Agriculture Reference
In-Depth Information
Table 11.5
Comparison of composting methods. (Source: Parsons (
2002
))
Aerated static pile
Windrow
In-vessel
Highly affected by weather
(can be lessened by covering,
but at increased cost)
Highly affected by weather
(can be lessened by covering,
but at increased cost)
Only slightly affected by
weather
Extensive operating history
both small and large scale
Proven technology on small
scale
Relatively short operating
history compared to other
methods
High biosolids to bulking
agent ratio so less volume
of material to handle at each
stage
Large volume of bulking agent
required, leading to large
volume of material to handle
at each stage (including final
distribution)
Large volume of bulking agent
required, leading to large
volume of material to handle
at each stage (including final
distribution)
Adaptable to changes in
biosolids and bulking agent
characteristics
Adaptable to changes in
biosolids and bulking agent
characteristics
Sensitive to changes in char-
acteristics of biosolids and
bulking agents
Wide-ranging capital cost
Low capital costs
High capital costs
Moderate labor requirements
Labor intensive
Not labor intensive
Large land area required
Large land area required
Small land area adequate
Large volumes of air to be
treated for odor control
High potential for odor genera-
tion during turning; difficult
to capture/contain air for
treatment
Small volume of process air
that is more easily captured for
treatment
Moderately dependent on
mechanical equipment
Minimally dependent on
mechanical equipment
Highly dependent on mechani-
cal equipment
Moderate energy requirement
Low energy requirements
Moderate energy requirement
(NRAES)
1992
). This system can control air flow and temperature by using metal
or plastic tanks or concrete bunkers in which, with the principles of a “bioreactor”
usually, the air circulation is metered via buried tubes that permit fresh air to be
injected below pressure, with the exhaust being extracted through a bio-filter, with
temperature and moisture conditions monitored using probes in the mass to allow
upholding of most favorable aerobic decomposition situation (Table
11.5
).
11.3.3
Co-composting of Oil Palm Waste
Co-composting is one of the important bio-waste treatments in the palm oil zero
waste. However, improper conditions of composting may cause several problems,
such as gas emission, bad odor, low quality product, production delay and high
handling cost. Enhancing the efficiency of waste composting becomes a vital issue
to overcome these problems (Yeoh et al.
2011
). Numerous amendments have been
formed for improvement in the composting mechanism, enhancing rate of degrada-
tion and compost quality to obtain about 30 C/N ratio (Costa et al.
1992
), this is
commonly known as co-composting.
Co-composting process has been performed using partially treated POME with
EFB (Baharuddin et al.
2009
). Produced compost had sufficient contents of some
