Preliminary observations on the copepods of Tudor Creek, Mombasa, Kenya

The zooplankton of Tudor Creek, a mangrove estuary in Kenya, was investigated from November 1984 to October 1985 at monthly intervals. One hundred and two copepod species were identified of which twelve were abundant. Densities are given for these species and their seasonal fluctuations are discussed

Methods for environmental monitoring of DOE waste disposal and storage sites. Semiannual progress report, November 1, 1985--March 31, 1986

This progress report contains an account of recent research efforts carried out at the Oak Ridge Research Institute, to raise antibodies in New Zealand White Rabbits which are specific for various strains of Thiobacillus ferrooxidans bacteria. It is then intended to use the antibodies, in a subsequent phase of the project, to develop one or more ELISAs, which would be used to analyze, both in the laboratory and in the field, the numbers and extent of dispersion of these microorganisms at acid mine drainage sites. This is important because it is the metabolic consequences of unrestricted dissemination of these bacteria which are responsible in large measure for the environmentally damaging acid run-off. Efforts to control the proliferation of these microorganisms have been relatively unfocused up to the present, because of the lack of suitably discriminating methods of assaying the effects of treatment. In this report, the authors describe the work carried out in the first section of the project, which has been concerned with the raising of the antibodies to the Thiobacillus ferrooxidans cultures. They given an account of how the various cultures were grown, how they were treated before being injected into rabbits, the injection protocol, how the animals were bled, and how the formation of IgG and its degree of specificity was assessed. Finally, they describe how large quantities of the various IgG fractions were prepared, and how and where they were stored

Methods for environmental monitoring of DOE waste disposal and storage sites: Proposal for optimizing a biological treatment system for denitrification of Y-12 waste streams. Semiannual progress report, November 1, 1987--March 31, 1988

The denitrification process at Y-12 involves the use of sludge to denitrify aqueous plating waste containing relatively high levels of NO{sub 3}. The process from time to time does not denitrify. The factors associated with the failure of the process remains to be resolved. The authors propose to resolve those factors by taking the following research approaches: (1) isolation and identification of microorganisms originating from sewage sludge which are associated with denitrification; (2) define physiological factors required for denitrification in this process system; and (3) define toxic factors associated with the aqueous waste that may affect the process of denitrification

Methods for environmental monitoring of DOE waste disposal and storage sites. Semiannual progress report, November 1, 1986--March 31, 1987

The Oak Ridge Research Institute has addressed the question of whether sulfate-reducing bacteria can be used in the remediation of heavy metal contamination. The authors have performed experiments in which mercury, lead, and cadmium have been removed from liquid media in which sulfate-reducing bacteria were growing. It is clear that heavy metals can be precipitated from solution by sulfate-reducers. The authors believe that the activity of these organisms can be enhanced to help stabilize mercury and other metals in waste holding pond sludges, sediments and in contaminated soils

Methods for environmental monitoring of DOE waste disposal and storage sites. Semiannual progress report, April 1--October 31, 1987

The authors have studied the precipitation of heavy metals by sulfide generated as a result of anaerobic sulfate respiration by sulfate-reducing bacteria. These bacteria are able to remove salts of mercury, lead, cadmium, nickel , and zinc from media that support sulfate respiration. A survey of metal-contaminated soils along East Fork Poplar Creek showed that all samples contained sulfate-reducing bacteria, but none had sufficient concentration of free sulfate to support active sulfate respiration. This situation represents a potential hazard in that sulfate-reducing bacteria can methylate mercury under conditions of low available sulfate, possibly releasing methyl mercury to the groundwater. The authors have proposed that amendment of soil with sulfate will promote sulfate respiration by bacteria. This would both enhance precipitation of heavy metals and also inhibit the formation of the toxic methylated metal compounds. Studies with soil columns demonstrated the feasibility of surface application of calcium sulfate to soil in providing sufficient concentration of sulfate at depths of at least 40 cm

Methods for environmental monitoring of DOE waste disposal and storage sites. Semiannual progress report, April 1--September 30, 1986

Sulfate-reducing bacteria were grown in media containing (1) mercury and (2) a mixture of heavy metals to determine if these bacteria could effectively precipitate heavy metals from an aqueous solutions. Previous studies have shown that (1) sulfate-reducing bacteria produce hydrogen sulfide and (2) that hydrogen sulfide reacts with various heavy metals producing insoluble complexes. Data from these studies showed that when bacteria were incubated with heavy metals for 2 to 4 days a marked decrease in the solubility of mercury, lead and cadmium resulted. For example, after incubation with sulfate-reducing bacteria 90% of the mercury, zinc, lead and cadmium, and 60% of the copper and iron were filterable. The results suggest that sulfate-reducing bacteria may be used to remove heavy metal contaminants from aqueous solutions