Rufus K. Guthrie

The influence of coal ash and thermal discharges upon the distribution and bioaccumulation of aquatic invertebrates

The distribution, density and uptake of twenty elements by aquatic invertebrates inhabiting a drainage system, that received excessive coal ash effluent (275 JTU of turbidity) at one end and thermal loading (44.5°C) at the other end, was studied for 15 months. The ash settling basin filled during the first eight months of sampling which resulted in the release of ash effluent directly into the receiving system. Density of invertebrates was lowest in the 300 m stream between the ash basin and swamp and highest 1200 m beyond the stream-swamp confluence where ash influence was minimal. Invertebrate density was lowest in the stations where turbidity from ash effluent was greatest. The most tolerant invertebrates to coal ash stress were odonates (Libellula sp. and Enallagma sp.), crayfish (Procambarus sp.), amphipods (Gammarus sp.) and gastropods (Physa. sp.), and midges (Chironomidae) when the basin was filling. During the period of ash overflow, all groups were either reduced in numbers or absent. In the thermally stressed station, Libellula sp. was the predominant invertebrate sampled when water temperature ranged from 25.5–45.5°C (257-1=28.7°C) all aquatic invertebrates were limited in numbers and density when temperature exceeded the lower and upper ranges of 10.0–38.0°C.

Cycling of elements in duckweed (Lemna perpusilla) in an ash settling basin and swamp drainage system

Abstract Duckweed ( Lemna perpusilla Torrey), inhabiting a stream-swamp drainage system that received high quantities of coal ash or thermal discharges from a fossil fuel power plant, was the only abundantly occurring macrophyte. For a period of 1 yr, accumulations of 22 elements in components of this system (water, sediments and duckweed) were determined at six stations using neutron activation analysis. Abiotic processes (e.g. settling, solution) were important in cycling some elements including heavy metals, while some potentially toxic elements (e.g. Hg and Se) were bioconcentrated by duckweed. In those stations where ash influence was greater in water and sediments, elemental uptake by duckweed was also higher. Approximately 1200 m 2 of swamp area was necessary to facilitate the removal of most ash influence. The use of duckweed as food may be a potential source of bioaccumulation or biomagnification of toxic elements by migratory wildfowl that frequent ash-impacted drainage systems.

Sorption of organics by Selenastrum capricornutum

Abstract The sorption of eight organic compounds by a representative green alga, Selenastrum capricornutum , was determined by gas-liquid chromatography using a series of linear model experiments. The log 10 bioconcentration factors (BCF), defined as the ratio of the concentration on in the algae to the concentration in the aqueous medium, are as follows: benzene, 3.32; toluene, 3.18; chlorobenzene, 3.69; 1,2-dichlorobenzene, 4.17; naphthalene, 4.10; phenanthrene, 4.38; di- n -butylphthalate, 4.36 and pyrene, 4.56. The relation of log 10 BCF correlation with log 10 octanol-water partition coefficient was determined as log 10 BCF = 0.46 log 10 P + 2.36.

The uptake of chemical elements from coal ash and settling basin effluent by primary producers II. Relation between concentrations in ash deposits and tissues of grasses growing on the ash

Abstract A number of reports of biomagnification of trace metals by plants indicate that elements are selectively concentrated within certain tissues when plants grow on coal ash. This study determined the uptake by, and tissue bioaccumulation of, 15 chemical elements within broom sedge and nut grass growing in the drainage system of a coal ash basin. Biomagnification of these elements by the grasses was compared to concentrations of these elements found in duckweed within the same system. Aluminium, arsenic, barium, cadmium, cobalt, chromium, copper, iron, mercury, manganese, molybdenum, selenium, strontium, titanium, and zinc were measured by neutron activation analysis in roots, stems, leaves and fruit of the grasses which grew in sediments within the effluent. Mercury and zinc were biomagnified in both grasses and duckweed to a level exceeding the concentration in sediment. All elements were biomagnified above the water concentration in all parts of the plants. Bioaccumulation of elements in the leaves and fruit of these plants provides a concentrated source of potentially toxic chemical elements for passage to animals which may consume these plants. The mechanisms of movement of potentially toxic elements from coal ash or water into food webs need additional study as utilization of coal is increased.

Aquatic bacterial populations and heavy metals—I. Composition of aquatic bacteria in the presence of copper and mercury salts

Abstract The effects of addition of copper (in copper sulfate) and mercury (in mercuric chloride) on the naturally occurring bacterial populations of two aquatic systems were studied. Water from each system, one brackish and one fresh water, was brought into the laboratory, and after one week stabilization period at room temperature was treated with metals. The impact of the elements was evaluated by comparing total colony forming units (TCFU), percentages of chromagenic organisms, and numbers of different colony types (diversity) in the laboratory system control with these parameters after additions of Cu and Hg. After stabilization, control (untreated) systems maintained stable TCFU counts throughout the 14-day test period. When either metal was added, an increase in TCFU occurred, a reduction in diversity was noted, and the percentage chromagens in the population varied. Similar results were observed when the elements were added simultaneously to a single system. These results indicate that heavy metal addition reduces bacterial community stability by the reduction in diversity coincident with increased TCFU of surviving organisms.

Mode of elemental dissipation from ash basin effluent

The dissipation of chemical elements from ash basin effluent was determined by use of neutron activation analysis of sediment, water, plant, invertebrate, and vertebrate samples taken from successive sites through the drainage system. Samples were tested for concentrations of 40 elements for a 12 mo period. Three different modes of dissipation were found. The major mechanism for removal of chemical elements from effluent was sedimentation into the benthic sediment. All biota had greater concentrations of chemicals than did water, with invertebrates having slightly higher levels than did plants and vertebrates. Ten elements were more concentrated in at least one biotic group than in the sediment. Concentrations of six elements in the drainage system exceeded the EPA recommended limits for surface waters. The observed modes of dissipation in this aquatic system emphasize the necessity for stable biotic communities present to permit cycling of chemical elements.

The uptake of chemical elements from coal ash and settling basin effluent by primary producers I. Relative concentrations in predominant plants

Chemical elements are released to the surface waters in large concentrations from coal ash, when ash is sluiced from the plant to a settling basin, or disposed on land surfaces. The role of primary producers growing in the drainage system receiving ash basin effluent, in removal or cycling of chemical elements from coal ash, has been investigated. Aquatic plants in the drainage system were collected and analyzed by neutron activation to determine concentrations of 23 chemical elements present in the coal ash effluent. The predominant aquatic producers present were Lemna perpusilla (duckweed), Typha Latifolia (cattail), Pontederia sp., Taxodium distichum (bald cypress), and the algae Oscillatoria sp. and Hydrodictyon sp. Leaves were collected from cattail, cypress and Pontederia sp., and the entire plants were collected from duckweed, Oscillatoria sp. and Hydrodictyon for analysis. Analysis of concentrations showed that duckweed, cattail, Oscillatoria sp. and Hydrodictyon sp. were the most efficient biomagnifiers of the 23 chemical elements. All elements were concentrated by the majority of the plants present relative to the concentration of the elements in the water in which the plants grew. This biomagnification of chemicals appears to be an important mechanism for removal of these elements from the drainage system water.

Aquatic bacterial populations and heavy metals—II. Influence of chemical content of aquatic environments on bacterial uptake of chemical elements

Abstract Bacterial populations from three aquatic sources (a coal ash basin, a brackish lake and a fresh water lake) were isolated, identified and tested for chemical element uptake under varying conditions. Elemental analysis was made by neutron activation. Increased concentrations of copper and/or mercury in the water affected the uptake of other elements in that overall concentrations of heavy metals was generally increased at 25°C while that of active metals and the halogens was decreased in brackish water (salinity 9 parts/10 3 ). Light metals were less affected. These effects were less pronounced in ash basin water and fresh water. Results indicate that elemental uptake by bacteria is affected by the particular combinations of chemical elements in an aquatic source.

Recovery of aquatic bacterial populations in a stream after cessation of chemical pollution

Tims Branch was studied for 1 yr to determine the effects of an annual loading of about 229 900 kg of various chemicals on the bacterial populations of a small fast flowing stream. The 10 yr discharge of chemical waste to this stream was terminated in 1973 and a 2 yr study of the streams recovery was begun. Upper Three Runs, an adjacent nonpolluted stream, was used as a control. Total culturable bacterial counts, per cent chromagenic bacteria and diversity were used as indices of recovery. Plate count agar was used for culturing aquatic bacteria present in both systems.Diversity in both systems was more affected by seasonal temperatures than the presence of chemical pollution. Mean total counts dropped from 187 × 103 in the polluted stream to approximate those of the control stream (170 × 103) following cessation of pollution. In the chemically affected stream, per cent chromagens increased from 15% during pollution to 25% approximately 1 yr after pollution was stopped. The latter percentage was comparable to that of the control stream (28%) during the period of study.

The effects of coal ash basin effluent and thermal loading on bacterial populations of flowing streams

Abstract Water quality parameters and elemental concentrations were studied for a period of one year in an ash basin drainage system. Measurements were made in streams heated by thermal discharge from an electric power plant and in a non-polluted reference stream. Water samples from four stations were cultured for total culturable heterotrophic bacteria in the water column, number of chromagenic colonies and total number of different colony types (diversity). Both thermal loading and large concentrations of chemical elements from the coal ash basin reduced diversity and percentage chromagens, although increasing total culturable bacteria. Temperature appeared to have a greater effect on community stability characteristics than did increased elemental concentration on the naturally-occurring bacterial populations in these systems.