Dual hydrolysis model of the slowly biodegradable substrate in activated sludge systems

Experimental assessment of the hydrolysis rate coefficients for both domest ic sewage and a number of industrial wastewaters was performed with emphasi s on two different hydrolysis mechanisms associated with the readily and sl owly hydrolyzable COD fractions. The adopted dual hydrolysis model was just ified on the basis of significantly different rate constants. The hydrolysi s rate of particulate COD occurred at such a slow rate that would significa ntly interfere with endogenous decay.