The following table compares the ATD Manure Treatment System
with two commonly used manure treatment systems: anaerobic digesters and
composting.
| |
ATD System |
Anaerobic Digesters |
Composting |
| Manure Flow |
Barn to Plant to Pellet
storage with liquids recycled to Barn. |
Barn to Digester to Lagoon
to land unless full treatment systems are added to separate and dry
solids for pellets and treat water for recycling. |
Barn to separator with
liquids to lagoon and land and solids to mixer for addition of carbon
and structure then to land. |
| |
| Process Time |
1 day. |
Must be designed for
digester residence time of many days, additional treatment would be
sized accordingly. Otherwise lagoons subject to annual pumpout. |
Solids will take 45
to 60 days depending on management and weather. |
| ^
top |
| Water Consumption |
3.7 Litres per day per
place. |
22.1 Litres per day per
place (assuming 2.7% solids in pumpout) or for 10,000 places, 150,000
Litres per day. |
22.1 Litres per day per
place (assuming 2.7% solids in pumpout) or for 10,000 places, 150,000
Litres per day. |
| ^ top |
| Odours |
Off floor evaporation
only remaining source. Eliminates Hydrogen Sulfide and Ammonia. |
Somewhat reduced. |
Somewhat reduced if managed intensively. |
| ^ top |
| |
ATD System |
Anaerobic Digesters |
Composting |
| Greenhouse Gases |
Reduced by over 65%. |
Methane burning reduces
greenhouse gas release. |
Active management can
reduce ammonia release from solids. |
| ^ top |
| Disposal Acreage |
As surplus pellets can
be sold off-site the opportunity for re-balancing nutrients to available
land can be achieved with the least disruption. As regulators focus
on these issues, the ability to export any surplus will allow new
choices to be made. It is now possible to expand to obtain economies
of scale on the same land base. |
Unless additional treatment
is installed the equations remain the same. |
No change. |
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| Nutrient Management |
N losses as high as 70%
can be eliminated. Phosphorus is all in the pellet. Surplus nutrients
can be sold off-site as a dry, pathogen free pellet with consistent
analysis. |
Methane burning in itself
has no effect on N,P,K. Inconsistent and lower nutrient levels continue
with lagoon pumpouts. Surplus nutrients will still require additional
treatment. |
The more volatile nutrients
are stabilized in the solids and the liquids retain dissolved nutrients
as before. |
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| Value Added Byproduct |
Surplus nutrients in
pellets, greenhouse gas reductions. |
Electricity Greenhouse
gas reductions. |
Surplus compost. |
| ^ top |
| |
ATD System |
Anaerobic Digesters |
Composting |
| Pathogens,Weedseed |
Both liquids and solids
are pathogen free and weed seeds are infertile. |
No change unless additional
treatment is added. |
Liquids are untreated
and a well managed compost with sufficient heat will kill the weed
seeds. |
| ^ top |
| Site Requirements |
A building 100' by 50'
located somewhere along the present route to the lagoon would allow
new plumbing arrangements to be made conveniently. Three phase power
and reliable telecommunications will be needed. This is a chemical/mechanical
process having no biological treatment component affected by weather.
It is computer assisted and remotely monitored to ensure trouble free
operation. Certificates are not required by staff for operation. |
The digester should
be located between the barns and the existing lagoon if possible.
Connections will be needed to the power grid. Heat losses over the
winter months are a consideration. If additional processing is added
to close the loop on water quality and dried pellets then the site
should be large enough to take these additions at some point. |
The compost piles may
need cover and will need sufficient room for 60 days retention. A
pad may be required for leachate control. |
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| Bottom Line |
The effect on costs will
be the difference between current expenditures and new system expenditures.
ATD offers to review these with potential clients to determine the
benefits before commitments are made. |
It would appear that
the costs of the digester and generating equipment less the power
savings, power sales and heat consumption must be isolated as a separate
issue. The issues of the lagoons, odour and nutrient balance remain
until additional treatments are added. |
Compost holds more water
than pellets and thus adds to hauling costs when exported. The nutrient
levels may not be consistent and the market for the product may be
elusive. |
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