Environmental impact and occupational risk in gasification plants processing residues of sewage sludge and refuse-derived fuel: a review

Scope & Goals: This article reviews recent scientific reports on environmental impact, as well as occupational safety and health, of gasification plants using residues of sewage sludge and refuse-derived fuel. Methods: The survey, covering a 10-year time span, was made through a typical systematic review of the literature, retrieved from online databases of scientific publications and by using general search engines; cross-referencing of citations included in documents was also considered. Results: Two tables summarising 38 publications were created, indicating relevant studies on the selected topics and providing a short description on risks, goals and main findings of each study, followed by a general discussion. Conclusions: Overall, gas explosion and inhalation of toxic gases were the most common risks reported in published studies, being considered negligible if safety measures are adopted; however there are fewer studies focusing on occupational safety in gasification plants than those focused on environmental hazards. Release of heavy metals, tar production and toxic gases are the main environmental concerns. From the prevention viewpoint, this review shows that treatment and valorisation of harmful tars is key feature that must be improved in the future to enable a sustainable development of this technology at a commercial scale.