Bioaugmentation treatment of a novel microbial consortium for degradation of organic pollutants in tannery wastewater under a full-scale oxic process

Tannery wastewater contains a variety of complex organic compounds that is usually refractory for biodegradation. In this study, the research objective was to couple novel beneficial microorganisms to oxic processes to degrade organic pollutants at an industrial-scale tannery wastewater treatment plant. The characteristics of the conversion and biodegradation of organic material are also discussed. Although several negatively influencing factors (e.g., chromium) for the removal of organic material were present in this treatment system, an average chemical oxygen demand (COD) removal efficiency of 95.2% was achieved during the 328-day operation. Moreover, the results of a Fourier transform infrared spectroscopy and three-dimensional excitation and emission matrix fluorescence spectra were consistent, showing that organic pollutants (e.g., protein-like, polysaccharide-like, and humic acid-like materials) showed great conversion and synchronous degradation under biotreatment. Humic acid-like and protein-like organic matter were the main components of the influent and effluent organic material, respectively. This was attributed to inoculation of a special composition of beneficial microorganisms with abundant functional genes related to the degradation of organic material.