Medicine and Health Sciences Commons^™

The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser

KWRRI Research Reports

Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC₅₀ ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to > 68 mg/L for chloroform, 3.01 to 5.56 mg/L …

Effects Of Organic Compounds On Amphibian Reproduction, Wesley J. Birge, Jeffrey A. Black, Robert A. Kuehne

KWRRI Research Reports

Aquatic toxicity tests were conducted with atrazine, carbon tetrachloride, chloroform, methylene chloride, trisodium nitrilotriacetic acid (NTA), and phenol. Each compound was administered to developmental stages of three to five amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. Test responses included lethality and teratogenesis. Different amphibian species exhibited varying degrees of tolerance to the selected compounds. Greatest tolerance usually was observed for the more broadly adapted semi-aquatic and terrestrial species (e.g., Bufo americanus, Bufo fowleri). The more sensitive amphibians usually included those species which normally are restricted to aquatic or moist habitats (e.g., Rana …

A Study Of Naturally Occurring Algicides Produced By Freshwater Algae, Denny O. Harris, Harry D. Caldwell

KWRRI Research Reports

The mode of action of the algicide produced by Pandorina morum was examined by exposing Volvox globator and isolates spinach chloroplasts to a partially purified algicide preparation. Oxygen evolution of Volvox, whole chloroplasts and broken chloroplasts (minus the Calvin cycle),was reduced indicating that the algicide inhibits the light reactions of photosynthesis. Oxygen evolution studies of other Volvocaceae confirmed the observation that Pandorina morum is not significantly influenced by its own inhibitor. Molecular weight approximation by gel filtration established that the inhibitor has a low molecular weight (probably below 100 mw). Field studies indicate that this algicide has tremendous potential as …

Metabolic Capabilities Of Sulfur Oxidizing Bacteria And Their Role In Water Pollution, M. I. H. Aleem

KWRRI Research Reports

This report describes investigations into the physiology of microorganisms that are commonly involved in the oxidation of inorganic sulfur compounds. The metabolic activities of these bacteria play a potent role in several fields of economic importance such as strip mining operations, water pollution, corrosion, metallurgy, petroleum technology and soil fertility processes.

The oxidation of inorganic sulfur compounds was studied in the chemolithotrophs Thiobacillus denitrificans, Thiobacillus A₂, Thiobacillus neapolitanus, and a photolithotroph Rhodopseudomonas palustris. Cell suspensions from all of the thiobacilli catalyzed completely the oxidation of sulfide, thiosulfate, and sulfite to sulfate. The oxidation of thiosulfate in R. palustris …

A Study Of Water-Soluble Inhibitory Compounds (Algicides) Produced By Fresh-Water Algae, Denny O. Harris, Manhar C. Parekh

KWRRI Research Reports

A complex system of growth inhibitors was observed in the green algae (Volvocaceae). Inhibitors were found in the culture filtrates of some genera which limit their own growth (autoinhibitors) while others in the family produce substances which check the growth of other genera (heteroinhibitors). These inhibitors were destroyed by autoclaving. It was decided that Pandorina morum, which produced the strongest inhibitor and Volvox tertius, the most sensitive to the inhibitor would make an excellent model system for a study of the chemical and physical properties of these naturally occurring algicides. The algicide could be removed from actively growing cultures about …

Factors Regulating The Growth Of Algae In Continuous Culture In Diluted Secondary Sewage Treatment Plant Effluent And Subsequent Biodegradability, Edward G. Foree, Caroline P. Wade

KWRRI Research Reports

Heterogeneous algal cultures were grown in laboratory continuous culture in continuous flow, completely mixed chemostats in secondary sewage treatment plant effluent diluted to give an ammonia nitrogen concentration of 10 mg/1. Variables were lighting, pH, carbon dioxide availability, and hydraulic residence time.

Optimum growth occurred under pH 7.0, excess CO₂, and continuous lighting conditions. The availability of artificially supplied excess CO₂ greatly increased the mass (standing crop) at steady-state over that produced under otherwise identical conditions for all residence times studied. For the case of excess CO₂ availability, the nitrogen concentration in the algal cells regulated …

Algal Growth And Decomposition: Effects On Water Quality, Edward G. Foree, John S. Tapp Jr.

KWRRI Research Reports

The chemical composition of algae grown in batch culture depends mainly on environmental conditions, nutrient availability, presence of predators, cell age, and species. The effects of nutrient availability and cell age on the composition of three unialgal cultures (algae + bacteria) and one hetergeneous culture (algae + bacteria + microscopic animals) were evaluated. The cultures were grown in batch culture under both nutrient-abundant and nutrient deficient conditions and the changes in compositions were observed. Luxurious uptake where nutrients are incorporated into cellular protoplasm at levels greater than those necessary for growth, and super-luxurious uptake, where some nutrients are stored rather …