Reduction of Sewage Sludge Production by using Mechanical Disintegration

Georg W. Strünkmann1) and Johannes A. Müller1),2)

1) Inst. of Mechanical Process Engineering, 2) Inst. of Sanitary Engineering
TU Braunschweig, P.B. 3329, 38029 Braunschweig, Germany


The possibility to reduce excess sludge production by integrating mechanical disintegration of sludge into the waste activated sludge process is investigated as part of an international research project. Mechanical disintegration techniques can be used either to disintegrate sludge flocs or also to break up cell walls of micro-organisms depending on the energy input and the kind of forces. With both floc rupture and cell destruction growth and degradation of sludge could be influenced. The mechanical stress is produced using different kinds of energy like shear- or pressure forces. This can be done using a number of machines, which are compared in the project like stirred ball mill, high pressure homogenizer, ultrasonic homogenizer, jet-smash technique and shear-gap homogenizer. Depending on the machine and operational parameters various types of stress can be imposed on the sludge and the stress intensity can be regulated from floc destruction to cell disruption. The influence of the mechanical stress on the growth rate of the sludge can be tested in batch sequenced respirometers. The effect of stressing the sludge on excess sludge production, on the pollution removal capacity of the waste activated sludge process and on the sludge characteristics can be investigated in lab-scale wastewater treatment set-ups.

Key Words

Excess Sludge, Sludge Growth, Mechanical Disintegration, Floc Rupture, Dewatering


G. Strünkmann und J. Müller (2002). Reduction of Sewage Sludge Production by using Mechanical Desintegration. World Congress of the International Water Association, Melbourne, Australia, April 2002, Conference Proceedings CD-ROM