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

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5. Humification indicators – measurement of humic substances, especially
humic acid carbon to fulvic acid carbon ratio, may provide an effective measure
of stabilization. Humic acid content increases as composting progresses.
6. Molecular size determination – molecular sizes rise as humic substances
are formed. This test requires specialized equipment <strong>and</strong> expert operators.
(Composting Council of Canada., 2010)
2.1.5. Composting process cost
Composting costs include costs that have to do with local criteria, facility
operations <strong>and</strong> marketing of the finished product. The facility must be installed
in a region according to each country’s laws in a way that public health is not
damaged at any means. There may be some more requirements something that
depends on the whole compost facility design such as h<strong>and</strong>ling equipment such
as shredders, screens, conveyers <strong>and</strong> turners. The cost of constructing <strong>and</strong>
operating a windrow composting facility will vary from one location to another.
The operating costs depend on the volume of material processed. The use of
additional feed materials, such as paper <strong>and</strong> mixed municipal solid waste,
which will require additional capital investment <strong>and</strong> materials processing labor.
(Aarhus University., 2004)
The capital costs of windrow or aerated piles are considered to be lower in than
in-vessel composting systems. However, the potential cost of the facilities could
increase remarkably when cover <strong>and</strong> other mechanisms are required to control
odors. In most of the cases though costs of windrow systems are the lowest
compared to the other two techniques. Basically In-vessel system costs more
than the other methods, mainly because it is more mechanized <strong>and</strong> more
equipment maintenance is necessary, however the labor intensive trend’s to be
less. (EPA., 1994).
2.1.6.Environmental <strong>and</strong> health impacts
Composting is mainly used as high quality soil in agriculture. This practice
prevents other chemical substances which have been used in the past <strong>and</strong> are
dangerous, to be used as a fertilizer for soil improvement. The negative impacts
of composting are dangerous gases emissions (Figure.7) such as: greenhouse
gases (GHGs), volatile organic compounds (VOCs) <strong>and</strong> odors. In order for the
composting process to be effective these gases have to be controlled. In soils
<strong>and</strong> water systems the major concerns are due to deposition of salts <strong>and</strong> heavy
metals.