Since crude glycerol and PM-GLY mixtures have different physical
and chemical properties from a water matrix sample (density,
viscosity, boiling point, etc.), a series of modifications in the standard
methods for the examination of water and wastewater procedures
(APHA, 2005) were undertaken. Mixtures were established
on a weight basis since it was difficult to pour the desired measured
volume of GLY out of the receptacle due to its viscosity. Total
solids were measured after an overnight desiccation of the sample
to 105 C (liquid could still be found in the crucible as GLY’s boiling
point is about 290 C). Volatile solids were determined through the
following muffle temperature program: room temperature ramp to
250 C at 15 C min1
, hold 60 min; ramp to 400 C at 15 C min1
,
hold 30 min; ramp to 550 C at 15 C min1
, hold 90 min. Cleaning
64 S. Ast