Maintenance strategies and local impact of MSW incinerators

The present paper gives a contribution to the understanding of the effects of variations in maintenance scheduling on the environmental impact of municipal solid waste incinerators. The proposed approach allows a vision of their impact beyond the conventional balances. The characteristics of a selected case study were put forward and discussed. A plant proposed for a region in the North East of Italy was chosen for the scheduling effects analysis because of the long period of non-operation of each waste treatment line: 3 months per year as requested from the local environmental protection agency. The following effects were discussed on a yearly basis: maintenance stop fractionation, maintenance stop lasting, maintenance stop seasonal scheduling; the last aspect was discussed also at device level. The extreme scenario of seasonal stop gave the opportunity of assessing the highest reduction of yearly average impact from the stack, varying the season of maintenance: a reduction up to 23% could be obtained for the pollutants concentration contribution at ground level in the area of highest impact, comparing the worst case with the best case by a diffusive model. In the case of more common periods of stops for maintenance the reduction would be lower. The role of district heating must be taken into account too.