Scale-Up Methodology for Biological Filtration Removal of Dissolved Organic Matter

Abstract

Abstract

A scale-up methodology was developed and verified that utilizes bench-scale biofilter results to simulate field-scale (pilot or full scale), flow-through biofilter performance. This methodology builds on recirculating batch reactor methods combined with single-pass flow-through methods at empty bed contact times (EBCTs) equivalent to the field scale. This method allows for control of variables that are often not controllable at the field-scale level, that is, influent primary and secondary substrate concentrations, temperature, and replication. The robustness of the method was verified using dissolved organic carbon (DOC) removal in one drinking water (DW) and two wastewater (WW) effluents and the removal of 12 trace organic contaminants in one WW effluent. The average absolute difference (delta) between bench- and pilot-scale results for 14 comparisons was 2% for DOC removal. Experimental DOC results were not impacted by the range of biofilter hydraulic loading rates (HLRs) with a WW effluent and a DW effluent, confirming that at Damköhler number II values less than 0.1, the biofilters were reaction rate limited with little contribution from mass transfer. This allows for the use of lower HLRs and shorter filter media depths at the bench scale to yield equivalent EBCTs of field scale. Utilizing bioacclimated media, this bench-scale methodology could expedite biofilter implementation in DW and water reuse treatment plants.