(best examples and good practices) on household organic waste ...

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The wastes used for the anaerobic digestion process differ between regions
according to the type of agricultural production. These could be human <strong>and</strong>
animal wastes, <strong>and</strong> agricultural by-products such as grain stalks (primarily
rice), sweet potato vines, <strong>and</strong> weeds. The basic (AD) household reactors
comprise of a cylinder (Picture 73.) shaped main reactor with a domed top.
Waste material is fed into the reactor through a port that is connected into the
bottom of the reactor.
Picture 73.: Household (AD) under construction
Nowadays these reactors have been developed. The effluent chamber <strong>and</strong>
reactor are connected, <strong>and</strong> generally, toilets <strong>and</strong> pigsties are connected directly
to the influent port something that didn’t happen earlier. The effluent is
removed from the reactor at the top of the water column. Thus supernatant is
collected rather than sludge. Additionally, no mixing of the system occurs when
effluent is removed. In some systems, a vertical cylindrical pull-rod port is
added at the side of the effluent port. The pull-rod port connects into the base
of the effluent port. Effluent is removed by moving a pull-rod up <strong>and</strong> down in
the port. The pull-rod is simply a wooden shaft with a metal disk on the
bottom. In addition to simplifying effluent removal, as a bucket can be placed
directly under the pull-rod port, removing the effluent provides some mixing in
reactor. In the st<strong>and</strong>ard reactor design, the head space volume above the
reactor is essentially fixed, although the volume increases slightly with
increasing pressure since the effluent port liquid level moves up <strong>and</strong> down with
pressure changes. If in any case effluent is not removed from the AD system,
the of it volume in the reactor <strong>and</strong> the head space volume is reduced. As a
result, gas pressure delivered into the home varies. (Henderson.,2010)
The construction of these reactors is made by experienced local technicians
trained by the Country for this job. (Picture 74.)