A separate reactor for batch accumulation was applied for the production of PHA. The batch reactor was fed with OFMSW FL in Period I and with PS & OFMSW FL in Period II.
The biomass (2 L) was collected at the end of the famine phase of the SBR cycle and was used as new inoculum for a fed-on-demand batch reactor to examine the PHA accumulation capacity of the biomass.
The biomass was concentrated gravimetrically applying 30 min of settling and removing the supernatant in order to reduce the nutrient level from the selection SBR. In the accumulation reactor (1 L reactor volume having 800 mL of working volume) the biomass was placed under continuous agitation and aeration was provided so that the DO level was always above 2 mg L1.
The accumulation reactor was connected with a suitable respirometric device (MARTINA, SPESS
Italy) which automatically recorded online DO, OUR, pH and temperature using suitable DO (type WTW, CellOx 325), pH (Polyplast Pro) and temperature (PT100) probes.