76    ANAEROBIC COMPOSTING WITH METHANE RECOVERY
FROM AGRICULTURAL AND VILLAGE WASTES
M. A. Badawi, Research Fellow
F. C. Blanc, Professor
D. L. Wise, Professor
Northeastern University
Boston, Massachusetts
M. M. El-Shinnawi, Professor
S. A. Abo-Elnaga, Lecturer
University of Menofyia
Shibin El-Kom, Egypt
S. A. El-Shimi, Professor
Agricultural Research Center
Giza, Egypt
INTRODUCTION
In Egypt's rural communities, crop residues and animal manure are used for space heating and
cooking. This practice gradually depletes soil organic matter and contributes to air pollution. The
spreading of ash from the crop residue combustion on the soil adds more caustic material to the
existing highly alkaline topsoils. By combining the crop residues, animal manure and rural village
compostable solid waste and processing such materials in a controlled landfill type anaerobic reactor
with methane recovery, the equivalent fuel needs could be met and a soil enriching compost could be
produced.
This research was designed to examine such a bioconversion process and provide the process
performance parameters and endproduct information necessary for further engineering evaluations of
economic feasibility. An additional objective was the comparison of the compost production and
compost quality of the anaerobic composting process with aerobically produced compost generated
from the same raw waste ingredients. The experiments focused on three waste types: (a) agricultural
residues, (b) urban solid waste without agricultural residues and (c) a 1:1 mixture of (a) and (b) termed
a village waste.
BACKGROUND
Egyptian Solid Waste Practices
The results of a study by Environmental Quality International' show an estimated 11,000 ton per
day municipal solid waste generation rate in Egyptian cities. This waste is 60% organic matter on a
weight basis and suitable for processing into soil conditioner. Current solid waste disposal technology
in Egypt includes incineration, landfilling, and aerobic composting. Due to the higher moisture
content and capital cost, incineration has not proven to be a desirable technology. Landfilling in the
past has not been sanitary landfilling, however this is changing and the cost of the dumping alternative is increasing. There are a number of aerobic windrow composting demonstration plants in the 10
to 30 ton per day range operating in nine Egyptian cities to produce soil conditioner. Crop residues in
Egypt total about 22.6 million tons annually with 60% of this amount being used for fuel. Even
animal manure is used as a source of fuel for rural cooking and space heating. El Din et al.2 indicated
that one third of the energy consumption in Egypt was crop residue combustion. The combustion for
such residues takes place in low efficiency (5% to 10%) combustion devices which produce a large air
pollution load in residential areas.
46th Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
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