Effects of surface skewness on local shear stresses, biofilm activity, and microbial communities for wastewater treatment.

This study's objective was to assess attachment surface skewness (asymmetric surface height variation) effects on biofilm development. 3D printed molds were used to create surfaces with 300 μm features to provide opposite skewness but identical roughness values. Surfaces with negative skewness had consistently greater nitrite oxidation and biomass growth than other surfaces during biofilm development when studied in annular bioreactor systems.