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

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Figure 7.: Principal emissions from composting
(Dubois, González., 2004)
Compost air pollution
The basic air pollutants are VOCs, CO2, CH4, NH3 <strong>and</strong> H2S (Peigne & Girardin
2004). These pollutants have a very significant cost in human life quality <strong>and</strong>
tent to destroy the atmosphere, causing severe environmental changes. The
emissions of VOCs depend on the temperature, aeration <strong>and</strong> biological activity
in the compost. The greenhouse gases CO2 <strong>and</strong> CH4 trap thermal energy that
comes to the atmosphere, rising the global temperature of the Earth (Gardner
et al. 1993,). Composting contribution to global warming due to GHGs
emissions is relatively low in comparison to other treatment methods e.g.
thermal treatment. In addition to the latter the carbon dioxide emitted to the
atmosphere during the process is assumed to be short-cycle as only biogenic
materials degrade. (Tsiliyannis., 1999).
Compost water pollution
The main pollutants of the water systems are caused by washout processes of
soils treated with compost. Therefore, the contamination of water systems
includes heavy metals, different organic compounds, e.g. phenols, PAHs, PCBs,
etc., <strong>and</strong> salts, e.g. NO3 NH4 + , etc. (He at al. 1992,; Peigne & Girardin 2004,).
Leachate production is also common. Leachate from water runoff <strong>and</strong>
condensation at compost facilities occasionally contains levels of biological
oxygen dem<strong>and</strong> (BOD) <strong>and</strong> phenols that may exceed acceptable discharge
limits, but pose few problems if absorbed into the ground or passed through a
s<strong>and</strong> filter.( Balkwaste, 2010)