Organic Waste Recycling

Composting 115

Figure 3.10 The Vietnamese composting toilet (Rybczynski et al. 1978; reproduced by
permission of the International Development Research Centre, Canada)

3.6.2 Off-site composting

Because of large quantities of organic wastes to be decomposed, off-site
composting should employ aerobic reactions to shorten the composting period
and reduce the size of composting plants. Some of the aerobic composting
systems currently in operation are:

Chinese ground-surface aerobic composting pile

As shown in Figure 3.11, the compost feed (a mixture of human or animal
manure and vegetable matters) is piled up into a heap of approximately 2 x 2 x
0.5 m (length x width x height). The compost heap is inserted with perforated
bamboo poles to facilitate natural aeration and provide a kind of structural
support, and no turning of the compost pile is required. To control excessive
heat loss, the compost pile is covered with rice straw or a plaster of mud (Figure
3.12). The poles can be removed after 1 or 2 days when the mud has hardened or