ABSTRACT
The measurement of sludge bioavailability and biodegradability is important to assess the sludge potential as a source of carbon and energy during its biological stabilization. As the majority of biological sludge (secondary sludge) consists of biomass, an increase in sludge bioavailability can be achieved by using different techniques for cell lysis, which is aimed at releasing intracellular organics into the bulk solution and enhancing hydrolysis of particulate organic matter. This paper reviews the main methodologies currently used for cell lysis, which include thermal, ultrasonic and chemical techniques and a combination of these, as well as the analytical procedures that can be employed to assess the degree of lysis and sludge solubilization. In addition, this paper also discusses common techniques that can be used for measuring the biodegradability of sludge under aerobic and anaerobic conditions.
