Biofilter scaling procedures for organics removal: A potential alternative to piloting

• Published in: Water research (Oxford) Vol. 151; pp. 87 - 97
• Main Authors: McKie, Michael J., Ziv-El, Michal C., Taylor-Edmonds, Liz, Andrews, Robert C., Kirisits, Mary Jo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.03.2019
• Subjects: Bench-scale biofilters; Biofilter scaling procedure; Biomass characterization; Enzyme activity; Microbial community analysis; Organics removal; Biofilter scaling procedure; Microbial community analysis; Enzyme activity; Biomass characterization; Bench-scale biofilters; Organics removal
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2018.12.006

To provide information for the design and improvement of full-scale biofilters, pilot-scale biofiltration studies are the current industry standard because they utilize the same filter media size and loading rate as the full-scale biofilters. In the current study, bench-scale biofilters were designed according to a biofilter scaling model from the literature, and the ability of the bench-scale biofilters to accurately represent the organics removal of pilot-scale biofilters was tested. To ensure similarity in effluent water quality between bench- and pilot- or full-scale biofilters at the same influent substrate concentration, the tested model requires that either mass transport resistance or biofilm shear loss takes primacy over the other. The potential primacy of mass transport resistance or biofilm shear loss was evaluated via water quality testing (dissolved organic carbon, specific ultraviolet absorbance, liquid chromatography – organic carbon detection, trihalomethane formation potential, and haloacetic acid formation potential). The biofilters also were characterized for adenosine triphosphate (ATP) content, enzyme activity, extracellular polymeric substances, and microbial community structure. The results of this study indicate that biofilm shear loss takes primacy over mass transport resistance for bench-scale biofilter design in this system; thus, bench-scale biofilters designed in this manner accurately represent organics removal in pilot-scale biofilters. Applying this scaling procedure can reduce filter media requirements from many kilograms to just a few grams and daily water requirements from thousands of liters to less than 10 L. This scaling procedure will allow future researchers to test alternative treatment designs and operating conditions without the need for expensive pilot-scale studies. [Display omitted] •Biofilter scaling model was applied for organics reduction for the first time.•Biomass character and water quality were utilized to evaluate model assumptions.•Biofilm shear loss has primacy in scaling procedure for biofilters removing organics.•Appropriately scaled biofilters can greatly reduce water and media requirements.