Treatment of Soil Contaminated with Ionic Liquids

• Main Author: Siti Nurain Roseli, Siti Nurain
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi Petronas 2010
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/1183/1/SITI_NURAIN_ROSELI.pdf; http://utpedia.utp.edu.my/1183/

Ionic liquids (ILs) are molten salts consist of positive and negative ions. It is being utilized in many applications of industry especially as main solvents in green chemistry. This is mainly for reason that ILs have properties of non flammable chemical due to its low vapor pressure less toxic than conventional organic solvents. However, toxicity of these compounds is still under investigation by many scientists. In case these compounds released into environment especially soils and sea, it may cause bad impacts. Current investigations showed that ILs may become toxic toward other organisms. Thus, the aim of this work is to investigate the effectiveness of solvent washing method to treat ILs that contaminate in soils. In this study, soil is collected from dry area in Perak. The pH of soil is measured equal to 5.719. The acidity of soil may influence the leaching or movement of ionic liquid. This is because acidity of soil also indicates the total organic matter content in soil which influences the interaction between ionic liquids cations and organic matter of soil. The soil is then dried using oven and aliquot amount of ionic liquid is added into the soil. Then, the mixture is left for 72 hours for equal distribution of contaminant in the soil. Two ionic liquids are used in this experiments which are 1- butyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium tetraflouroborate. Methanol is used as the solvent to wash the soil. Few variables are being manipulated which are amount of methanol, concentration of contaminant and speed of shaking during treatment. After manual contamination procedure, soil is then washed with different amount of methanol and shaken for 2 hours at different shaking speed. Amount of methanol added are 60ml, 70ml, 80ml, 90ml, 100ml, 110ml, 120ml, and 130ml while shaking speeds are 150rpm, 160rpm, 170rpm, 180rpm, 190rpm, 200rpm, 210rpm and 220rpm. At the end of the experiments, washed soil is filtered and liquid sample is analyzed using HPLC analyzer to get final concentration of ionic liquid left in soil. Results obtained show that removal of ILs from soil are enhanced with the increase of methanol added during washing and increase of shaking speed of water bath shaker.