Organic Waste Recycling

Composting 121

fans. The composting period required for this type of compost reactor ranges
from 2.5 to 5 days.

Figure 3.16 Typical temperature cross-section distributions in a pile with (a) positive
pressure (blowing) aeration; and (b) negative pressure (sucking) aeration (from Stentiford
et al. 1985; by permission of the Institute of Water Pollution Control, U.K.)

The DANO system, developed in Denmark, is presently being employed for
solid waste composting in several countries throughout the world. Although
very efficient in composting, the DANO system involves high capital and
operation costs, and requiring skillful manpower to maintain the system. Figure

Perforated pipe in duct

Perforated pipes in ducts

Insulating compost cover

< 45ºC

45 - 55ºC

55 - 65ºC

> 65ºC

KEY

(a)

(b)