| The wastewaters from oil shale retorting operations are complex mixtures of hydrophobic and hydrophilic organic solutes, inorganic salts, and trace elements. Following adsorbent separations of the organic constituents, measurements of dissolved organic carbon showed the proportions of acid, base and neutral subfractions that comprise the hydrophobic and hydrophilic solutes are very different for three different processes and sources of oil shale wastewaters. The organic compounds that have been identified by high resolution fused silica capillary chromatography included phenol, ortho-, meta-, and paraphenol, alkyl substituted phenols, n-C(,6)-C(,12) carboxylic acids, methylpyridines, dimethylpyridines, trimethylpyridines, aniline, substituted anilines, quinoline, isoquinoline, methyl-, and dimethyl-substituted quinolines. The use of fused silica capillary columns provided separations with high resolution and excellent peak shapes for polar compounds like underivatized carboxylic acids and the aromatic amines. Many of the organic compounds identified are good complexing ligands. Independent measurements of the abilities of the compounds in the oil shale wastewaters to form complexes with a model cation, Cu(II), were made. The complexing ability of the three wastewaters does not correlate with the total dissolved organic carbon concentration, but does compare well with the dissolved organic carbon concentration of the hydrophobic and hydrophilic base subfractions of the wastewaters. The complexing ability of the wastewaters decreases in the order, above-ground retort is much greater than the true in-situ, which is greater than the modified in-situ. The complexing ligands are also distributed by size, as demonstrated by a gel chromatography measurements of the constituents of the true in-situ retort water.; Leaching studies using wastewater and retorted shale from an above-ground process indicated that arsenic can be removed effectively from the wastewater by percolating it through the retorted shale. The retorted shale was also effective in reducing color and odor from the retort waters obtained from true in-situ and modified in-situ operations. Selenium, initially present at relatively high concentrations in the wastewater from an above-ground process, was not adsorbed. Molybdenum was leached from the spent shale with all three wastewaters and with distilled, deionized water irrespective of the concentrations of organic compounds present.; Adsorbent separation, liquid-liquid extraction, and steam distillation provide class fractionations of the organic solutes in the wastewaters. Steam distillation produces extracts that are readily amenable to gas chromatography, while organic solvent concentrates from liquid-liquid extraction contain considerable amounts of non-volatile materials. Adsorption on polymeric material (XAD-8) and ion exchange resins allows the concentration of organic solutes from large volumes of water.; Size fractionation and ion exchange experiments indicated that the majority of trace elements are present in the wastewaters as small hydrated ions or as labile organic or inorganic complexes. |
