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1

New boron selective sorbents for sorption – membrane hybrid system

Dach Barbara, Bryjak Marek, Bryjak Jolanta, Łużny Rafał

Polimery

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2022

|

Vol. 67, nr 4

158--161

EN

The synthesis and properties of core-shell sorbents dedicated to the removal of borates from aqueous solutions were described. By modification of polymer matrices with vinylbenzyl chloride followed by its derivatization with N-methyl glucamine a new kind of sorbents were obtained. The testing of boron sorption reviled that the process efficiency was related to the pore diameter and the content of ligand in the sorbent. The best material for use in a hybrid system, where boron is absorbed by fine particles and removed in microfiltration, was Poropak Q with a specific surface area of 300 m2/g.

PL

Opisano syntezę i właściwości sorbentów typu rdzeń-otoczka przeznaczonych do usuwania boranów z roztworów wodnych. Poprzez modyfikację matryc polimerowych chlorkiem winylobenzylu, a następnie ich derywatyzację za pomocą N-metyloglukaminy otrzymano nowy rodzaj sorbentów. Badania sorpcji boru wykazały zależność wydajności procesu od średnicy porów i zawartości ligandu w sorbencie. Najlepszym materiałem do zastosowania w systemie hybrydowym, w którym bor jest absorbowany przez drobne cząstki i usuwany w procesie mikrofiltracji, okazał się Poropak Q o powierzchni właściwej 300 m2/g.

2

The Effect of Surfactants with Steric Hindrance on the Physicochemical and Tribological Properties of Metalworking Fluids

Sułek Marian Włodzimierz, Przepiórka Jacek, Kulczycki Andrzej, Hreczuch Wiesław

Tribologia

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2020

|

nr 2

75--84

PL

W poprzednich pracach postulowano zastosowanie roztworów surfaktantów jako oryginalne rozwiązanie przy formułowaniu składu MWF. Negatywną cechą niektórych z tych cieczy była nadmierna pianotwórczość, której zmniejszenie przez wprowadzenie hydrofobowych inhibitorów piany, było ograniczone. Dlatego też zaplanowano syntezę nowych, oksyalkilenowanych pochodnych alkoholu 2-etyloheksylowego i sulfobursztynianu otrzymanego z tego rodzaju alkoholu. Ze względu na zawadę sferyczną związki te charakteryzują się niską pianotwórczością. Wodne roztwory tych surfaktantów poddano badaniom fizykochemicznym i tribologicznym.

EN

n earlier studies, it has been postulated that solutions of surfactants should be used as an original solution for formulation of Metal Working Fluids (MWF) compositions. The negative feature of some of the fluids was their excessive foamability whose reduction, by introducing hydrophobic foam inhibitors, was limited. Therefore, a synthesis of new oxyalkylated derivatives of 2-ethylhexyl alcohol and sulfosuccinate obtained from this alcohol was planned. Due to steric hindrance, these compounds exhibit low foamability. Aqueous solutions of these surfactants were subjected to physicochemical and tribological tests.

3

Development of an extraction procedure and analysis of electrostatically stabilized silanates from aqueous solutions

Jabłońska Joanna, Kluska Mariusz, Erchak Nikolai, Popiel Stanisław

Oceanological and Hydrobiological Studies

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2020

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Vol. 49, No. 3

247--254

EN

The analyzed organosilicon derivatives of electrostatically stabilized silanates belong to a group of pentacoordinated compounds. These derivatives are:1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at,1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-methylcyclopentan-3-on)at,1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-(i-propyl)cyclopentan-3-on)at. In the course of the work, the extraction process and optimization of conditions for separation and determination of a mixture of electrostatically stabilized silanates were carried out using capillary isotachophoresis. Proper leading electrolytes were elaborated developed and the terminating electrolyte:4,4’-bis[(1-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at] was proposed. The extraction process involved the use of three stationary phases: octadecyl, octyl and phenylpropyl. The highest recovery values, approx. 94%, were obtained on the phenylpropyl column. The optimum time of analysis by the isotachophoretic technique did not exceed 12 min. The developed method of separation and determination of electrostatically stabilized silanates expands the possibility of research on biological activity of this group of compounds in aqueous solutions and surface water vegetation.

4

Study of the Magnetic Water Treatment Mechanism

Vaskina Iryna, Roi Ihor, Plyatsuk Leonid, Vaskin Roman, Yakhnenko Olena

Journal of Ecological Engineering

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2020

|

Vol. 21, nr 2

251--260

EN

The main problem of widespread introduction of magnetic water treatment (MWT) in the processes of water and wastewater treatment is the lack of modern research aimed at studying the mechanisms of MWT effects, in particular the influence on the physicochemical properties of aqueous solutions. This study explains the effect of MWT taking into account the physical and chemical properties of aqueous solutions due to the presence of the quantum differences in water molecules. All of the MWT effects are related to the change in the physicochemical properties of aqueous solutions. It is due to the presence of two types of water molecule isomers and their librational oscillations. The result of MWT is a violation of the synchronism of para-isomers vibrations, with the subsequent destruction of ice-like structures due to the receiving of energy from collisions with other water molecules (ortho-isomers). One of the most important MWT effects includes the change in the nature and speed of the physicochemical processes in aqueous solutions by increasing the number of more physically and chemically active ortho-isomers. The MWT parameters specified in the work allow explaining the nature of most MWT effects and require developing the scientific and methodological principles for the implementation of the MWT process and mathematical modeling of the MWT process in the water and wastewater treatment. It can be used in the design of the MWT devices taking into account the constructive and mode parameters of MWT devices.

5

Wpływ dodatku środków powierzchniowo czynnych lub polimerów na opór przepływu roztworów wodnych

Malcher Tadeusz

Przemysł Chemiczny

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2019

|

T. 98, nr 9

1427--1429

PL

Dodatki środków powierzchniowo czynnych lub polimerów wywołują zmniejszenie oporów przepływu mediów. Przedstawiono i porównano 3 sposoby ograniczenia oporów przepływu i efekty towarzyszące temu zjawisku.

EN

Fundamentals and a review with 19 refs.

6

Alginiany jako sorbenty w procesach usuwania radionuklidów z rozcieńczonych roztworów wodnych

Oszczak-Nowińska Agata, Fuks Leon

Przemysł Chemiczny

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2019

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T. 98, nr 10

1659--1661

PL

Przeprowadzono syntezę sferycznych alginianów wapnia, strontu i baru. Zbadano podstawowe właściwości fizykochemiczne tych sorbentów oraz określono ich zdolność sorpcyjną, a także możliwości ich użycia do usuwania radionuklidów Am-241, Eu-152, Sr-85 i Cs-137 z rozcieńczonych roztworów wodnych. W celu określenia zdolności sorpcyjnej alginianów wyznaczono współczynniki dekontaminacji oczyszczanych roztworów oraz wartości współczynników podziału Kd. Stwierdzono, że zdolność sorpcyjna alginianów nie zależy w sposób istotny od kationu metalu żelującego sorbent alginianowy, ale zależy od wartości ładunku sorbowanego kationu radionuklidu.

EN

Spheric Ca, Sr and Ba alginate sorbents were prepd. and used for removal of Am-241, Eu-152, Sr-85 and Cs-137 nuclides from their aq. solns. The sorbability was detd. as decontamination factors and distribution coeffs. The sorbability did not depend on alginate sorbent-gelling cations but increased with increasing the charge of the radionuclide sorbed.

7

Phenol Biosorption from Polluted Aqueous Solutions by Ulva lactuca Alga Using Batch Mode Unit

Abbas Mohammed Nsaif, Al-Hermizy Suadat Mustafa Mohammed, Abudi Zaidun Naji, Ibrahim Thekra Atta

Journal of Ecological Engineering

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2019

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Vol. 20, nr 6

225--235

EN

This paper is related to study the using sea lettuce (Ulva lactuca) as a low-cost adsorbent for removing the phenol compounds from aqueous solutions by adsorption under different operating conditions in a batch unit. The SEM and FTIR tests were performed to determine the morphological characteristics and the functional groups existing on the adsorbent material, respectively, while the surface area was identified by means of two techniques which were blue color method and BET method. The results of the adsorption experiments showed that the efficiency of the removal process is inversely proportional with initial concentration of phenol, pH and temperature; while the efficiency was directly proportional to adsorbent amount, agitation speed and treatment time. The results showed that the percentage of removal of phenol from processed water solutions ranged from 25.446% to 90.125%. The Langmuir and Freundlich isotherm models were chosen to estimate the amounts of phenol adsorption by the sea lettuce powder. The kinetic study shows that the adsorption was obeyed pseudo second order also the thermodynamic parameters were calculated.

8

Biosorption of Heavy Metals from Synthetic Wastewater by Using Macro Algae Collected from Iraqi Marshlands

Bahaa Shaymaa, Al-Baldawi Israa Abdulwahab, Yaseen Safaa Rasheed, Abdullah Siti Rozaimah Sheikh

Journal of Ecological Engineering

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2019

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Vol. 20, nr 11

18--22

EN

Biosorption is fast, effective and low cost process. It takes place in a wide range of temperature and it can be used for almost all types of heavy metals. The aim of this study was to investigate the ability of locally collected green macro algae to remove copper, chromium and cadmium from synthetic wastewater. The fresh algae were converted into dry powder as biosorbent. In the investigations, 1 g of macro algae powder was exposed to synthetic waste water contaminated with 10 mg/L concentration of copper, chromium and cadmium in separate exposure for 2 hours. The best removal efficiency for copper, chromium and cadmium were 70%, 80% and 85%, respectively, from the initial concentration of 10 mg/L. While macro algae are abundantly available in marshlands of south Iraq, it can be preferably utilized as biosorbent to remove heavy metals from the industrial wastewater.

9

Photoacoustic Method as a Tool for Analysis of Concentration-Dependent Thermal Effusivity in a Mixture of Methyl Alcohol and Water

Ponikwicki Nikodem, Szczepanik Łukasz, Gondek Joanna, Linde Bogumił B.J., Skrodzka Ewa Barbara, Molchanov Vladimir, Yushkov Konstantin B., Grechishkin Rostislav

Archives of Acoustics

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2019

|

Vol. 44, No. 1

153--160

EN

It has been shown in the present paper that exploitation of the experimental potential of a photoacoustic technique can provide information on a type of intermolecular interactions in aqueous mixtures containing organic liquids, when the basic parameters of these mixtures, such as density, ρ, specific heat, cp, or thermal conductivity, λ, are unknown. Earlier investigations of concentration dependence of effusivity in different aqueous solutions of organic liquids demonstrated that the photoacoustics method is a sensitive tool to identify hydrophobic properties of such liquids. In our experiment this suggestion was exploited for a solution of methanol which is known to display much weaker hydrophobicity than other alcohols. It was confirmed that the location of extreme deviations from linearity for the thermal effusivity, Δe, agrees well with that of characteristic points for the isentropic compressibility coefficient, κS, and the excess molar volume, VEm , as a function of the concentration.

10

The Effect of the Formation of Polymer/Surfactant Complexes on Selected Tribological Properties of Their Aqueous Solutions

Sułek M. W., Jedynak R.

Tribologia

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2018

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nr 5

117--122

EN

Aqueous solutions of sodium alkyl sulphate (surfactant) and polyvinylpyrrolidone (polymer) whose physicochemical properties, including complexing ability, have been widely described in the literature were proposed as a model lubricant. It has been assumed that aqueous solutions of these compounds will favourably modify lubricating properties of water under high load conditions. For this purpose, measurements were made on a four-ball apparatus (T-02 Tester) for aqueous solutions of these compounds. Two kinds of tests were carried out: at constant loads (2, 3, and 4 kN) and variable loads within the range of 0 to 7.2 kN. Unexpectedly, high decreases in motion resistance and wear as well as an increase in antiseizure properties were found in relation to water as a base. The results obtained are so promising that solutions with an optimized composition can find practical applications. The surprisingly high effectiveness of the additives used results from the formation of surfactant/polymer complexes. These adducts adsorb at the interface, and, under friction conditions, they form a lubricant film capable of carrying high loads.

PL

Jako modelową substancję smarową zaproponowano wodne roztwory alkilosiarczanu sodu (surfaktant) i poliwinylopirolidonu (polimer), których właściwości fizykochemiczne, w tym zdolność do kompleksowania, zostały szeroko opisane w literaturze. Postawiono tezę, że wodne roztwory tych związków będą korzystnie modyfikowały właściwości smarne wody w warunkach wysokich obciążeń. W tym celu dla wodnych roztworów tych związków wykonano pomiary na aparacie czterokulowym (Tester T-02). Przeprowadzono 2 rodzaje testów: przy stałych obciążeniach (2, 3, 4 kN) oraz przy zmiennym obciążeniu w przedziale zmienności od 0 do 7,2 kN. Stwierdzono nieoczekiwanie duże obniżenie oporów ruchu i zużycia oraz wzrost właściwości przeciwzatarciowych w odniesieniu do wody jako bazy. Uzyskane wyniki są na tyle obiecujące, że roztwory o zoptymalizowanym składzie mogą znaleźć zastosowanie praktyczne. Niespodziewanie wysoka efektywność stosowanych dodatków jest konsekwencją tworzenia kompleksów surfaktanta z polimerem. Addukty te adsorbują na granicy faz, a w warunkach tarcia tworzą film smarny zdolny do przenoszenia wysokich obciążeń.

11

Preparation of sorbent with a high active sorption surface based on blast furnace slag for phosphate removal from wastewater

Kostura B., Dvorsky R., Kukutschová J., Študentová S., Bednář J., Mančík P.

Environment Protection Engineering

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2017

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Vol. 43, nr 1

161--168

EN

A new method has been presented, which leads to a significant improvement of the adsorption ability of blast furnace slag (BFS). An ultra-high pressure water jet mill cavitation disintegrator and a controlled vacuum freeze dryer were used to disintegrate amorphous BFS. Specific surface areas of both BFS and disintegrated slag (BFS-D) were measured using the SBET method. BFS-D was obtained with an average particle size of 198 nm and with 27-times bigger free specific surface area than that of original BFS. The BFS-D was tested as an adsorbent of phosphate from aqueous solutions. Adsorption data were analysed using the Freundlich and Langmuir adsorption isotherms. The BFS-D after phosphate adsorption was characterized using FTIR. The theoretical adsorption capacity of the BFS-D was 30.49 mg P/g, which represents an increase by 126.7% compared to the original BFS. Surface precipitation of hydroxyapatite was dominant retention mechanism.

12

Adsorption of reactive Orange 4 on sesame stalks. Modeling, kinetics and equilibrium

Tanyildizi M. S., Demirci Y.

Environment Protection Engineering

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2017

|

Vol. 43, nr 3

5--20

EN

Placket Burman design (PBD) and central composite design (CCD) were employed to study the adsorption of Reactive Orange 4 (RO4) on sesame stalk. In the study conducted with the PBD, a total of seven parameters (initial dye concentration, initial pH of solution, temperature, amount of adsorbent, particle size, contact time, and shaking speed) were studied, and four of these were found to influence the adsorption of dye. A mathematical model equation was developed by using the CCD. Analysis of variance (ANOVA) indicated a high coefficient of determination (R2= 0.93). The initial dye concentration, amount of sesame stalk, contact time, and initial pH were shown to be very significant (p < 0.05) for RO4 adsorption. The data for the adsorption of RO4 at equilibrium on sesame stalk were analyzed by the Langmuir, Freundlich, and Tempkin models. Temperature increase from 20 to 60 degrees C enhanced the adsorption capacity of the monolayer from 84.75 to 178.57 mg/g. The rate constants were calculated for various initial concentrations of the dye by using pseudo-first and pseudo-second order kinetic and particle diffusion adsorption models. The kinetic evaluations showed that the experimental data were in accordance with the pseudo-second order model.

13

Usuwanie jonów metali z wody za pomocą membran polimerowych

Krasoń J., Pietrzak R.

Przemysł Chemiczny

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2016

|

T. 95, nr 4

851--855

PL

Membrany na bazie octanu celulozy modyfikowane poliwinylopirolidonem użytym w roli czynnika powodującego powstawanie porów w membranie zastosowano w procesach usuwania jonów żelaza oraz miedzi z roztworów wodnych. Określono parametry strukturalne oraz efektywność usuwania jonów miedzi i żelaza z fazy ciekłej z wykorzystaniem otrzymanych membran. Zaobserwowano wpływ zawartości polimeru porotwórczego na wartości przepływów przed filtracjami. Stwierdzono ponadto wpływ ilości zarówno polimeru membranotwórczego, jak i porotwórczego na wartości oporów w membranach po przeprowadzonych procesach filtracji jonów żelaza i miedzi.

EN

Four cellulose acetate-based membranes were modified with polyvinylpyrrolidone (PVP) in DMF and used for removal of iron and copper ions from their solns. The addn. of PVP (1 or 3% by mass) resulted in pore formation in the membranes and in a decrease in their contact angle and filtration resistance.

14

Ecological cutting fluids

Sułek M. W., Seweryn A., Bąk-Sowińska A., Bujak T.

Problemy Eksploatacji

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2016

|

no. 4

107--118

EN

Industrial cutting fluids are used in the form of emulsions and microemulsions of the o/w type. They pose a hazard for the natural environment and the personnel working with them. This paper presents a new type of safe cutting fluids: aqueous solutions of surfactants. Physicochemical, tribological and operational tests were carried out in order to optimize the compositions of the cutting fluids. Physicochemical and operational properties of the optimized cutting fluid are comparable to those of the best equivalents available on the market.

PL

Stosowane w praktyce przemysłowej ciecze obróbkowe występują w formie emulsji i mikroemulsji typu o/w. Stanowią one zagrożenie dla środowiska naturalnego oraz ludzi na stanowiskach pracy. W przedstawionym artykule zaprezentowano nowy rodzaj bezpiecznych w stosowaniu cieczy chłodząco-smarujących. Są nimi wodne roztwory aktywne powierzchniowo. Dla zoptymalizowanych składów cieczy obróbkowych przeprowadzono badania fizykochemiczne, tribologiczne oraz eksploatacyjne. Ciecz obróbkowa o zoptymalizowanym składzie ma porównywalne a nawet korzystniejsze właściwości fizykochemiczne i użytkowe w porównaniu z ich najlepszymi odpowiednikami rynkowymi.

15

Zastosowanie soli sodowej kwasu N,N-bis(karboksymetylo)glutaminowego w procesie usuwania jonów metali z roztworów wodnych

Pańczuk-Figura I., Kołodyńska D., Rusek P., Hubicki Z.

Przemysł Chemiczny

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2015

|

T. 94, nr 3

348-352

PL

Przedstawiono wyniki badań dotyczących wykorzystania kwasu N,N-bis(karboksymetylo) glutaminowego jako biodegradowalnego czynnika kompleksującego w procesie usuwania jonów metali z roztworów wodnych.

EN

Cu²⁺ and Pb²⁺ ions were complexed with Na N,N-bis(carboxymethyl) glutamate in aq. soln. and removed by sorption on 3 com. ion-exchange resins at pH 4–8.5 for 1–180 min. The sorption kinetics was described by the pseudo-second order model. The best ion-exchange resin showed a capacity 179.4 mg/g for Cu²⁺ and 184.96 mg/g for Pb²⁺ ions.

16

Zastosowanie metody elektrokalorymetrycznej do wyznaczania ciepła właściwego wodnych roztworów soli sodowej karboksymetylocelulozy

Prałat K.

Inżynieria i Aparatura Chemiczna

|

2015

|

Nr 1

14--15

PL

Praca przedstawia wyniki badań doświadczalnych wyznaczania ciepła właściwego cieczy newtonowskich: wody, gliceryny, oleju rzepakowego oraz wodnych roztworów soli sodowej karboksymetylocelulozy Podczas pomiarów wykorzystano metodę elektrokalorymetryczną. Obliczone wartości ciepła właściwego dla cieczy wzorcowych były w zakresie 1660÷ 4234 [J/(kg K)] i nie różniły się od danych literaturowych więcej niż o 1,1%. W przypadku roztworu polimeru ciepło właściwe wzrasta wraz z jego stężeniem. Istotny wpływ na otrzymane wyniki ma również masa molowa. Najwyższe wartości ciepła właściwego uzyskano dla Na-CMC o masie molowej 7-105 kg/kmol i stężeniu 0,005 kg polim./kg. Otrzymany wynik był o ponad 15% wyższy od ciepła właściwego wody.

EN

Results of the specific heat determination of three Newtonian liquids and six carboxymethylcellulose sodium salt aqueous solutions are presented and discussed in the paper. The electrocalorimetric method was used during measurements. The calculated values of specific heat coefficients were in a range of 1660÷ 4234 [J/(kg.K)] for standard liquids and did not deviate from the literature values more than 1.1 %. The highest values were obtained for Na-CMC with a molar mass of 7-105 [kg/kmol] and concentration of 0.005 [kg p/kg]. This result was more than 15% higher compared to water. Keywords: specific heat, Na-CMC aqueous solutions, calorimetric method

17

Ocena przydatności iłołupków bentonitowych do usuwania fenolu z roztworów wodnych

Kaleta J., Papciak D., Puszkarewicz A.

Rocznik Ochrona Środowiska

|

2013

|

Tom 15, cz. 3

2352--2368

EN

The paper presents the results of laboratory testing of the potential use of bentonite clay from Dynowskie Foothills for removing phenol from model water solutions. Both natural clays and those treated with sodium carbonate, hydrochloric and sulfuric acids were used. The paper shows the characteristics of phenols occurring in natural water. The sources of phenols, i.e. household and industrial wastewater as well as municipal landfills and damps are given. The aim of the experiments was to determine a quantitative formulation of the adsorption process, as well as to describe the effect of various factors on the process itself. An attempt was made to solve the tasks using model experimental setups. Model phenol solution, concentration of 20,00 mg/L, prepared using distilled water was applied as an adsorptive. The phenol concentration in model solutions was determined using the linear relationship between the concentration of this compound and the absorbency value at the wavelength of 254 nm. The absorbency value was read with a SHIMADZU UV – 1601 spectophotometer using quartz cuvets with an absorbing layer 10 mm thick. The results obtained in a successive series of experiments performed under static conditions were described using basic izoterm equations i.e. those of Freundlich, Langmuir and BET. Freundlich’s equations best described the process. The adsorption capacity of the active clays tested was calculated on the basis of the isotherms. Natural clay had an adsorptive capacity of 0,74 mg/g, clay modified with hydrochloric acid 2,41 mg/g, clay modified with sulfuric acid 1,83 mg/g and clay modified with sodium carbonate 0,50 mg/g. Dynamic conditions were realised by the column filtration method. The adsorption columns were made of organic glass 32 mm in diameter, the filling height was 750 mm, filtration rate – 12 m/h. Filtration was performed from the top downwards. Filtration lasted each time until the moment of bed exhaustion, i.e. such a point where the concentration in the discharge becomes equal to that of the initial solution. The sorption effectiveness under flow conditions for bentonite clays was 100%. On the basis of the results obtained, the breakthrough curves, the so-called iso-planes, were prepared and served in turn to determine the adsorption capacities under flow conditions. The adsorptive capacities were higher than those determined through static conditions and these were 15,9 mg/g, 19,9 mg/g, 18,8 mg/g and 15,2 mg/g for natural clay, clay modified with hydrochloric acid, clay modified with sulfuric acid and clay modified with sodium carbonate, respectively. The clay modified with sodium hydrochloric acid exhibited the highest values of adsorption capacities, as determined under both static and flow conditions. Modification of samples with hydrochloric and sulfuric acids appeared advantageous for both technological and economic reasons. The exit curves (iso-planes) were used to determine the mass penetration zone (the adsorption front height), as well as to calculate the rate at which the mass-exchange zone advanced. The adsorption front height for the carbons tested was 3–5 times lower than the adsorption bed height, thus confirming the high effectiveness of clays in phenol removal. Despite this considerable superiority of active carbon as sorbent, bentonite clays may be taken into account in designing process systems, especially as insulating materials in relation to active carbon. The array of water conditioning processes to be employed for phenol polluted water should in each case be preceded by detailed and thorough technological studies.

18

Wykorzystanie popiołów ze spalania mączki mięsno-kostnej do usuwania jonów Zn i Pb z roztworów wodnych

Staroń A., Wzorek Z., Banach M.

Przemysł Chemiczny

|

2013

|

T. 92, nr 5

719-723

19

Kinetic study of the photoelectrochemical gold recovery from diluted chloride solutions

Wojnicki M., Tokarski T., Kwolek P.

Archives of Metallurgy and Materials

|

2013

|

Vol. 58, iss. 3

709--716

EN

Au(III) was recovered from an acidic aqueous solution via a photoreduction technique under UV light irradiation. Titanium dioxide nanopowder was applied as a photocatalyst. Gold was deposited onto TiO2 surface in the form of nanoparticles with average dimensions between 20 and 30 nm. The influence of the Au(III), TiO2 and methanol initial concentrations on the reaction rate was determined. It was shown, that the rate of the gold photoreduction strongly depends on the concentration of TiO2 and methanol. The recovery of gold from the diluted acidic solutions containing as much as 1.97 and 0.197 mg/dm3 of Au(III) was also carried out. Obtained results suggest, that it is possible to recover about 45% of gold. Besides the losses during the filtration process due to the application of very fine TiO2 particles, oxygen dissolved in the solution as well as the hydrogen ions may take part in parasitic reactions and thus decrease the Au yield.

PL

Przeprowadzono odzysk jonów Au(III) z kwaśnych, chlorkowych roztworów wodnych metodą fotoredukcji pod wpływem światła UV. Jako fotokatalizator wykorzystano proszek dwutlenku tytanu o rozmiarach nanometrycznych. W wyniku redukcji kompleksu chlorkowego Au(III), na powierzchni TiO2 otrzymano fazę metaliczną w formie nanocząstek o rozmiarach w zakresie od 20 do 30 nm. Zbadano wpływ stężeń początkowych Au(III), TiO2 i metanolu. Badania wykazały, że szybkość fotoredukcji Au(III) silnie zależy od stężenia dwutlenku tytanu i metanolu. Przeprowadzono również badania nad odzyskiem złota z rozcieńczonych roztworów zawierających 1.97 i 0.197 mg/dm3 Au(III). Otrzymane wyniki wskazują, że przyjęta metoda pozwala odzyskać około 45% złota z roztworu. Niska wydajność procesu może być spowodowana stratami w procesie filtracji związanymi z zastosowaniem nanokrystalicznego TiO2, tlenem rozpuszczonym w roztworze oraz jonami H+, które mogą ulegać redukcji w konkurencyjnych, równoległych reakcjach.

20

Zastosowanie adsorbentów zeolitowych do usuwania jonów uranylowych z roztworów wodnych

Gajowiak A., Majdan M.

Przemysł Chemiczny

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2011

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T. 90, nr 3

417-423