Sustainability of thermal oxidation processes: strengths for the new millennium

Incineration of sludge is occasionally accused of pollution. This paper shows that if it is correctly designed and implemented, it can be environmentally friendly. For this purpose, sludge incineration is compared to agricultural spreading of limed sludge with respect to toxicity criteria, greenhouse effect gases (GEG) release, energy wasting and other environmental parameters. Landfilling is also considered but as a standby route. Since present regulations on agricultural use and gas emission release from incinerators are stringent, incineration cannot be suspected to release more noxious substances in the environment than agriculture. A distinction is made between biogenic CO₂ and fossil CO₂. Nevertheless case studies show that incineration produces more GEG and wastes more energy than agricultural spreading if no energy is recovered from hot flue gas. In the case of thermal power or electrical power generation, the environmental balance becomes dramatically more favorable for incineration.