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Part A - Removal of Sorbates from Solid Surfaces Soil washing has been found to be an effective cleaning methodology. This study examines the feasibility and effectiveness of a water-miscible organic solvent – lactic acid as an alternative extraction medium for removing PCP from soils. Pentachlorophenol (PCP) is a chlorinated organic compound that has been found in soils at several contaminated sites. Mixed solvents containing water and a water miscible solvent have been found to be more effective in extracting organic contaminants than the organic solvents alone. Our aim was to investigate solutions of lactic acid in water as potential alternatives to remove PCP from three model soils: montmorillonite, sediment from Caesar’s Creek, Ohio and this sediment ignited to remove organic matter. Solutions of different concentrations of lactic acid – water have proven effective in extracting PCP in different spiked soils. PCP extraction was found to be the maximum using a 25% concentration of lactic acid. Richer solutions did not yield a higher removal. The study included optimization of the concentration of lactic acid in water for maximum extraction efficiency and determination and comparison of the extraction of PCP with lactic acid for the three model soils. The effect of organic matter on the extraction was also studied. Initial experiments showed that 24 h was the optimum extraction time. High extraction efficiencies were obtained for montmorillonite (40-80%) and ignited soil (~90%). Caesar’s creek sediment exhibited low PCP extraction due to the presence of soil organic matter. Specific surface area of soil was also found to be an important factor affecting desorption of PCP. This ex-situ washing of soil with varying concentrations of lactic acid has been tested for maximum removal efficiency. Part B – Regeneration of Automotive Catalytic Converters In the regeneration of three way catalytic converters (TWCs), various solvents including biodegradable metal chelating agents, ionic liquids and organic acids were tested. The efficiency of novel environmentally friendly solvents in removing various contaminants such as P, Zn, Pb, Cu and S from commercial three way catalysts (TWC) has been investigated. In the first phase, the aim of our work was to investigate the biodegradable chelating agents [S, S]-ethylenediaminedisuccinic acid (EDDS), iminodisuccinic acid (IDSA), nitrilotriacetic acid (NTA) and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoborate, as potential alternatives to organic acids (citric, oxalic and acetic) and compare them with the same for effectiveness. Four samples of catalysts (from front and rear inlets) of two different TWC’s with different mileages and aged under completely different conditions were investigated. In both the samples, zinc removal was found to be dependent on its initial concentration present in the sample. The order of zinc removal was found to be IDSA>EDDS>IL>NTA. The catalysts were also characterized using various techniques – X-Ray diffraction (XRD), SEM (Scanning Electron Microscopy) and BET surface area measurements. In the second phase, the catalyst monolith was washed with only one solvent, EDDS. EDDS was selected of all those solvents tested because of its environmental benignity and its effectiveness in removing sulfur. SEM-EDS images at low magnification (50 μ) showed considerable difference in the surface after washing. However, our XRD results indicated that there was no removal of major poison compound phases. Correspondingly, little or no enhancement in Brunauer-Emmett-Teller (BET) surface area was observed between used and the washed samples.