Document Type
Thesis
Date of Award
1981
Abstract
The indiscriminate discharge of industrial wastewaters such as those containing high levels of ammonia, has resulted in toxicity to animal and human life and in eutrophication of receiving streams. Stringent government regulations now limit effluent volumes of affected industries. The destructive distillation of coal to produce coke, which is used as a reducing agent for iron and steel production, may result in ammonia levels above 300 mg/L in the wastewater. iron and steel industry has therefore been required to seek an effective and economical method of removing the ammonia from its effluent. The limitations, including high costs of various physiochemical methods of ammonia removal have made nitrification, the biological oxidation of ammonia, an attractive alternative. TheNitrification in an activated-sludge process is, however, sometimes inconsistent. Thus, in order to maximize the efficiency of this biological process, it is essential to improve our understanding of the population dynamics and physiology of the nitrifiers by developing a fast and accurate method for enumerating the nitrifiers. This will enable correlations to be made between the population densities and oxidation rates of the ammonia oxidizers.A fluorescent antibody (FAb) technique was developed for the purpose of providing reliable estimates of the number of nitrifiers in coke-plant mixed liquor. The specificity of the labelled antibody and the accuracy of the technique were assessed with adequate controls.Results obtained from the FAb technique indicate that coke-plant mixed liquor contains about four orders of magnitude more Nitrosomonas cells than found by most probable number estimates. Nitrosomonas was found to comprise about 2 percent of the total cells in coke-plant mixed liquor maintained at a 25-day solids retention time (SRT) or greater, and about 1 percent at 4.2 days SRT.Correlations between levels of effluent ammonia and the population dynamics of Nitrosomonas indicate that the rate of ammonia removal in coke-plant mixed liquor is affected by both the number of nitrifiers and the activity per cell. The ammonia-oxidizing capacity per cell was found to be influenced significantly by the concentration of substrate (i.e., ammonia) in which the organisms are growing. A model is presented which suggests that the rate of ammonia-oxidation per cell is dependent upon the surface area of the peripheral intracellular membranes characteristic of Nitrosomonas. Nitrosomonas from the coke-plant mixed liquor and a pure culture of Nitrosomonas europaea increased the intracellular membrane surface area by increasing the number of intracellular membranes. Increases in the number of membranes and increasing oxidative capacity per cell correlated with increasing levels of available substrate.
Recommended Citation
Martin, Randy Harlis, "Variations in the Oxidative Rates of Nitrosomonas europaea in Coke-Plant Activated Sludge." (1981). All ETDs from UAB. 7128.
https://digitalcommons.library.uab.edu/etd-collection/7128
Comments
MS - Master of Science/Master of Surgery; ProQuest publication number 31752048