The potential for sorption of soluble organic matter on anaerobic biomass is currently under investigation by the author and coworkers at Iowa State University. Biosorption is defined as the uptake or accumulation of particulates and chemicals by microbial biomass. The anaerobic biosorption process utilizes the sorption capabilities of active biomass for the treatment of wastewater. Biosorption is a rapid process. About 40% removal of organic matter was obtained in only 15 minutes after the substrate was brought in contact with the biomass;This dissertation presents the results of preliminary investigations on the effects of various factors on the biosorption process. The primary objective of this research was to determine the applicability of anaerobic biomass as a potential sorbent for organic matter and to quantify the results in terms of isotherms. The effects of mixing times, temperature, substrate concentration, biomass concentration, and granular biomass particle size were also studied;Anaerobic biomass was grown at 35°C in 10-liter source reactors, operated as anaerobic sequencing batch reactors (ASBR). Biosorption experiments were performed with active biomass in two liter batch reactors on a synthetic milk waste. The particle size distributions of the granular biomass were determined using an Automatic Image Analysis system. Temperature studies were significant. Better removals were obtained at higher temperature than at lower temperature. It was observed that wastes at temperatures as low as 7°C could be treated without the application of external heat;Higher removals were obtained with the small granular biomass than with the large granules. Increasing the biomass concentration resulted in a significant increase in the percentage removal of organic matter. Another method of improving biosorption was to operate a number of sorption reactors in series. High overall COD removals were obtained in a series of three reactors. The results were expressed in terms of adsorption isotherms. The data conformed well to both the Freundlich and the Langmuir adsorption models.