A new approach for the extraction of organic compounds from different types of contaminated waters and sewage sludge

Liquid-liquid extraction LLE, is one of the oldest separation techniques, with most used applications in analytical chemistry especially for contaminated waters. LLE extraction involves different distribution of chemical species between two immiscible liquid phases, depending on their physical-chemical properties. Other different extraction techniques used to remove organic compounds from contaminated water and sewage sludge can be enumerated: the following techniques: continuous liquid-liquid extraction, solid-liquid extraction, solid phase microextraction, accelerated solvent extraction, ultrasonic extraction and some correlated techniques. A new extraction technique partially based on the principle of continuous extraction with recirculation of the sample through a layer of solvent or mixture of solvents was developed in our analytical laboratory. The extraction method was verified by comparison with three classical techniques: liquid-liquid extraction, solid-liquid and ultrasonic extraction. The results have demonstrated the performance of this new extraction technique consisting in reduced time and costs for sample preparation and especially increased efficiency for extraction of organic compounds from sewage sludge.