MOROCOMP (LIFE TCY05/MA000141) - Unit of Environmental ...

Table 4: Micro-biological parameters of primary sludge used in the 1 st composting trial
Micro-biological parameters
Primary sludge
Total coliforms Log10 MPN/10g DS 9.53
Faecal coliforms Log10 MPN/10g DS 8.83
Helminth eggs /10g DS 23.00
5.1.2. Composition of the composting raw material
The feedstock material of the 1 st composting trial comprised of primary sludge from
El Jadida city and sugar beet leaves. The quantities of each material used are given in
Table 5.
Table 5: Composition of the mix used for composting in the 1 st composting trial
Raw material
Kg w.w.
Primary sludge 700
Sugar beet leaves 650
As has been stated previously primary sludge acquired high moisture content due to
the fact that there was not dewatering installations in the region where primary sludge
was produced. Therefore composting primary sludge individually was not considered
appropriate and the addition of a bulking agent such as sugar beet leaves would
modify the physical (moisture content, structural support, porosity, aeration) as well
as the chemical properties (carbon to nitrogen ratio, nutrients content etc.) of the
initial mixture in such manner as to the promote microbiological activity.
5.1.3. Pretreatment and preparation of the composting raw material
The sugar beet leaves were shredded to size 2 to 4 cm using a commercial shredder
type MTD 118E prior its supply into the bioreactor. After the green material had been
shredded it was then weighted and packed ready to be used. The primary sludge was
also weighted and packed ready to be used. The weighted and packed raw materials
were then mixed manually using shovels and ready to be fed into the bioreactor.
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