Comparison between disintegrated and fermented sewage sludge for production of a carbon source suitable for biological nutrient removal.
There is a need to investigate processes that enable sludge re-use while enhancing sewage treatment efficiency. Mechanically disintegrated thickened surplus activated sludge (SAS) and fermented primary sludge were compared for their capacity to produce a carbon source suitable for BNR by completing nutrient removal predictive tests. Mechanically disintegration of SAS using a deflaker enhanced volatile fatty acids (VFAs) content from 92 to 374 mg l(-1) (4.1-fold increase). In comparison, primary sludge fermentation increased the VFAs content from 3.5 g l(-1) to a final concentration of 8.7 g l(-1) (2.5-fold increase). The carbon source obtained from disintegration and fermentation treatments improved phosphate (PO(4)-P) release and denitrification by up to 0.04 mg NO(3)-Ng(-1)VSS min(-1) and 0.031 mg PO(4)-Pg(-1)VSS min(-1), respectively, in comparison to acetate (0.023 mg NO(3)-Ng(-1)VSS min(-1)and 0.010 mg PO(4)-Pg(-1)VSS min(-1)). Overall, both types of sludge were suitable for BNR but disintegrated SAS displayed lower carbon to nutrient ratios of 8 for SCOD:PO(4)-P and 9 for SCOD:NO(3)-N. On the other hand, SAS increased the concentration of PO(4)-P in the settled sewage by a further 0.97 g PO(4)-P kg(-1)SCOD indicating its potential negative impact towards nutrient recycling in the BNR process.
Soares
Ana
A
Centre for Water Science, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK. a.soares@cranfield.ac.uk
Kampas
Pantelis
P
Maillard
Sarah
S
Wood
Elizabeth
E
Brigg
Jon
J
Tillotson
Martin
M
Parsons
Simon A
SA
Cartmell
Elise
E
D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry; D005285:Fermentation; D009584:Nitrogen / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods; D014873:Water Pollutants / Q000737:chemistry; D018508:Water Purification / Q000379:methods
D005227:Fatty Acids; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D014873:Water Pollutants; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen