Wyniki wyszukiwania - BazTech

1

The flotation separation of barite-calcite using sodium silicate as depressant in the presence of sodium dodecyl sulfate

Chen Xiong, Gu Guohua, Liu Donghui, Zhu Renfeng

Physicochemical Problems of Mineral Processing

|

2019

|

Vol. 55, iss. 2

346--355

EN

The flotation separation of barite from calcite using sodium dodecyl sulfate (SDS) as the collector and sodium silicate (SS) as the depressant has been concretely studied in this paper. The results show that SDS has high collecting ability for both barite and calcite and that the flotation separation of barite from calcite cannot be achieved by using SDS alone. The depressant sodium silicate has a selective depression effect on calcite by the control of the pulp pH at 9.0 in the presence of SDS. Through locked cycle tests, a concentrate containing 95.54% BaSO4 can be obtained from an actual ore containing 24.5% BaSO4, with a recovery of 86.11%. The zeta potential measurements, adsorption analysis and infrared spectrum studies reveal that the pre-adsorption of sodium silicate strongly favors the adsorption of SDS on the calcite surface and adversely affects SDS adsorption on the barite surface. This property is the reason for the selective depression of SS on calcite.

2

Removal of Pb(II) ions from aqueous solution using complexation-ultrafiltration

Şahin D., Tascıoglu S.

Polish Journal of Chemical Technology

|

2018

|

Vol. 20, nr 2

80--84

EN

Ligand-modified micellar-enhanced ultrafi ltration (LM-MEUF) is a membrane technique based on a separation process which can be used for removal of target metals from an aqueous solution. This method involves adding both a metal complexing ligand and surfactant molecule to the aqueous solution under conditions where most of the molecules are present as micelles. This ligand can be attached to the surface of micelles by solubilization and forms the ligand complexes with the metal ion. The aqueous solution is then treated through a membrane which has to be smaller pore sizes than those of the complexes. Hence, permeate water is then purified from the heavy metals. In this study, divalent lead is the target ion in a solution. Filtration experiments were performed with ultrafi ltration membrane system, equipped with a regenerated cellulose membrane with a 5000 Daltons cutoff. The pressure was fixed at 4.0 bar with a permeate flow rate of 500 mL min–1 . Complexes of Pb2+ ions with three ligands were investigated in micellar medium of different surfactants at different pH values to determine the ligands which could provide separation. Different parameters affecting the percentage rejection of the Pb2+ , such as pH and surfactant concentration were also discussed. Results have shown that the maximum percentage of the Pb2+ ions rejection were obtained using sodium dodecyl sulfate (SDS) as a surfactant and dithizone (DZ) as the lead-specifi c ligand. A waste stream sample from a battery plant was subjected to LM-MEUF process in the optimum conditions determined in this study and it was shown that Pb2+ ions in a waste stream could be removed by LM-MEUF effectively.

3

The Method of Removal Yttrium (III) and Ytterbium (III) From Dilute Aqueous Solutions

Lobacheva O., Dzhevaga N., Danilov A.

Journal of Ecological Engineering

|

2016

|

Vol. 17, nr 2

38--42

EN

Yttrium (III) and ytterbium (III) cations ion flotation from diluted aqueous solutions in the presence of chloride ions using sodium dodecyl sulfate as collector agent were studied. Y (III) and Yb (III) distribution and recovery coefficients as a function of aqueous phase рН value at different sodium chloride concentrations were received. Yttrium (III) and ytterbium (III) chloro and hydroxo complexes instability constants were calculated. The calculation of separation coefficient at рН specified values depending on chloride ion concentration was conducted. Maximum separation coefficient was observed when chloride concentration of 0.01 M is 50 at рН 7.8. Ksep is minimal in nitrate medium ans is 3 at рН 7.0. At sodium chloride concentration of 0.05 М Ksep is 9 at рН 7.8.

4

Surfactant assisted removal of engine oil from synthetic soil

Ramamurthy A. S., Chen Z., Li X., Azmal M.

Environment Protection Engineering

|

2015

|

Vol. 41, nr 2

67--79

EN

Effectiveness of surfactants SDS (sodium dodecyl sulfate), AOT (sodium dioctyl sulfosuccinate) and Brij 35 (polyoxyethylene lauryl ether) in removing residual oil from soils have been determined. Experimental results indicated that oil desorption efficiencies with surfactants are 7 to 18 times higher than using water alone. 0.6% Brij 35 at was the most effective surfactant to remove oil from soil, and it did not display any significant change in oil desorption with pH changes. A comparison study also showed that pore volume was a more significant parameter than soil washing flow rate to improve oil desorption.

5

Wpływ polielektrolitu na skuteczność ultrafiltracji roztworów wodnych zawierających barwniki organiczne i substancję powierzchniowo czynną

Majewska-Nowak K.

Ochrona Środowiska

|

2006

|

R. 28, nr 4

3-10

PL

Oceniono wydajność i skuteczność procesu ultrafiltracji wodnych roztworów barwników organicznych z dodatkiem substancji powierzchniowo czynnej i kationowego polielektrolitu. W badaniach wykorzystano płaskie membrany ultrafiltracyjne wykonane z regenerowanej celulozy i polietersulfonu. Membrany charakteryzowały się różnymi wartościami granicznej rozdzielczości (5 kDa, 10 kDa i 30 kDa). Proces ultrafiltracji przeprowadzono w przy ciśnieniach 0,1 MPa i 0,2 MPa w stosunku do roztworów anionowych barwników organicznych (oranżu metylowego, czerwieni indygo, czerni amidowej i czerni bezpośredniej) oraz roztworów barwników z dodatkiem surfaktantu - dodecylosiarczanu sodu (SDS) i kationowego polielektrolitu Magnofloc LT 22S. Stężenie barwników i SDS w roztworach wodnych wynosiło 100 g/m3, zaś polielektrolitu - 0,5 g/m3. Stwierdzono, że obecność kationowego polielektrolitu, jako substancji kompleksującej, przyczyniła się do polepszenia właściwości separacyjnych membran ultrafiltracyjnych (zwłaszcza polietersulfonowych) w stosunku do anionowych barwników organicznych i anionowej substancji powierzchniowo czynnej (SDS). Obecność kationowego polielektrolitu zarówno w roztworach zawierających anionowe barwniki organiczne jak i w roztworach barwników z anionową substancją powierzchniowo czynną spowodowała zmniejszenie wydajności membran ultrafiltracyjnych, zwłaszcza o umiarkowanej hydrofilowości. Przyczyną tego zjawiska było blokowanie struktury membran przez makrocząsteczkowe kompleksy typu polielektrolit-barwnik (SDS). Zjawisko to było tym bardziej widoczne, im większa była graniczna rozdzielczość membran.

EN

The effect of a cationic polyelectrolyte on the efficiency of dye and surfactant solution treatment by ultrafiltration was assessed. Flat UF membranes made of regenerated cellulose and polyethersulfone characterized by different cut-off values (5, 10, and 30 kDa) were used in the experiments. The UF process involved a pressure of 0.1 and 0.2 MPa. Permeation measurements were carried out with aqueous solutions of different anionic dyes (Methyl Orange, Indigo Carmine, Amido Black, and Direct Black) and dye solutions containing an anionic surfactant, sodium dodecyl sulphate (SDS), and/or a cationic polyelectrolyte, Magnofloc LT 22S. Dye and surfactant concentration in the experimental solutions amounted to 100 g/m3, whereas polyelectrolyte concentration was equal to 0.5 g/m3. It was found that when a cationic polyelectrolyte was present in the dye solutions or in the aqueous mixtures of an anionic dye and an anionic surfactant, this was concomitant with a decrease in membrane permeability and an increase in dye and surfactant retention (especially for polyethersulfone membranes). The observed effects can be attributed to the formation of intermolecular complexes of polycations with dye and surfactant particles. These polyelectrolyte complexes can cause membrane fouling, which is more pronounced for membranes of higher cut-off values and moderate hydrophilicity.

6

Usuwanie barwników organicznych z roztworów wodnych w procesie ultrafiltracji w obecności anionowej substancji powierzchniowo czynnej

Majewska-Nowak K.

Ochrona Środowiska

|

2006

|

R. 28, nr 3

15-24

PL

Określono wydajność i skuteczność procesu ultrafiltracji wodnych roztworów barwników organicznych z dodatkiem substancji powierzchniowo czynnej. W badaniach wykorzystano płaskie membrany ultrafiltracyjne wykonane z różnych polimerów (octan celulozy, regenerowana celuloza, polisulfon, polietersulfon i poliamid), charakteryzujące się różnymi wartościami granicznej rozdzielczości (cut-off), tj. 1 kDa, 5 kDa, 10 kDa i 30 kDa. Proces ultrafiltracji przeprowadzono w zakresie ciśnień od 0,05 MPa do 0,2 MPa w stosunku do roztworów anionowych barwników organicznych (oranż metylowy, czerwień indygo, czerń amidowa, żółcień tytanowa i czerń bezpośrednia) oraz roztworów barwników z dodatkiem surfaktantu (dodecylosiarczan sodu - SDS). Stężenie barwników i SDS w roztworach wodnych wynosiło 100 g/m3. Stwierdzono, że w wypadku membran o umiarkowanym stopniu hydrofilowości obecność SDS w roztworze przyczyniła się do obniżenia przepuszczalności membran i polepszenia efektu separacji barwników, natomiast w wypadku membran wybitnie hydrofilowych stwierdzono zjawisko odwrotne - dodanie anionowego związku powierzchniowo czynnego do roztworu anionowego barwnika spowodowało poprawę właściwości transportowych i niewielkie obniżenie skuteczności zatrzymywania barwników.

EN

The effect of an anionic surfactant on the efficiency of dye solution treatment by ultrafiltration was assessed. Flat UF membranes made of various polymers (cellulose acetate, regenerated cellulose, polysulfone, polyethersulfone, and polyamide) and characterized by different cut-off values (1, 5, 10, and 30 kDa) were used in the experiments. The UF process involved a pressure of 0.05, 0.1, 0.15, and 0.2 MPa. Permeation measurements were carried out with aqueous solutions of different anionic dyes (methyl orange, indigo carmine, amido black, titan yellow, and direct black) and dye solutions containing an anionic surfactant - sodium dodecyl sulfate (SDS). Dye and surfactant concentration in the experimental solutions amounted to 100 g/m3. It was found that when a surfactant was present in the dye solutions, this was concomitant with a decrease in membrane permeability and an increase in dye retention for membranes of moderate hydrophilicity. In the case of high-hydrophilic membranes, an opposite phenomenon was observed - the dosage of an anionic surface active agent into dye solutions brought about an improvement in transport properties and a slight deterioration in dye retention.

7

Studies on interactions between sodium dodecyl sulfate (SDS) and poly(ethylene glycol) (PEG)

Grębosz M., Nowakowska M.

Zeszyty Naukowe. Chemia / Politechnika Śląska

|

2001

|

z. 146

169-172

EN

The aggregation of sodium dodecyl sulfate (SDS) in aqueous solution containing poly(ethylene glycol) (PEG) has been investigated by different experimental techniques such as conductivity, surface tension and fluorescence. The critical micelle concentration (cmc) of SDS, the critical aggregate concentration of SDS on the polymer strands (cac) as well as the concentration at which the polymer becomes saturated with surfactant (c2) have been determined. The fluorescence methods have been shown to be more sensitive that the other physicochemical methods such as conductivity and surface tension measurements.

8

Kinetyka zwilżania warstw rozdrobnionych materiałów węglowych wodnymi roztworami dodecylosiarczanu sodu

Neffe S., Mizerski A.

Przemysł Chemiczny

|

2001

|

T. 80, nr 2

56-61