Biological nitrogen removal from wastewater typically happens through aerobic nitrification (from ammonia to nitrate) and anoxic denitrification (nitrate to nitrogen gas). This is usually carried out in two separate process tanks other than in a sequencing batch reactors (SBRs). However, it is more energetically efficient to convert ammonia directly to nitrogen gas, since it requires less oxygen.
Features - Process biology
The non-Newtonian nature of sewage sludge means that its measured viscosity µs varies with shear rate due to the shear-dependent deformation of the flocculant solids (Yang et al, 2009). Viscosity affects the shear at the membrane interface, shear being a key parameter in promoting flux, and the dependency of apparent viscosity on temperature may then also be significant in determining flux.