On the performance of a centralised digestion facility receiving seasonal agroindustrial wastewaters

Abstract

This work focuses on the anaerobic co-digestion as a method for treating seasonally generated, strong agroindustrial wastewaters. The co-treatment of such wastewaters secures the stable year-round operation of a treatment plant and is economically favorable (smaller capital costs) due to the use of a centrally located facility. Additionally, co-digestion has the benefit of the avoidance of nutrients (N, P) addition when a codigested wastewater contains nutrients in excess. Batch kinetic experiments codigesting piggery, olive-mill and dairy wastewaters have been carried out with piggery, olive-mill and dairy acclimated cultures. The microbial growth kinetics of each culture were calculated and used for comparison purposes. A unified mathematical model describing the co-digestion process has been developed and is capable of predicting the short-term response of a digester subjected to seasonal feed changes.