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Quantities of polycyclic aromatic hydrocarbons (PAH), some of which are carcinogens, enter natural waters in effuents of coke production and other high-temperature industrial pyrolysis processes. Because of their low water solubilities. PAH compounds are generally considered to occur in particulate form in lakes and rivers. However, present studies of 14 C-anthracene adsorption by autoclaved yeast cells indicated that significant fractions of both dissolved and particulate forms of PAH may exist in natural waters. Quantities of anthracene adsorbed exceeded values for PAH adsorption onto mineral surfaces by more than an order of magnitude: suspended organic material may thus be more important than mineral particles in adsorption of PAH compounds. Adsorption was highly dependent upon the yeast cell concentration, and varied widely through the range of suspended organic solids normally encountered in natural waters. The heat of adsorption (5.2 kcal/mole) was characteristic of a physical adsorptive process. Because ecological effects and pathways of dissolved and particulate PAH may differ, adsorptive partitioning may be important in determining PAH hazards to higher organisms in aquatic food chains, and ultimately to man.

A numerical model was developed to predict dissolved aqueous concentrations of phenolic contaminants resulting from accidental spillage of a synthetic oil into a river. The model (termed SOPTRAN, for synthetic oil pollutant transport) simultaneously solves algorithms for processes of oil slick spreading, oil evaporation, phenolics dissolution, advection and dispersion using an implicit integrated compartment method. To test SOPTRAN, predictions were compared with measurements of phenolics dissolution into underlying water following application of a coal-liquefaction product to two 3.75 × 3.75 × 1 m ponds. The mean of measured concentrations during phenolics dissolution was 84% (coefficient of variation = 43%) of predicted values. With minimal calibration, SOPTRAN adequately described differential rates of dissolution of phenol and C1- to C4-alkylphenol isomer groups. The model was used to simulate a hypothetical 300-m3 (80,000-gal) accidental release of a coal liquid from a barge into a large navigable river under both instantaneous and noninstantaneous (i.e., leakage) spill scenarios.

Sixteen 67-liter freshwater microcosms were treated for 8 weeks with an unrefined coal-oil in amounts ranging from 0.03 to 7 ml per week. Phenols make up 95% of the water-soluble compounds in this oil, and dissolved phenol concentrations averaged < 0.01 mg L/sup -1/ in the lowest dose and 10 mg L/sup -1/ in the highest. The microcosms were severely damaged at the highest treatment level; macrophytes, zooplankton and insects were eliminated, and the ecosystems became anaerobic. Microcosms did not recover to pretreatment conditions within 5 months. At lower dosages there were temporary effects on ecosystem metabolism, water chemistry and community structure. The most sensitive indices, community respiration, production/respiration ratio, pH and cladoceran zooplankton numbers, were affected at phenol concentrations below the lowest observable effect concentration of a chronic Daphnia magna bioassay.

The environmental fate of constituent phenols of a coal-derived oil spilled intermittently on water was evaluated in aquatic microcosms. Phenols dissolved rapidly from the oil into the water, and initially accumulated with sequential oil additions. The major process removing phenols from the microcosms was microbial degradation-other processes were negligible in comparison. After phenols attained maximum concentrations in the first 28 days of the study, degradation rates exceeded input rates in all microcosms during the second 28 days the study and total phenol concentrations decreased. Significant differences were apparent in the rates of degradation of various alkylphenol isomers and isomer groups, but no compounds were observed to be refractory. Upon discontinuation of oil inputs at day 56, dissolved phenols disappeared within several weeks. Microcosm exposure history and the presence of other phenol isomers affected the rate of removal of individual isomers, complicating prediction of the rate of removal of individual toxicants.

To facilitate predictions of the transport and fate of contaminants at future coal conversion facilities, rates of microbial transformation of polycyclic aromatic hydrocarbons were measured in stream water and sediment samples collected in the vicinity of a coal-coking treated wastewater discharge from November 1977 through August 1979. Six radiolabeled polycyclic aromatic hydrocarbons were incubated with sediment and water samples; 14 CO 2 , cell-bound 14 C, and polar transformation products were isolated and quantified. Whereas 14 CO 2 and bound 14 C were major transformation products in sediment assays, soluble polar 14 C dominated transformation in water samples. Mean rate constants (measured at 20°C) in sediments collected downstream from the effluent outfall were 7.8 × 10 −2 h −1 (naphthalene), 1.6 × 10 −2 h −1 (anthracene), and 3.3 × 10 −3 h −1 [benz(a)anthracene], which corresponded to turnover times of 13, 62, and 300 h, respectively. No unequivocal evidence for transformation of benzo(a)pyrene or dibenz(a,h)anthracene was obtained. Only naphthalene and anthracene transformations were observed in water samples; rate constants were consistently 5- and 20-fold lower, respectively, than in the corresponding sediment samples. The measured rate constants for anthracene transformation in July 1978 sediment samples were not related to total heterotroph numbers. In late July 1978, the effluent was diverted from the primary study area; however, no differences were observed either in transformation rate constants or in the downstream/upstream sediment rate constant ratio. These results are consistent with the hypothesis that continuous inputs of polycyclic aromatic hydrocarbons result in an increased ability within a microbial community to utilize certain polycyclic aromatic hydrocarbons. However, because transformation rates remained elevated for more than 1 year after removal of the polycyclic aromatic hydrocarbon source, microbial communities may shift only slowly in response to changes in polycyclic aromatic hydrocarbon concentrations.

To facilitate development of a model for dissolution of toxic contaminants from synthetic coal liquids in the event of an accidental riverine spill, dissolution rates from oil films overlying water in a stirred laboratory extractor were measured by solvent partitioning and gas chromatography. Major water-soluble contaminants identified in five coal liquids were phenol, aniline and their C1–C3 alkylated derivatives. First-order rate constants for approach to equilibrium were related to the oil-water partition coefficient in an inverse nonlinear relationship; data agreed well with a two-film model developed and verified previously. Overall mass transfer coefficients varied nearly 103 from phenol to naphthalene in one oil. Oil-phase mass transfer coefficients were inversely related to oil viscosity. Results indicate that under riverine turbulence conditions in which spilled oil is not dispersed by mixing into the water column, phenols and anilines in coal liquids will dissolve far more rapidly than one- and two-ring aromatic hydrocarbons.

Four coal-derived oils, a No. 2 diesel fuel oil, and a petroleum crude oil were layered onto water in a closed, stirred vessel and were exposed to natural or artificial sunlight for periods up to 170h. Photooxidants which dissolved into the underlying water were quantified amperometrically. Concentrations of water-soluble photooxidants increased steadily beneath all coal liquids at 25% of the rate beneath diesel fuel; none were produced beneath irradiated crude petroleum. Characterisation of photooxidants by kinetics and thermodynamics of reaction with iodide indicated that hydrogen peroxide and organic hydroperoxides were produced under one coal liquid. Acute toxicities to Daphnia magna of the water before and after reduction of photooxidants with thiosulphate were consistent with these identifications. The results suggest that photooxidant production may enhance the toxicity of spilled coal liquids in rivers, particularly after the highly soluble phenols have been depleted from a floating oil film.

To facilitate determination of lipid content of freshwater invertebrates for bioaccumulation studies, the chloroform–methanol extraction procedure of Bligh and Dyer was modified for microquantitation. Following extraction, lipids were quantified by use of a micro-balance. Recoveries of representative neutral and polar lipids averaged 88.3% with a mean coefficient of variation of 8.6%. Tests with freshwater benthic and pelagic invertebrates demonstrated the applicability of the procedure to samples as small as several milligrams wet weight with a mean coefficient of variation of 11.6%.

Although the concentration of soluble organic phosphorus in lake water often exceeds that of orthophosphate severalfold, little is known of its composition. By using enzyme assays it was determined that up to 50 percent of the organic fraction is hydrolyzable by phytase. The enzymatically degradable material consists of both low and high molecular weight fractions.

Polycyclic aromatic hydrocarbons (PAH) constitute a series of compounds, some of which are potent carcinogens, which have been detected in natural waters throughout the world. Major sources are aqueous effluents from high-temperature industrial pyrolysis processes, including coke production (Andelman and Suess, 1970). Coal liquefaction, which may provide substantial quantities of synthetic fuel within 15 years, may also release PAH in wastewater streams (Guerin, 1975). Because PAH have been demonstrated to concentrate to high levels in tissues of aquatic organisms (Shimkin et al., 1951; Scaccini-Cicatelli, 1966; Stegeman and Teal, 1973), a potential exists for biomagnification within food webs to levels hazardous both to fish and to human consumers of aquatic organisms. Corner (1975) has suggested that uptake by filter-feeding organisms may constitute a major mechanism of entrance of PAH to aquatic food chains. In this laboratory, we have demonstrated the ability of several invertebrates to concentrate anthracene, a three-ring PAH compound, from both dissolved and particulate forms. In this paper we present further investigations of the kinetics of excretion and metabolic alteration of anthracene by a representative zooplankter (Daphnia pulex) to evaluate the effect of excretory processes on the potential for bioaccumulation of PAH compounds in aquatic organisms.

Acute toxicities of mixtures of resorcinol and 6-methylquinoline to Daphnia Magna (a representative zooplankter) were investigated to assist in assessing the potential effects of coal conversion effluents on aquatic biota. Results indicated that mixtures of resorcinol and 6-methylquinoline were less toxic than either pure compound tested alone. The data suggest that antagonism occurs when resorcinol is the major toxic component, while an infra-additive interaction occurs when 6-methylquinoline is the major toxic component. The work indicates that addition of fractional toxicities may produce substantial errors in prediction of toxicity of mixtures of non-homologous organic components. (CAJ)

To determine rates of microbial transformation of polycyclic aromatic hydrocarbons (PAH) in freshwater sediments, 14 C-labeled PAH were incubated with samples from both pristine and petroleum-contaminated streams. Evolved 14 CO 2 was trapped in KOH, unaltered PAH and polar metabolic intermediate fractions were quantitated after sediment extraction and column chromatography, and bound cellular 14 C was measured in sediment residues. Large fractions of 14 C were incorporated into microbial cellular material; therefore, measurement of rates of 14 CO 2 evolution alone would seriously underestimate transformation rates of [ 14 C]naphthalene and [ 14 C]anthracene. PAH compound turnover times in petroleum-contaminated sediment increased from 7.1 h for naphthalene to 400 h for anthracene, 10,000 h for benz(a)anthracene, and more than 30,000 h for benz(a)pyrene. Turnover times in uncontaminated stream sediment were 10 to 400 times greater than in contaminated samples, while absolute rates of PAH transformation (micrograms of PAH per gram of sediment per hour) were 3,000 to 125,000 times greater in contaminated sediment. The data indicate that four- and five-ring PAH compounds, several of which are carcinogenic, may persist even in sediments that have received chronic PAH inputs and that support microbial populations capable of transforming two- and three-ring PAH compounds.