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

educed and on the 18 th day ammonium concentration was 613.79mg/L. Nitrates in
leachates presented a significant increase throughout the duration of the 2 nd trial. On
the 3 rd day their concentration was limited at 31.73mg/L while on the 18 th day it has
been increased approximately 14 times reaching at 442.51mg/L. Table 20 shows also
that heavy metals such as Cd, Cr, Cu, Ni, Pb and Zn were present in leachates
throughout the process. The metal concentrations were much below the indicative
values for wastewater disposal as shown in Table 7.
According to BOD 5 , ammonium and nitrates values obtained for the leachates of the
2 nd composting trial it can be concluded that leachates had a heavily polluted organic
and inorganic load which needs to be treated before its final disposal. The quantity of
leachates production during the 2 nd trial was limited and stored to an impermeable
reservoir for sufficient period of time to be stabilized at lower values through aeration.
Although composting can be assessed for sludge treatment and reuse through land
application, leachates remain an environmental problem since the treatment of solid
waste through composting results in transferring the problem from solid to liquid
phase. Leachates must be treated accordingly in order to be disposed to a water
recipient based on the suggested standards shown in Table 7. However Directive
91/271/EEC seeks to harmonise measures relating to the treatment of wastewater at
Community level in order to protect the environment from any adverse effects due to
discharge of such waters.
5.2.8. Removal and collection of the composting end product
The removal and collection of compost was perfomed on the 23 rd day of the
composting process through the removal portals that are situated at the bottom part of
the bioreactor. To facilitate the discharge of the end product the agitation system was
operated for small intervals. The compost was collected manually using shovels and it
was spreaded in an open area outside the building where the bioreactor is installed
where it remained for five days to further reduce its moisture content (during that time
the end product was regularly agitated manually). Finally the compost was stored in
order to be used to the open field experiments.
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