A PILOT-SCALE STUDY OF THE EFFECT OF BIOLOGICAL ADDITIVES ON BIOSOLIDS PRODUCTION

In this study, the potential of two biological additives to increase bio-solids removal in a wastewater treatment plant was tested using pilot-scale tanks. The tests were run in cooperation with the Hilliard Fletcher wastewater treatment plant (WWTP) in Tuscaloosa, AL. A pilot plant consisting of two activated sludge model tanks was set up to run in-line with the Tuscaloosa WWTP. Effluent from the overflow weir of the primary clarifier served as the influent to the pilot-scale tanks. After achieving steadystate, the biological additives, which included a bio-stimulant and a bio-enhancement product, were added to the pilot tanks. Two of the pilot tanks were used to assess the effects of the biological additives and one tank served as a control. This additive loading occurred over a period of 7 weeks; during which time TSS removal and COD removal were tested. This study found that the biological additives do improve bio-solids removalwith some statistical certainty. One product reduced bio-solids production at the 90 % confidence level and the other reduced bio-solids production at the 75 % confidence level. Use of the additives in full-scale plant operations may not be economically feasible for some wastewater treatment plants.