Improvement of the Composting Process

Improvement of composting efficiency is still an important research topic. Several authors have tried to define the optimal temperature for composting (Waksman et al., 1939; Jeris and Regan, 1973; Suler and Finstein, 1977). It is often assumed that thermophilic organisms are more efficient than mesophiles. Schulze (1962) showed that it is possible to maintain a composting process continuously in the thermophilic phase. Ventilation induced through temperature feedback system (Rutgers strategy) shows a higher decomposition rate than fixed ventilation (Beltsville strategy) (MacGregor et al., 1981). Blower operating either to pull or push air into the pile (Haug, 1980), drawing air from the base or the core of the pile (Mercedes et al., 1994) and the recirculation of the air in a reactor (Miller et al, 1990) have been tried to reduce the heterogeneous conditions common to piles. The aim of the present research is to compare the conversion of dry matter under self-heating conditions (with a preset temperature limit) with composting at the optimal temperature.