COMPOSTING OF MUNICIPAL SOLID WASTE (MSW): ANAEROBIC VS AEROBIC
Abstract
Introduction. Pilot plant study of anaerobic composting of the organic fraction of municipal solid waste (MSW) in Isfahan was performed using sequential batch system. The anaerobic composting were compared with the conventional aerobic composting of MSW using windrow system in 1998-99.
Methods. An experimental study was performed on samples of household refuses, anaerobic composts, aerobic composts and leachate of anaerobic composts. Inert materials, heavy metals concentration and physical characteristics of anaerobic and aerobic composts were compared.
Results. There was not significant difference between physical and chemical characteristics of anaerobic and aerobic composting. The study showed that the heavy metals concentration in the anaerobic compost was less than aerobic compost and inert materials in both composts were more than standard concentration.
Discussion. Sequential batch anaerobic composting (SEBAC) system is stable and has a good flexibility for organic materials with high total solids and a good way for MSWs composting. Amounts of heavy metals (e.g. Pb, Zn, Cu, Ni, Cr, Fe, Cd) in compost of the separated municipal solid wastes were low and about the standard ranges, but in the compost of unseparated MSWs were significantly higher than standard compost (P < 0.05). Therefore, separating the municipal solid waste in houses is essential for conservation of agricultural soil pollution.
Methods. An experimental study was performed on samples of household refuses, anaerobic composts, aerobic composts and leachate of anaerobic composts. Inert materials, heavy metals concentration and physical characteristics of anaerobic and aerobic composts were compared.
Results. There was not significant difference between physical and chemical characteristics of anaerobic and aerobic composting. The study showed that the heavy metals concentration in the anaerobic compost was less than aerobic compost and inert materials in both composts were more than standard concentration.
Discussion. Sequential batch anaerobic composting (SEBAC) system is stable and has a good flexibility for organic materials with high total solids and a good way for MSWs composting. Amounts of heavy metals (e.g. Pb, Zn, Cu, Ni, Cr, Fe, Cd) in compost of the separated municipal solid wastes were low and about the standard ranges, but in the compost of unseparated MSWs were significantly higher than standard compost (P < 0.05). Therefore, separating the municipal solid waste in houses is essential for conservation of agricultural soil pollution.
Keywords
COMPOSTING, MUNICIPAL SOLID WASTE, ANAEROBIC COMPOSTING, AEROBIC COMPOSTING, ISFAHAN