A QUANTITATIVE APPROACH TO PREDICT ... - SuSanA

wastes. 154 These two ‘raw materials’ are then processed into soil conditioners and
fertilizers. A detail of how the fertilizer is prepared is explained in section 3.2.
3.2. The preparation of the ecosan fertilizer
One of the recommended ways in managing wastes is through composting. 155 Quoting
from Gomez, “Composting is a microbial reaction of mineralisation and partial
humification of organic substances which, under optimum conditions, take place within
a month.” 156 It mostly required that the composting process should be aerobic so that the
organic materials can be mineralised and humified. When Aerobic co-composting
process is used no odour is produced and the high temperature is effective in reducing
the pathogens of the wastes. 157 There are some conditions that should be met in waste
disposal industries to make compost suitable. These are; there should be a brief process
with low energy consumption, the end product should be of standard for agriculture
purposes as well as having satisfactory fertilizer value and the end product and the plant
used in production should be hygienic. 158 There are two main ways of making
composting which can either be open system or closed system where they all have their
own advantage and disadvantages and the compost can be made from wastes from food,
tree barks, saw dust, sewage sludge, household wastes and others. The quality of the
compost depends on the mixture of the wastes used. 159
Considering the preparation of the ecosan fertilizer which at one point in this section
may be called co-compost (because it comprises of two raw materials ) and at another
time called comblizers (based on the addition of other component), the two set of wastes
needed are firstly gathered. The municipal solid wastes from the households, markets
and other public places are brought to the project site from the metropolis, they are
sorted out into different fractions like stones, plastics, nylons, papers, metals, textiles,
wood, and organic solid wastes. The organic wastes are then separated for use. The
human excreta are got from the septic tanks and the public toilet sludge from the pit
latrines. These set of wastes are used because they complement each other. 160 The
faecal sludge is relatively high in nitrogen and moisture whiles the solid waste is high in
154 Olofunke, Cofie and Kone, Doulaye, 2008, pp. 1-2.
155 Dijkema, Reuter and Verhoef, 2000, p. 635
156 Gomez, 1998, p. 310
157 Rabbani, et al 1983: p.10.
158 Ibid
159 Gomez, 1998, pp. 311-.313
160 Olofunke, Cofie and Kone, Doulaye, 2008, pp. 1-2
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