Comparative study between liquid–liquid extraction and bulk liquid membrane for the removal and recovery of methylene blue from wastewater

AbstractStudies on liquid-liquid extraction and bulk liquid membrane (BLM) technique-based metal ion separation by a previously published Pb2+-selective acridono-18-crown-6 ether selector molecule were performed. The effects of the stirring speed, the quality of apolar organic membrane, the counterions of Pb2+, the pH of the aqueous phase, the concentration of the source phase, the concentration of the carrier in the BLM and the temperature on the Pb2+-separation were investigated. Moreover, the effects of the competitive inhibition due to the presence of Ag+, Ca2+, Co2+, Cu2+, K+, Mg2+, Na+ and Zn2+ as competing ions in a multicomponent aqueous source phase of different ion-concentrations were also studied. After a proper dilution of the multicomponent aqueous source phase, excellent Pb2+-selectivity was achieved without a significant reduction in the efficiency compared to the liquid membrane transport of single-component systems. Based on the BLM-cell studies the applied selector molecule proved to be suitable for the development of liquid membrane-based Pb2+-selective separation methods, which can be greatly aided by the analysis of the effects on the separation and by the optimization of the parameters of the process discussed here.

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Treatment of cyanide wastewater by bulk liquid membrane using tricaprylamine as a carrier

Water Science & Technology ◽

10.2166/wst.2016.136 ◽

2016 ◽

Vol 73 (12) ◽

pp. 2888-2895 ◽

Cited By ~ 4

Author(s):

Guoping Li ◽

Juanqin Xue ◽

Nina Liu ◽

Lihua Yu

Keyword(s):

Organic Phase ◽

Liquid Membrane ◽

Removal Rate ◽

Feed Solution ◽

Bulk Liquid ◽

Complexation Reaction ◽

Bulk Liquid Membrane ◽

Reaction Conditions ◽

Optimal Reaction ◽

Removal And Recovery

Abstract The transport of cyanide from wastewater through a bulk liquid membrane (BLM) containing tricaprylamine (TOA) as a carrier was studied. The effect of cyanide concentration in the feed solution, TOA concentration in the organic phase, the stirring speed, NaOH concentration in the stripping solution and temperature on cyanide transport was determined through BLM. Mass transfer of cyanide through BLM was analyzed by following the kinetic laws of two consecutive irreversible first-order reactions, and the kinetic parameters (k1, k2, Rmmax, tmax, Jamax, Jdmax) were also calculated. Apparently, increase in membrane entrance (k1) and exit rate (k2) constants was accompanied by a rise in temperature. The values of activation energies were obtained as 35.6 kJ/mol and 18.2 kJ/mol for removal and recovery, respectively. These values showed that both removal and recovery steps in cyanide transport is controlled by the rate of the chemical complexation reaction. The optimal reaction conditions were determined by BLM using trioctylamine as the carrier: feed phase: pH 4, carrier TOA possession ratio in organic phase: 2% (V/V), stripping phase concentration of NaOH: 1% (W/V), reaction time: 60 min, stirring speed: 250 r/min. Under the above conditions, the removal rate was up to 92.96%. The experiments demonstrated that TOA was a good carrier for cyanide transport through BLM in this study.

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