using RAS: NaOH ratio 1:1, and further hydrothermal treatment at 100 °C during 4 h. The zinc removal from the wastewater was up to 98% using 50 mL of the solution, 2.5 g zeolite A, 60min and pH 6.4. The main metals presented in the solution were adsorbed up to 90% by the zeolite synthesized. Zinc adsorption by the zeolite fitted better on Langmuir isotherm. The zeolite was used four times in a row and zinc removal declined 98-68%.

16

Treatment of Wastewater Containing a Mixture of Heavy Metal Ions (Copper-Zinc, Copper-Nickel) using Ion-Exchange Methods

Koliehova Anastasiia, Trokhymenko Hanna, Melnychuk Svitlana, Gomelya Mykola

Journal of Ecological Engineering

|

2019

|

Vol. 20, nr 11

146--151

EN

The main aim of the scientific research was to study the ion-exchange processes in the treatment of industrial wastewaters containing a high concentration of heavy metal ions (Cu2+, Zn2+, Ni2+). The sorption results of heavy metal mixtures (Cu-Zn, Cu-Ni) from model solutions of sulfate salts on a strong-acid KU-2–8 cation exchanger in the H+-form were presented. The metals concentration was 10–50 meq/dm3. The efficiency conditions of cation regeneration in Cu2+-Zn2+, Cu2+-Ni2+-forms by 5, 8 and 10 % sulfuric acid solutions were studied. It was shown that the heavy metals from aqueous media can be removed not only from ion exchangers, but can also be restored from regenerative solutions by electrolysis to obtain metals in pure form. In general, the research results showed that the use of ion exchange is very effective in removing the heavy metal ions. The sorption efficiency and regeneration efficiency was about 100%.

17

The Research on the Ammonium Concentrations in City Stocks and Further Sedimentation of Ion-Exchange Concentrate

Malovanyy Myroslav, Sakalova Halyna, Vasylinych Tamara, Kryklyvyi Rostyslav

Journal of Ecological Engineering

|

2019

|

Vol. 20, nr 1

158--164

EN

In this work, the exchange capacity and the selectivity of different ion-exchange products regarding the ammonium ions in treatment processes were measured; the regenerative preparation compounds influence on efficiency of conduction of ion-exchange products regeneration was determined. The adsorption processes were adapted to the known technological schemes of sewage and polluted surface water treatment that was polluted with ammonium ions. There were measured the technological aspects of water treatment by using adsorption on natural dispersed sorbents. The technological schemes of drain water treatment from ammonium ions were developed. The method of simultaneous removal of highly concentrated nitrogen and phosphorus was analyzed by physical and chemical precipitation, forming struvite, a by-product of magnesium ammonium orthophosphate hexahydrate. The analyses were conducted at various molar ratios of magnesium and phosphate ions and at various pH values. The comparative thermal analysis of chemical precipitation products and pure struvite was performed. The optimal conditions were identified to experience the maximum efficiency of simultaneous removal of ammonium nitrogen and phosphate ions from wastewater, forming MgNH4PO4·6H2O.

18

Mathematical modeling singularly perturbed processes of water softening on sodium-cationite filters

Safonyk Andrii, Prysiazhniuk Ihor, Prysiazhniuk Olena, Naumchuk Oleksandr

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2019

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T. 9, nr 1

37--40

EN

Mathematical model of the process of water softening using ion exchange pre-treatment of waters to desalination, with a view to removal of scale forming components, such as calcium and magnesium, are formed in the paper. In this process, no additional chemicals, except for brines formed during desalination, are required for regeneration of ion-exchanger in operation cycles. An asymptotic approximation of a solution of a corresponding model problem is constructed. Theoretical description and modelling assumptions included the set of differential equations of mass balance, initial, boundary and operational conditions. The paper deals with the development of a computer model for description and prediction of the performance of ion exchange columns.

PL

W pracy opracowano matematyczny model procesu zmiękczania wody przy użyciu wstępnej obróbki wody poprzez wymianę jonową do odsalania w celu usunięcia składników tworzących kamień, takich jak wapń i magnez. W procesie tym dla regeneracji wymiennika jonowego w cyklach roboczych nie trzeba wykorzystywać dodatkowych chemicznych czynników za wyjątkiem solanek, które powstają podczas odsalania. Opracowano asymptotyczne przybliżenie odpowiedniego rozwiązania z modelem. Opis teoretyczny i założenia modelu obejmują szereg równań różniczkowych bilansu masy, warunków początkowych, granicznych i eksploatacyjnych. Rozpatrzono opracowanie modelu komputerowego dla opisu i prognozowania działania kolumn wymiany jonowej.

19

Removal of chromium(VI) from wastewater through ion exchange. Kinetic and scale up studies

Ahmad Syed Waqas, Zafar Muhammad Shahzad, Ahmad Sajjad, Zia-Ul-Haq M., Ashraf Muhammad, Rabbani Javed, Ullah Sami

Environment Protection Engineering

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2019

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Vol. 45, nr 1

17--29

EN

Chromium(VI) ions were removed from industrial wastewater. In this regard, a rig was fabricated carrying alkaline anion resin. Various experiments were carried out by varying pH, temperature and volumetric flow rate of solution by employing a rig to study the kinetics of the ion exchange process. The rate constant (k) and maximum solid phase concentration of exchanged solute (q0) were calculated using the Thomson equation to scale up the purification process of industrial runoff of chromium(VI) from the tanning, photography and ceramic industry. Experimental optimization revealed that developed setup will remove chromium(VI) to a level of 5 mg/dm3 from 300 mg/dm3 in 40 000 dm3 of wastewater. To achieve the best results for the flow rate of 10 000 3 3/day, 12.03 kg of anionic resin were recommended by fixing the pH of the setup at 7.4 while maintaining the treatment temperature at 20 °C.

20

Otrzymywanie wody zdemineralizowanej metodą destylacji membranowej

Gryta M.

Przemysł Chemiczny

|

2018

|

T. 97, nr 8

1409--1411

PL

Przedstawiono wyniki badań otrzymywania wody zdemineralizowanej z wody powierzchniowej w procesie destylacji membranowej. Proces prowadzono stosując kapilarne membrany wykonane z polipropylenu. Badano wpływ temperatury nadawy (313-333 K) oraz stopnia odzysku wody (75-90%) na powstawanie osadów na powierzchni membran (scaling) oraz na wydajność procesu. Niezależnie od stężenia nadawy uzyskiwano czystą wodę o małej przewodności właściwej. Prowadzenie procesu przy wysokim stopniu odzysku (90%) spowodowało spadek wydajności procesu z powodu obecności osadów na powierzchni membran. Intensywność zanieczyszczenia membran znacznie zmniejszono, gdy wodę zasilająca podgrzewano tylko do 313 K, a współczynnik odzysku wody wynosił 75%. Morfologię oraz skład osadów badano metodą mikroskopii skaningowej połączonej z mikroanalizą rentgenowską.

EN

Membrane distn. was used for the prodn. of demineralized H2O from surface water. The effect of feed temp. and the degree of H2O recovery on the scaling layer formed on the membrane surface and process effectiveness was evaluated. A high H2O recovery degree (90%) was achieved, but the accelerated formation of deposits on the membrane surface (scaling) was obsd., esp. for feed temp. 333 K and H2O recovery degree above 75%. The morphol. and compn. of the filter cake was studied by scanning electron microscopy coupled with energy-dispersing spectrometry.