Sludge combustion might be a solution?

Sludge combustion in mono-incineration plants remains a valid option for sludge disposal when recycling in agriculture is impaired by legislation, not allowed by local authorities or when sludge characteristics would be not suitable for its use on land. Moreover, in many heavily urbanized areas, large quantities of sewage sludge would require considerable extension of land often not available in the surroundings of the WWTP and sludge should be managed in an alternative way in winter, when sludge spreading is forbidden, since storage would need prohibitive volume.