Development of a Sustainable Technology for the Extraction of Pesticides from Contaminated Surface Water by using Surface Active Ionic Liquid

It is known that current rates of agricultural production worldwide strongly depend on the use of pesticides. A pesticide product consists of two parts: active and inert ingredients. Active ingredients are chemicals which actually control the pest. Inert ingredients are primarily solvents and carriers that help deliver the active ingredients to the target pest. For water insoluble pesticide, such as preparing emulsifiable concentrate (EC) formulations, a large amounts of hazardous organic solvents will be introduced which are harmful to environment. EC formulations are used to solubilize the relatively non-volatile pesticide into a concentrated form containing a large fraction of volatile organic compounds (VOCs); they are also easily diluted with water for use in sprayer equipment. With increasing environmental awareness, the concept of green chemistry is now fully embraced by pesticides industry such as aggressive promotion of the use of more environmentally?friendly solvents and raw materials as well as the reduction of hazardous waste generation. Regulatory agencies intend to discourage the use of VOCs in pesticide products mitigate the VOC emissions. Numerous industries embrace the concept of green chemistry by encouraging the use of safer solvents and raw materials as well by reducing the generation of hazardous wastes. Among the neoteric solvents applicable in green technologies, ionic liquids (ILs) garner increasing attention for its negligible vapor pressure, excellent thermal stability, good extractability and selectivity for organic and inorganic compounds and recyclability. In addition, ILs are green, less toxic and more effective at lower concentrations, so as to improve wastewater quality. Water immiscible ILs with large, highly charge-delocalized anion easily can form biphasic systems with water and have been used for liquid phase micro-extraction of different nonpolar, hydrophobic organic compounds. Contrary, water miscible ILs with small and low charge-delocalized anion are able to form aqueous biphasic systems (ABS) due to a salting out effect upon addition of inorganic or organic salts, polymers, carbohydrates. The purpose of this work to develop sustainable approach for the extraction of selected pesticides of different polarity (acetamiprid, imidaclopride, simazine, linuron and tebufenozide) applying ABS based on ILs. The targeted pesticides were chosen as a model system to cover wide range of polarity from nonpolar to polar e.g. from hydrophobic to hydrophilic compounds. The influence of various ILs cation and anion on the partitioning and extraction efficiency of the pesticide would be studied investigated using the bio based ILs. Additionally, Conductor-like Screening Model for Realistic Solvation (COSMO-RS), a quantum approach would be applied to describe main interactions of polar pesticides and the ILs in the ABSs which are important for their successful extraction. The project also appraises current developments and future prospects of proposed ILs. This proposal involves a multi-disciplinary team from Qatar University and the Sultan Qaboos University (SQU), Oman.