Laboratory analytical results of 22 sets of hydrophobic adsorbent coils containing surface soil-vapor and two soil samples collected by conventional intrusive method from each boring location at two active dry cleaning facilities in the State of Illinois, U.S.A, were presented to evaluate the performance of soil-vapor survey. The most critical factor to determine the effectiveness of soil-vapor survey is the distance from the soil-vapor sampling device to the actual contamination, which is a function of soil porosity, permeability, primary lithology, and other geological and hydrogeological site-specific parameters. Also this factor can be affected by the history of contaminant-generating operations. The laboratory analytical results in this study showed longer drycleaning operation history (i.e., 50 years) and presence of fine sand at the beneath Site B allow the contaminants to migrate farther and deeper over a fixed time compared to Site A(i.e., 35 years and silty clay) so that the soil-vapor survey is not likely the most effective environmental site investigation method alone for Site B. However, for Site A, the soil-vapor survey successfully screened the site to identify the location reporting the highest soil concentration of chlorinated solvents.
A magenta azomethine dye(D) was synthesized from the reaction of 3-methyl-1-phenyl-2-pyrazoline-5-one with N,N-diethyl-1,4-phenylenediamine. The magenta azomethine dye was identified on the basis of elemental analysis, 13C-NMR, infrared, and GC/MS studies. The magenta azomethine dye was decomposed in a basic solution. Rate constants of the fading reaction of magenta azomethine dye in ethanol-water solvent were measured spectrophotometrically at 540 nm. Reaction rate was increased with the increase of [OH-] and [H2O] in the region of [H2O]= 11~40 M. The reaction was governed by the following rate law.
-d[D]/dt = {ko + kOH[OH-][H2O]}[D]
A possible mechanism consistent with the empirical rate law has been proposed.
For the destruction of toxic chlorinated organic compounds, this study proposes improved supercritical water oxidation method (multistep oxidation) using sodium nitrate as an oxidizer. This method solves the problems involved in the existing supercritical water oxidation method. Multistep oxidation means that NaNO3 is oxidized to N2 via NaNO2 and NO. Toxic and hard to destroy organic substances like para-dichlorobenzen(4-DCBz), polychlorinate biphenyl(PCB) ware oxidized to non toxic substances in a condition, in which rapid pressure and temperature rise is restrained as much as possible. 4-dichlorobenzene(4-DCBz) and Polychlorinate biphenyl(PCB) in condition(450℃, pw=0.25g/cm3, 30min) Was discomposed perfectly.
N,N-bis(2-salicylaldehyde)dipropylenetriamine(5-Hsaldipn), N,N-bis(5-bromosalicyl-aldehyde) dipropylenetriamine (5-Brsaldipn), N,N-bis(5-chlorosalicylaldehyde)dipropylene-triamine(5-Clsaldipn), N,N-bis(2-hydroxy-5-methoxybenzaldehyde)dipropylenetriamine(5-OCH3saldipn) and N,N-bis (2-hydroxy-5-nitrobenzaldehyde)dipropylenetriamine (5-NO2saldipn) were synthesized and characterized by elemental analysis, infrared spectrometry, NMR spectrometry and mass spectrometry. Their proton dissociation constants were determined in 70% dioxane/30% water solution by potentiometric. Stability constants of the complexes between these ligands and the metal ions such as Cu(Ⅱ), Ni(Ⅱ) and Zn(Ⅱ) were measured in dimethyl sulfoxide by a polarographic method. Stability constants for the ligands were in the order of 5-OCH3 > 5-H > 5-Br > 5-Cl > 5-NO2saldipn. Enthalpy and entropy changes were obtained in negative values.
The thiophene or furan-containing hexadentate ligands 1,12-bis (2-theophene)-2,5,8,11-tetraazadodecane(Thiotrien ․4HCl) and 1,12-bis (2-furan)-2,5,8,11-tetraazadodecane(Furatrien․4HCl) were synthesized as their tetrahydrochloride salt and characterized by EA, IR, NMR, and Mass spectrum. Their protonation constants (logKnH) and stability constants (logKML) for Cd2+, Pb2+, Zn2+ and Cu2+ ions were determined in aqueous solution by potentiometry and compared with 1,12-bis(2-pyridyl)-2,5,8,11-tetra-azadodecane(Pytrien) of pyridyl-containing ligand. The effect stability constants of ligands and metal ion for removal of heavy metals in aqueous solution were described.
The new tridentate ligands of nitrogen doner atoms N,N-Bis(2-amino-ethyl)-benzyl-amine·2HCl(BABEA·2HCl) and 2,6-Bis(amino-methyl)-pyridien·2HCl(BAMP·2HCl) were synthesized as their dihydrochloride salts and characterized by EA, IR, Mass and NMR spectroscopy. The protonation constants of the ligands and stability constants for Cd2+, Pb2+, Zn2+and Cu2+ ions were determined by potentiometric titration in aqueous solutions and compared with those of analogous ligands. The effect stability constants of ligands and metal ions for removal of heavy metals in aqueous solution were described.
Attempts have been made to use Supercritical fluids for industrial purpose in a variety of fields and some of them, are already in practice. However, basic chemical properties of supercritical fluids have not been understood well.
The present paper presents the results of physicochemical studies on Supercritical fluids as well as the application of supercritical fluids to industry. The detail is as follows PCB and organic compounds.