Alkylpyridines in Surface Waters, Groundwaters, and Subsoils of a Drainage Located Adjacent to an Oil Shale Facility Robert G. Riley,’ Thomas R. Garland, Kazumi Shiosaki, Dale C. Mann, and Raymond E. Wildung Environmental Chemistry Section, Pacific Northwest Laboratory, Battelle Memorial Institute, P.O. Box 999, Richland, Washington 99352
Soil extracts, surface waters, and groundwaters were analyzed for the presence of water-soluble organic compounds in a drainage located adjacent to the retorted shale disposal pile at the Department of Energy Anvil Points Oil Shale Facility, Rifle, CO. The c 3 - C ~alkylpyridines were positively identified in water from one of several alluvial wells, and in a surface seep. Surface waters of the stream below the seep contained alkylpyridines but in lower concentration. Alkylpyridines were detected in a moist subsoil sampled adjacent to the well, in retort water, and in aqueous extracts of shale oil. They were not detected in aqueous extracts of raw shale, retorted shale, or Prudhoe Bay crude oil. The absence of the alkylpyridines in a petroleum suggests that the compounds may be unique to shale oils, perhaps allowing their use as diagnostic indicators of water in contact with shale oils at sites of oil shale production and processing. Introduction
Because of the uncertain status of current world petroleum prices and supplies, emphasis is being placed in the United States on the development of processes for the production of synthetic fuels from oil shale and coal. The above-ground oil shale retorting processes produce liquid and solid wastes that, in many respects, are unique to the industry ( I ) . Current protocols call for the disposal of retorted shale to the ground, possibly in association with retort water used for compaction and dust control. Recent investigations (2-4) have indicated that a high percentage of organic compounds comprising retort water and retorted shale are polar, accounting for their high water solubility. Mono- and dibasic organic acids, a class of compounds that fit this category, have been identified in retort water, but these identified compounds account for only 0.4% of the soluble organic carbon (2). Compounds with relatively low affinity for retorted shale, with sufficient leaching, could subsequently enter surface water and groundwater adjacent to oil shale operations (5-10). There is a need to further define the composition of retort water as identification of organic compounds in leachates from retorted shale and codisposed materials early in the development of commercial production processes will allow development of control measures necessary to minimize environmental and human health effects resulting from waste disposal. Studies were initiated a t the Department of Energy Anvil Points Oil Shale Facility a t Rifle, CO, in the spring of 1979 to evaluate the environmental fate of mobile residues from the wastes disposed during shale oil production. This site has been utilized for development of oil shale mining and production processes since the 1940s. The stream and drainage basin characteristics have been described ( 1 1 ) . Solid wastes, principally retorted shale and raw shale fines, produced by several experimental processes have been disposed to the West Sharrard drainage adjacent to the facility. Furthermore, retort water and shale oil have been stored periodically on the site for a number of years. Current investigations are directed toward determination of the concentration of water-soluble organic compounds in materials disposed of or stored at the site and in surface waters, groundwaters, and subsoils above and below the site. Continuing studies are underway to aid in defining the source and hydrologic transport of water-soluble
compounds which may result from nearly 40 yr of operations and waste disposal. Experimental Section
Sample Collection. To identify changes in water composition, we collected samples of surface waters, alluvial groundwaters (well waters), and seeps from above and below the disposal location in West Sharrard drainage for organic chemical analysis. Water samples from West Sharrard stream and several alluvial wells and a seep located adjacent to the stream were collected in Teflon bottles in May 1979. The samples were immediately frozen (-20 “C) and transported to the laboratory for chemical analysis. Samples of shale oil, retorted shale (120 "C) and for sampling a t elevated temperatures, Tenax-GC has been recommended because of its greater thermal stability compared to XAD-2 (7). Nitrogen oxides present in fossil fuel combustion products may react with sampling media. The decomposition of Tenax-GC when sampling stack gases has been attributed to reaction with the nitrogen oxides ( 8 ) . Neher and Jones (9) reported the formation of 2,6-diphenyl-p-quinone (DPQ) as a result of reactions of Tenax-GC with nitric oxide, higher oxides of nitragen, or nitric acid present in stack gases. Chromosorb 102, which is a styrenedivinylbenzene polymer very similar to XAD-2, has been found to react with NO2 and oxygen at elevated temperatures (10,ll). However, reactions of nitrogen oxides with XAD-2 have not been reported. Therefore, the decomposition products of Tenax-GC and XAD-2 formed by reaction with nitrogen dioxide and nitric oxide were examined. The results of these investigations indicated that both adsorbents decomposed but that the products from Tenax-GC did not interfere with gas-chromatographic analysis of vapor-phase organics which elute before 1,2-benzofluorene (bp, 398 OC). The Salmonella mutagenicity assay has been used to aid in identifying environmental chemicals causing mutations and cancer (12-14). Extracts of samples of fossil fuel combustion products have been found to be mutagenic in the Salmonella 0013-936X/81/0915-0701$01.25/0 @ 1981 American Chemical Society
mutagenicity assay (15,16).This bioassay is useful for identifying mutagenic samples of combustion products. Pellizarri et al. (17) recommend field sampling of pollutants as part of the evaluation of adsorbent samplers. The evaluation of the collection characteristics of Tenax-GC were undertaken by sampling the flue gases from combustion of Paraho oil shale. Tenax-GC has been used in an uncooled adsorbent trap for stack temperatures from ambient to 50 "C (18). Three adsorbent samplers were placed in series to ensure complete sample collection. Analysis of these samples revealed that vapor-phase organics were present with large quantities of Tenax-GC decomposition products. Experimental Section
Materials. Tenax-GC, a polymer of 2,6-diphenyl-p-phenylene oxide 60/80 mesh (Figure 1)(Enka N.V., the Netherlands), and Amberlite XAD-2, a styrene-divinylbenzene polymer 20/50 mesh (Figure 1) (Rohm and Hass Co.) were used in the studies. The Tenax-GC was Soxhlet extracted with glass-distilled n-pentane for 24 h and dried in an oven at 110 OC before use. The XAD-2 was Soxhlet extracted with glassdistilled dichloromethane to achieve less than 10 yg of extractable residue per gram of polymer for 24-h extraction and then dried in an oven at 110 OC before use. Tenax-GC is soluble in polar solvents; therefore, an aliphatic hydrocarbon (n-pentane) is used to extract traces of residues before use. The XAD-2 contains more residues than Tenax-GC, and XAD-2 can be extracted with polar solvents to clean it before use. Sampling. The adsorbent was packed in brass tubes (Figure 2, 15-cm long, 2.5-cm i.d.1 which were placed in series. Stainless-steel screens a t each end of the tube kept the adsorbent in place. A 47-mm glass-fiber filter was mounted in a filter holder for the studies with nitrogen oxides (Figure 2 ) . A silver-membrane filter was used as the filter for sampling oil shale combustion flue gases from a fluidized bed combustor (FBC). The filters were used to collect the particles. The experimental conditions for the study of the decomposition products from Tenax and XAD-2 are given in Table I. The adsorbents were Soxhlet extracted for 24-h by using n-pentane for Tenax-GC and dichloromethane or n-pentane for XAD-2. The sampling of organics in (FBC) combustion effluents has been previously described (19-21). Generally, 10 L/min of diluted stack gases was sampled from 36 t o 103 min. The NO, concentration of the undiluted effluent ranged from 460 to 810 ppm. A second and a third sampler were placed behind the first to collect any organics that pass through the first adsorbent sampler. Sample Analysis. Qualitative identifications of compounds were made by using a Finnigan Model 4023 gas chromatograph-mass spectrometer (GC-MS) with an INCOS data Volume 15, Number 6, June 1981 701
