HYDROLYSIS OF PARTICULATE ORGANICS IN ACTIVATED-SLUDGE SYSTEMS

Particulate matter constitute over 50% of the organic load in domestic wastewater. In activated sludge systems a portion of these particulat es are hydrolysed and degraded. Experimental methods were developed an d used for estimating the rate of hydrolysis of these particulates. Th ese included ways to distinguish between biological and non-biological VSS in an activated sludge mixture. From batch experiments an average specific hydrolysis rate coefficient of 4.61 10(-4)l(mg day)(-1) was obtained for raw primary suspended solids and 6.63 10(-4)l(mg day)(-1) for non-settleable suspended solids. The specific hydrolysis rate coe fficients for raw wastewater in continuous flow experiments was determ ined as 3.07 10(-3)l(mg day)(-1), which is substantially higher than i n batch tests.