Respirometric evaluation of biodegradation kinetics for ultrasonic disintegrated domestic sludge

Abstract

AbstractThis paper studied the suitability of an internal carbon source for nitrogen removal enhancement with mechanically disintegrated waste activated sludge (WAS) using ultrasonication. In this context, particle size distribution (PSD)-based chemical oxygen demand (COD) fractionation was performed, and denitrification rates of the total, particulate and soluble range of the disintegrated WAS sample were determined. The effect of ultrasonic disintegration on biodegradation characteristics of the domestic WAS was evaluated by respirometry. The ultrasound density of 1 W/mL was applied to the raw WAS, and the specific energy was calculated as 52.8 kJ/g TSS. Two thousand and eight hundred milligram per liter of COD, which corresponded to the 24% of the total COD, was released from the WAS. The PSD-based COD fractionation showed that the COD concentration at the particulate range (65.4%) was significantly high followed by the soluble range (15.5%), and 54% of the solubilized COD was accumulated at the <2 nm ...