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Student: D.N. Guo

Recovery and extraction of heavy metal ions using ionic liquid as

green solvent

International Journal of Modern Physics B Vol. 20, Nos. 25, 26 & 27 (2006) 4051-4056

MAS AMI KUMANO, TOMOKI YABUTANI and JUNKO MOTONAKA*

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Contents

Introduction1

Experimental2

Results and discussions3

Conclusions4

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Introduction

Organic solvents are useful for separation, extraction and synthesis. "Green Chemistry" has been advocated in engineering and science field.

In the concept of Green Chemistry, it is desirable to reduce consumption of conventional organic solvent for reduction of the environmental and human health risks.

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Introduction

They are molten salts composed of organic cations and various anions. Ionic liquids are in liquid form at room temperature and offer excellent potentials for alternative solvent.

They have unique features that are high ion conductivity, chemical stability, non-volatility and high thermal stability.

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Introduction

They have already been used in organic synthesis, solvent extraction, chromatography and electrochemistry such as chargeable buttery, fuel cell, capacity, light emission device and wet solar cell.

In this work, extraction of heavy metals in wastewater using ionic liquid as green solvent was examined. The effects of 8-HQ concentration, shaking time and volume ratio on the extraction efficiency were investigated.

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Experimental

ApparatusICP-AES, thermostat, pH meter, HPLC

MaterialsN,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium bis (trifluoromethansulfonyl) imide8-hydroxyquinoline(8-HQ), nitric acid, phosphoric acidHPLC-grade methanolPotassium dihydrogen phosphate

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Experimental

Sample

polypropylene tube

centrifuged

aqueous phase (add 2mol/l HNO3)

ionic liquid phase

ICP-AES

HPLC

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Experimental

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Results and discussions

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Results and discussions

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Results and discussions

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Results and discussions

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Results and discussions

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Conclusions

It was possible to obtain high extraction efficiency of heavy metal ions using ionic liquid with 8-HQ as metal chelating agent.

Extraction efficiency depended on the concentration of 8-HQ and its chelating stabilities to analyte.

Under the optimal condition, 1424 μg of heavy metal ions were recovered in the 100 μl of ionic liquid.

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Thank you for your attention