16 Organic Waste Recycling: Technology and Management
uses in the treatment operation. Treated effluent form the maturation ponds is used
to irrigate padlocks, previously used for land and grass filtration. These padlocks
are used for cattle and sheep grazing.
1.3.4 Decentralized sanitation in western Africa
A research project on the use of composted organic wastes from urban households
for phytosanitary purposes in the peri-urban agriculture in Western Africa was
reported by Streiffeler (2001). In Senegal, the organic materials, separated from
household’s solid wastes, were composted for 2-3 months before uses in
agriculture. Temperature rises in the compost heap were up to 70ºC, sufficient to
kill any pathogenic organisms present in the waste materials. The compost extracts
were applied to plants that were most susceptible to diseases, such as tomato and
cassava, and the preliminary results obtained showed some reduced rates of plants
succumbing to diseases. The project outcomes suggested the benefits of using
organic compost as fertilizers and for controlling of plants diseases.
1.3.5 Cogeneration at Rayong Municipality, Thailand
(http://www.cogen3.net)
The Rayong municipality has a population of about 60,000 in the year 2006 and is
located 180 km east of Bangkok city. With financial support from the central
government, it has built a solid waste treatment facility for waste stabilization,
electricity generation and production of soil conditioner. As shown in Figure 1.8,
the facility costing US$ 4.3 million includes an anaerobic digestion tank, a biogas
storage dome and a biogas fired co-generator. It is designed to handle at full
capacity 25,550 tons of municipal solid wastes annually (or 70 tons per day), with
the projected biogas production of 2.2 million cubic meters per year, electricity
generation of 5,100 MWh and production from the digested solids wastes of 5,600
tons per year of soil conditioners containing 35 % moisture content. Financial gains
from the sales of mainly electricity and soil conditioners are expected to pay the
invested cost in 10 years.