Impact on gas potential of primary sludge hydrolysis for internal carbon source production

• Abstract in UndeterminedTo operate biological nutrient removal processes efficiently, access to easily degradablecarbon is crucial. Internal production of good-quality carbon via hydrolysis of primary sludge has been proven to be a cost-effective way of securing the supply. This study confirms that a highqualitycarbon source can be produced by biological hydrolysis of preprecipitated primary sludge from Klagshamn wastewater treatment plant (WWTP). The possible yields of VFAs and soluble COD were determined and compared to a corresponding study performed one year earlier, also at Klagshamn WWTP. Considering the whole carbon and energy balance of a WWTP, the overallprofit of sludge hydrolysis has however been questioned, especially where sludge is utilised for anaerobic digestion and methane production. In this study it was shown in laboratory experiments that primary sludge hydrolysis and withdrawal of the solubilised carbon source did not result insignificantly lower methane production when the remaining sludge was digested compared to when the primary sludge was digested in its original condition. These results clearly contradict the common conception of that sludge hydrolysis for production of carbon source to facilitate nutrientremoval must lead to decreased gas production in the anaerobic digestion at WWTPs.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Nyckelord

Gas potential

hydrolysis

internal carbon source

methane

preprecipitated primary sludge

VFA

Publikations- och innehållstyp

kon (ämneskategori)

ref (ämneskategori)