Composting 119Figure 3.14 Configuration of aerated piles showing construction of pile and the
arrangement of aeration pipe - the BARC system (Shuval et al. 1981; reproduced by
permission of the World Bank)
The area required for the BARC system and conventional windrow system
has been estimated to be 1 hectare (ha) per 10-12 dry tons per day of sewage
sludge. This area estimate includes: (1) area for mixing the sludge or nightsoil
with bulking materials, (2) area required for composting, (3) area required for
storage and curing piles and long-term storage before marketing, (4) area
required for screening of the final compost and separation and recycling of
wood chips, (5) area required for lagooning or waste stabilization ponds to treat
leachate and drainage from the composting area, and (6) area required for
administration, work-shops, parking of vehicles, and storage of spare parts
(Shuval et al. 1981).
A. COMPOSTING WITH FORCED AERATIONB. EXTENDED AERATED PILE