Evaluation of best technologies for the removal of unwanted elements in an industrial air flow.

This thesis addresses the challenge of controlling Volatile Organic Compounds (VOCs) emitted from wastewater treatment processes at the Villastellone facility of the Marazzato Group. The current abatement strategy, based on low-temperature thermal oxidation, entails high fuel consumption and limited efficiency, highlighting the need for more sustainable solutions. To this end, a pilot-scale unit was designed and tested, based on activated carbon adsorption with in situ steam regeneration and subsequent post-combustion of desorbed VOCs. The research pursued three main objectives: (i) to characterize the adsorption performance of the carbon bed through breakthrough curves, mass-transfer zone analysis and regeneration efficiency; (ii) to perform a multi-criteria decision analysis (MCDA), comparing the pilot system with established alternatives – regenerative thermal oxidizers (RTOs), wet scrubbers and catalytic oxidizers – using AHP and TOPSIS methodologies across technical, economic, environmental and operational criteria; (iii) to carry out an occupational risk assessment according to the DVR framework, identifying major hazards (thermal, chemical, explosion/fire, electrical, mechanical) and defining mitigation measures and standard operating procedures. Experimental results demonstrated VOC removal efficiencies above 98% and recovery of 80–90% of the carbon’s adsorption capacity after each regeneration cycle. Energy analysis confirmed competitive consumption compared with thermal systems, with a favorable steam-to-VOC ratio. The MCDA ranked the pilot system and wet scrubbers as the most balanced options, while RTOs retained their role as technical benchmarks but were penalized by higher costs and energy demand. Catalytic oxidizers showed intermediate performance, limited mainly by catalyst deactivation risks. The safety analysis highlighted VOC exposure and thermal hazards as high-priority risks, mitigable through engineering interlocks, fire-suppression systems, personal protective equipment, and codified operating procedures. Overall, the study confirms the technical feasibility and environmental–economic sustainability of steamregenerated activated carbon for VOC abatement. The findings provide the Marazzato Group with operational recommendations for potential scale-up to full industrial capacity, while identifying future research needs related to carbon aging phenomena, energy optimization and integration with advanced monitoring and control systems.