Environmental Performance in the Production and Use of Recovered Fertilizers from Organic Wastes Treated by Anaerobic Digestion vs Synthetic Mineral Fertilizers

Abstract

Recovered fertilizers (RFs), in the form of digestate and digestate-derived ammonium sulfate, were produced from organic wastes by thermophilic anaerobic digestion (AD) at full scale. RFs were then used for crop production (maize), substituting synthetic mineral fertilizers (SFs). Environmental impacts due to both RF and SF production and use were studied by a life cycle assessment (LCA) approach using, as much as possible, data directly measured at full scale. The functional unit chosen was referred to as the fertilization of 1 ha of maize, as this paper intends to investigate the impacts of the use of RF (Scenario RF) for crop fertilization compared to that of SF (Scenario SF). Scenario RF showed better environmental performances than the system encompassing the production and use of urea and synthetic fertilizers (Scenario SF). In particular, for the Scenario RF, 11 of the 18 categories showed a lower impact than the Scenario SF, and 3 of the categories (ionizing radiation, fossil resource scarcity, and water consumption) showed net negative impacts in Scenario RF, getting the benefits from the credit for renewable energy production by AD. The LCA approach also allowed proposing precautions able to reduce further fertilizer impacts, resulting in total negative impacts in using RF for crop production. Anaerobic digestion represents the key to propose a sustainable approach in producing renewable fertilizers, thanks to both energy production and the modification that occurs to waste during a biological process, leaving a substrate (digestate) with high amending and fertilizing properties.

A Critical Review of Data Science Applications in Resource Recovery and Carbon Capture from Organic Waste

“…Studies that assessed the environmental and economic impacts of treating liquid and solid digestate from anaerobic digestion comprised 13% of all the LCA and LCCA/TEA studies reviewed (Figure b and Table S10). LCA studies focused on biogas production from anaerobic digestion integrated with treatment of the liquid digestates to recover nutrients via struvite precipitation − and ammonia stripping , utilizing municipal sewage sludge and animal waste as feedstocks. These studies were conducted by applying CML and ReCiPe in European countries and using TRACI in the USA.…”

Environmental Forensic

“…Several LCA studies reported better environmental impacts for the agriculture use of treated sewage sludge respect chemical fertilizers (Herrera et al, 2022;Di Maria et al, 2016;Chiew et al, 2015;Tidåker et al, 2006;Suh and Rousseaux, 2002;Hareder et al, 2017;Hospido et al, 2005;Brockmann et al, 2018;Muñoz et al, 2017;Chiu et al, 2016).…”

Pilot-scale evaluation of the sustainability of membrane desalination systems for the concentrate volume minimization of coal chemical wastewater

“…High fluxes (50-100 L m −2 h −1 (LMH)) occurred when VSEP was used to control the deposition of colloidal silica on the membrane surface. 11 VSEP has already been commercialized in recovering nutrient concentrate from pig slurry 12 and reducing magnetic ion exchange concentrate volume. 13 DTRO has a plate-andframe configuration with large feed channels and a shorter flow path, which creates high turbulence, thus alleviating the membrane fouling potential.…”