Organic micropollutants, heavy metals and pathogens in anaerobic digestate based on food waste. (1st July 2022)

• Record Type: Journal Article
• Authors: Golovko, Oksana; Ahrens, Lutz; Schelin, Jenny; Sörengård, Mattias; Bergstrand, Karl-Johan; Asp, Håkan; Hultberg, Malin; Wiberg, Karin
• Is Part Of: Journal of environmental management. Volume 313(2022)
• Publication Date: 2022-07-01
• Subjects: Biofertilizer -- Food waste -- Risk assessment -- Heavy metals -- CECs; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2022.114997
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Anaerobic digestate based on food waste is increasingly used as fertilizer in food production. This study examined the characteristics of anaerobic digestate based on food waste from three biogas plants in Sweden. The characterization included measurements of heavy metals ( n = 7), chemicals of emerging concern (CECs), such as currently used drugs and pesticides ( n = 133), and an extended range of food-borne pathogens, including two notable sporeformers and some widespread antibiotic-resistant bacteria. The amounts of Escherichia coli, enterococci, and Salmonella and the concentrations of the target heavy metals were all below the maximum accepted levels at all three locations studied. However, the spore-forming Bacillus cereus was found to be present at high levels in samples from all three biogas plants. Among the 133 CECs investigated, 48 were detected at least once, and the highest concentrations were found for pyroxidine, nicotine, caffeine, theobromine, and nicotine. The biofertilizers from the different biogas plants had similar CEC profiles, which indicate similarities in household waste composition and thorough mixing in the biogas plants. If this profile is found to be spatially and temporally consistent, it can help regulators to establish priority lists of CECs of top concern. Assuming increasing use of biofertilizers for food production in the future, it would be beneficial to have concentration limits for CECs Risk estimation based on risk quotients (RQs) indicated generally low environmental risks associated with application of biofertilizer to soils for food crop production. However, the toxicity of CEC mixtures needs to be considered when estimating the risks from application of biofertilizers on agricultural land or in other production systems. Graphical abstract: Image 1 Highlights: Risk factors (CECs, pathogens, heavy metals) in biofertilizer based on food waste. Food-borne pathogens and heavy metals were below the maximum accepted levels. For CECs, 133 compounds were analyzed and 48 CECs were detected. Highest concentrations were found for pyroxidine, nicotine, caffeine, theobromine. The CEC profile was similar in biofertilizers from different biogas plants.