Converting Waste Agricultural Biomass into a Resource - UNEP

Figure 2. Hopper or Feeder
The composting technology starts with the hopper or feeder where the bulk
and sacked vegetable wastes from the market are all dropped before being
crushed by the crusher. A belt conveyor catches and slowly transmits
horizontally the slightly crushed vegetables into the shredder. One personnel
applies the dry mass to the vegetable wastes, becoming the primary
substrates for composting, while being transported to the hopper of the
shredder. The dry mass is intended to (1) absorb moisture from the vegetable
wastes, since
80-90% of the wastes’ composition is liquid, and (2) create a balance between
the nitrogen and carbon elements. The shredder further breaks the substrates
into smaller pieces to expose more surface area for decomposition. Shredded
substrates are hauled into the mixer by the screw conveyor linked between
the two.
Figure 3. Enhanced microorganisms are added to hasten digestion
An inoculant, enhanced microorganisms released from a supply tank on top of
the mixer, is fused with the substrates resulting to secondary substrates to
hasten digestion. These secondary substrates are now ready for the aerobic
process of composting. The substrates exit the mixer and are brought up to
the silo through a bucket conveyor. All equipment is run by a three-phase
electrical layout. In usual practice for a silo-based composting, peak of
decomposition usually takes a minimum of 30 days to be fully composted (for
thermophilic phase). With this in mind, the silos, intended to take care of the
volume requirement of vegetable wastes and space considerations, are
designed also to shorten the decomposition time and control the temperature
for composting vis-à-vis the Baguio climate. It is projected to a 20 to 25 days
decomposition time only, ready for curing and maturity stage before sieving
and packaging. Although the composting plant produces a competitive
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