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The effects of sewage sludge, lime, and gypsum on the revegetation of acidic coal refuse material were studied at a Fulton County, IL, land reclamation site. Treatments consisted of a control, 542 dry Mg ha−1 anaerobically digested sewage sludge, 89.6 Mg ha−1 lime, 112 Mg ha−1 gypsum, and combinations of these amendments. The experimental plots were seeded with a mixture of bromegrass (Bromus inermis Leyss.), tall fescue (Festuca arundinacea L.), and alfalfa (Medicago sativa L.). Yearly analysis of coal refuse material (0–15 cm) showed that the concentrations of NH+4‐N, [NO−3 + NO−2]‐N, available P, and water‐soluble K were the highest in sludge‐amended treatments, but they decreased with time. Plant yields increased each year from 1978 to 1980 in treatments receiving lime, sewage sludge, or both amendments. The highest yield of 6.00 Mg ha−1 occurred in the 1980 sludge + lime treatment. In 1980, the order of dry matter plant yields by treatments was sewage sludge + lime > gypsum + sewage sludge + lime > lime > sewage sludge > gypsum + sewage sludge > gypsum + lime > gypsum = control. Coal refuse and tissue K levels indicated that supplemental K would be desirable for long‐term maintenance of a vegetative cover. The better survival of bromegrass and tall fescue, as compared to alfalfa, reflected the coal refuse pH and the shorter root system of the more acid‐tolerant grasses. Concentrations of Al, Fe, Pb, and Zn in composite plant samples from some treatments exceeded the phytotoxic limits for these metals in plants. Potential plant toxicity from metals in the coal refuse material was most likely reduced by reactions with the applied sewage sludge and lime.

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The effects of sewage sludge, lime, and gypsum on the chemical composition of coal refuse material were examined at a Fulton County, IL, land reclamation site. Treatments consisted of a control, 542 dry Mg ha−1 anaerobically digested sewage sludge, 89.6 Mg ha−1 lime, 112 Mg ha−1 gypsum, and combinations of these amendments. Analysis of coal refuse material (0–15 cm) from 1976 to 1981 showed that the sewage sludge + lime treatment was the most effective in maintaining the refuse pH, and in reducing water‐soluble Al and Fe, KCl extractable Al, and total acidity. Gypsum applications decreased the refuse pH and increased water‐soluble Al and Fe, KCl extractable Al, and total acidity. The effectiveness of treatments in reducing total acidity was sewage sludge + lime > gypsum + sewage sludge + lime > sewage sludge > lime > gypsum + sewage sludge > control > gypsum + lime > gypsum. Concentrations of water‐soluble Ca, Mg, and Na reflected the additions of these cations made by various treatments and the contribution of these cations to refuse electrical conductivity (EC). Profile sampling (0–100 cm) in 1976 and 1981 showed a decline in pH, and an increase in water‐soluble Al and Fe and total acidity in 1981 samples from the sewage sludge and gypsum treatments. The changes in the sludge treatment indicate there was a solubilization of metals from the refuse material and sewage sludge with time, as the surface pH (0–15 cm) declined, and a subsequent increase in the total acidity from metals and acidic by‐products leached to the 15‐ to 100‐cm depths of the coal refuse material. In the gypsum treatment, the changes observed in the 1981 profile samples reflected the leaching of H3O+, metals, and acidic by‐products of pyrite oxidation produced by exchange with Ca from the gypsum amendment.

In this report we describe the results of a study conducted to determine the rates of bacterial aerosol emission from the surfaces of the aeration tanks of the Metropolitan Water Reclamation District of Greater Chicago John E. Egan Water Reclamation Plant. This study was accomplished by conducting test runs in which Andersen six-stage viable samplers were used to collect bacterial aerosol samples inside a walled tower positioned above an aeration tank liquid surface at the John E. Egan Water Reclamation Plant. The samples were analyzed for standard plate counts (SPC), total coliforms (TC), fecal coliforms, and fecal streptococci. Two methods of calculation were used to estimate the bacterial emission rate. The first method was a conventional stack emission rate calculation method in which the measured air concentration of bacteria was multiplied by the air flow rate emanating from the aeration tanks. The second method was a more empirical method in which an attempt was made to measure all of the bacteria emanating from an isolated area (0.37 m2) of the aeration tank surface over time. The data from six test runs were used to determine bacterial emission rates by both calculation methods. As determined by the conventional calculation method, the average SPC emission rate was 1.61 SPC/m2/s (range, 0.66 to 2.65 SPC/m2/s). As determined by the empirical calculation method, the average SPC emission rate was 2.18 SPC/m2/s (range, 1.25 to 2.66 SPC/m2/s). For TC, the average emission rate was 0.20 TC/m2/s (range, 0.02 to 0.40 TC/m2/s) when the conventional calculation method was used and 0.27 TC/m2/s (range, 0.04 to 0.53 TC/m2/s) when the empirical calculation method was used.(ABSTRACT TRUNCATED AT 250 WORDS)