Denitrifying Bioreactor <i>In Situ</i> Woodchip Bulk Density

Highlights The bulk density of woodchips in denitrifying bioreactors the field is unknown. In situ estimation methods were developed for use during construction or excavation. Dry densities aged at bioreactor bottoms lower than previous literature values. Moisture and particle size explained some, but not all, variation densities. Abstract . Woodchip a governs system hydraulics, this prime physical attribute has never been estimated situ. objectives twofold: (1) to establish estimates woodchip field, (2) evaluate causal factors resulting impacts these estimates. Proof-of-concept pilot-scale using three ways estimate volume: surveying excavated area, pumping excavation full through flow meter, iPhone Light Detection Ranging (LiDAR). These then further tested two new old full-size bioreactors. Additional ex (off-site) testing with associated included analysis along moisture gradient size, density, wood composition, hydraulic property testing. dry based on entire volume (206-224 kg/m3) similar values from lab-scale studies. bottom (22-mo. 6-y) unexpectedly low (120-166 kg/m3), given that would presumably be most compacted. moisture-content corrected influenced by high contents (&amp;gt;70% wet basis). somewhat mixed across dataset, general, smaller had higher larger, several sourced Although zone shown relatively low, permeability coefficients under those packing conditions did differ original woodchips. LiDAR-based method was practical large-scale, evaluations allowed precision small features (e.g., vertical reactor edges, drainage fittings). Keywords: Compaction, Cone penetrometer, Drainable porosity, LiDAR, content, Survey.