J. A. Müller
Institute of Sanitary Engineering and
Institute of Mechanical Process Engineering,
Technical University of Braunschweig, Post Box 3329, D-38023 Braunschweig,
Germany
E-mail: jo.mueller@tu-bs.de, http://www.tu-bs.de/~jom
Abstract:
This paper focuses on
mechanical disintegration and will compare its results to thermal and ozone
treatment. Several mechanical methods can be used for disintegration of sewage
sludge. The methods differ in energy consumption and suitability of the
machines for practical application, which is of great influence on the
selection of the method. Thermal disintegration processes have a higher energy
consumption than mechanical methods, but they can use low cost thermal energy
instead of electrical energy. The highest solution of organic components is
achieved using ozone treatment. Several reuse options of disintegrated sludge
in aerobic and anaerobic processes are explained. An acceleration and enhancement
of the anaerobic stabilisation process is observed, especially if excess sludge
is used. Mechanical disintegration leads to better results than thermal
treatment in the range of 60 to 130 °C. For the aerobic process the
substitution of external proton donors is of special interest. High
denitrification rates can be achieved, if the sludge is adapted to the
substrate. Increasing the concentration of nitrogen and phosphorous in the
supernatant, in order to recycle these valuable compounds, mechanical disintegration
and ozone treatment seem to be more suitable than thermal disintegration.
Keywords:
biodegradability, mechanical disintegration, ozone treatment,
pre-treatment, thermal disintegration
Origin:
J. Müller (2000). Pretreatment Processes for the recycling and reuse of
sewage sludge, Water Science and Technology, IWA Publishing 2000, Vol 42 No
9, pp. 167-174 and in IAWQ Conference on Disposal and Utilization of Sewage
Sludge, October 1999, Athens, Greece, pp. 282-289