Water resources recovery facilities (WRRFs) are sources of direct emissions of greenhouse gases (GHGs) and volatile organic compounds (VOCs) produced by biological processes and indirect GHG emissions due to the energy consumed to operate the plant. The direct emissions also contribute to odour issues of WRRFs. Aeration of the biological tanks accounts for 50-60% of the total energy consumption of a WRRF and is therefore the major source of indirect GHG emissions.

   The optimized management of oxidation processes is consequently associated with environmental and economic benefits. The innovative solution proposed in this study consists of an automated self-moving prototype (LESSDRONE) for real-time monitoring of oxygen transfer efficiency (OTE) and of GHG emissions from the aerated tanks during operation, and a protocol for converting LESSDRONE measures and specific WRRF data into actions aimed at minimizing carbon footprint (CF) and energy demand.

   In a non-hazardous waste landfill an integrated odour monitoring system comprised with 2 IOMS, 2 H₂S continuous analyser and two automatic air samplers has been operating since 2018: automatic air samplers are activated when two consecutive measurements of 20 ppb at 5 min intervals are measured by H₂S continuous analyser or when overall odour emission measured by IOMS exceeded 500 ouE/m³ for more than 5 min.

   Problems with odour emissions were noticed in May-August 2019 with almost a daily automatic samplers’ activation, often correlated with complaints of population; moreover, monitoring campaigns of biogas from the landfill surface showed significant increase of surface emissions for certain zones, implying that surface and fugitive emissions form landfill biogas (LFG) collecting system could have been responsible for such odour emissions. The LFG wellfield system of is comprised of a network of 301 vertical wells in the landfill, coupled with conveyance piping for the transport of LFG to energy recovery and 3 blowerflare facilities.