Thesis Details


Thesis Title: AN EVALUATION OF ANOXIC/AEROBIC TREATMENT FOR THE REMOVAL OF CHEMICAL OXYGEN DEMAND AND FIBER REACTIVE AZO DYE COLOR
Thesis Author: Jamie Pisczek
Abstract: Introduction Environmental regulations exist to ensure the quality of the environment and these regulations include the characteristics of the water discharged by manufacturing locations. Industry is constantly searching for more effective and economical methods for meeting these regulations. Textile dye effluent is mainly characterized by salts, organic matter, and color. The standard method of treating textile wastes is the activated sludge process, in which aerobic microorganisms are used to decompose organic waste. This process is effective and cost efficient for the reduction of organic matter and toxicity. A biological, chemical, or physical process can be used to remove the color in the wastewater with varying effectiveness depending on the types of dyes present. However, there is no effective and universal method for the removal of color resulting from the presence of all dye types. Chemical and physical decolorization processes are often expensive and, therefore, biological processes are preferred (5). Many reactive dyes are of the azo chemical class and contain nitrogen  nitrogen double bonds which can be broken to achieve decolorization. Aerobic processes utilize oxygen, which can inhibit azo bond cleavage. Anoxic and anaerobic processes are capable of azo bond cleavage because they require an environment with a low level of dissolved oxygen (35). As a result, anoxic and anaerobic processes are capable of more efficient decolorization than the conventional aerobic system. Despite the drawbacks of the conventional aerobic system in regard to color removal, aerobic processes are very effective for the removal of chemical oxygen demand and toxicity. While anaerobic processes require special equipment, aerobic treatment lagoons can be easily modified to incorporate an anoxic pre-treatment (3). This research investigated the applicability of a sequential anoxic/aerobic treatment process for the removal of chemical oxygen demand and fiber reactive azo dye color from wastewater. This type of treatment process has the potential to be more effective and less expensive than a conventional aerobic system with tertiary chemical or other advanced post-treatment for color removal. The specific objectives for this study were to: 1. Develop a viable biomass that could be effective in both an anoxic and aerobic environment. 2. Compare the degradation of COD by this biomass under anoxic vs. aerobic conditions. 3. Determine the kinetic parameters for COD removal for each phase of the anoxic/aerobic process and an aerobic control process, using fully acclimated biomass. 4. Compare the degradation of fiber reactive azo dyes by this biomass under anoxic vs. aerobic conditions. 5. Determine the kinetic parameters for color removal (as measured by dye concentration and ADMI color value) for each phase of the anoxic/aerobic. 6. Compare the color removal for the dyes studied in terms of dye structure. 7. Make recommendations for the design of an anoxic/aerobic sequential wastewater treatment facility.