Composting
Composting is the degradation of organic
materials in an aerobic (with oxygen) environment. It
is a natural process that can be optimised by ensuring
that feedstocks are carefully mixed, watered if necessary
and turned regularly. Keenan Recycling have developed
an intensively managed regime that has achieved both
BSIPAS100 and Soil Association Organic Certified Input
accreditation.
Our large scale garden waste composting
takes place in “windrows” approximately 4m
high and 100m long. With such a large volume of material
it is possible to create a consistent product all year
round with little variation between batches. During the
composting process temperatures increases the naturally
occurring microbes go to work breaking down the organic
matter. Typically a windrow has a core temperature of
65 - 70ºcensuring
a sanitisation of the material and destroying weed seeds.The
windrows are turned weekly to ensure that it remains
oxygenated and all material has been exposed to the core
temperature.
In
Vessel Composting
All organic material
can be composted and regulations have been developed
to allow the composting of food scraps, peelings etc.
In order to compost these materials it is necessary
to use “in-vessel” composting.
Essentially, this means that the composting takes place
within an enclosed environment to optimise and continuously
monitor the process to ensure that the sanitisation criteria
are achieved. There are many different “in-vessel” systems
but all must meet strict criteria to ensure that the
waste is shred to a set particle size (to ensure heating
throughout), that processes are contained until the material
is sanitised and that a critical temperature is maintained
for a designated duration.
Keenan Recycling utilises a
vertical composting system by VCU Europa (pictured above).
This is a modular system offering flexibility and control.
Within the reception building food scraps are shred to
below 12mm and mixed with garden waste and wood chip
to create a balanced blend to optimise the composting
process. The material is then conveyed to the VCU system.
The new VCU in-vessel composting
system is capable of converting 20,000 tonnes per annum
of category 3 food waste, fish waste and commingled food/green
waste into high value compost rich in plant nutrients.
The process is similar to slow-cooking but is dependant
upon aerobic microbial activity. No other heat source
is required or allowed. If you have any of the waste
types listed above you can reduce costs by having us
recycle it rather than paying landfill costs and taxes.
It is the environmentally friendly cost effective way
to deal with food waste.
As with garden waste composting
the end product from food waste composting is a rich,
dark humus that can be used as a soil improver, however,
the addition of higher nitrogen feedstocks will increase
the fertiliser value of the compost. |
