للكاتبين S. Bayoumi1 , K. Ewida1, and D. Saad El-Din1
1Environmental Engineering Department, Faculty of Engineering, Zagazig University, Egypt.
One of the main challenges facing wastewater treatment reactors remains the enhancement of its
design and/or operation. In recent years, numerous designs and/or configurations of these reactors
have been developed to optimize the anaerobic treatment of wastewater. The ability of clay
minerals to create a favorable environment for the growth of microorganisms as well as to work
as a catalyst of the reactions and degradation of organic compounds has been addressed for long
The present study investigated the influence of mixing the seeding sludge with clay minerals on
the efficiency of raw sewage treatment in a pilot-scale model simulating UASB reactor. Kaolinite
and montmorillonite are utilized in the present work as clay minerals, while organics (BOD and
COD) and solids (SS and DS) are selected as assessment parameters of the treatment process.
While the two UASB models constructed and operated within the work-frame of the present work
are identical and operated under the same operation conditions and scenario, one of them was
seeded with a mixture of sludge and kaolinite and the other was seeded with a mixture of sludge
and montmorillonite. Different mixing ratios (weight-basis) of clay minerals and sludge (Wc:Ws)
ranged from 0% to 80% have been investigated in the present study.
Among the results obtained from the experimental program executed within the scope of the
present work is that montmorillonite enhances the UASB efficiency regarding the removal of
organics and solids from raw domestic wastewater better than kaolinite. The enhancement
reached 20%, 30%, and 25% in the % removal of BOD, COD, and SS respectively upon mixing
the sludge seeded to the UASB with montmorillonite at a mixing ratio (Wc:Ws – weight-basis) of
40%. While mixing ratios higher than 40% doesn’t rise the gained enhancement that much
amount, the mixing ratios lower than 40% yield a considerable enhancement.