Selected Chemoautotrophic Processes in Wastewater Treatment: Low Temperature Nitrification Inhibition by an Azo Dye and Biofiltration for Odor Control of Hydrogen Sulfide

Biochemical processes by chemoautotrophs such as nitrifiers and sulfide and iron oxidizers are used extensively in wastewater treatment. The research described in this dissertation involved the study of two selected biological processes utilized in wastewater treatment mediated by chemoautotrophic bacteria: nitrification (biological removal of ammonia and nitrogen) and hydrogen sulfide (H2S) removal from odorous air using biofiltration. A municipal wastewater treatment plant (WWTP) receiving industrial dyeing discharge containing the azo dye, acid black 1 (AB1) failed to meet discharge limits, especially during the winter. Dyeing discharge mixed with domestic sewage was fed to sequencing batch reactors at 22C and 7C. Complete nitrification failure occurred at 7C with more rapid nitrification failure as the dye concentration increased; slight nitrification inhibition occurred at 22C. Dye-bearing wastewater reduced chemical oxygen demand (COD) removal at 7C and 22C, increased