Measuring ammonia and odours emissions during full field digestate use in agriculture

Using highly stabilized digestate and digestate-derived ammonium sulphate to replace synthetic fertilizers: The effects on soil, environment, and crop production

“…The digestate used in this work derives from anaerobic digestion of sewage sludge, while ammonium sulphate used in RF treatment was obtained by ammonia stripping during the same anaerobic digestion process. The details of the process to produce fertilizers and their characteristics have been widely described and discussed in previous work (Pigoli et al, 2021;Zilio et al, 2021); fertilizer data are reported in Tables S1 and S2. The digestate in particular showed a high biological stability (BMP: 89 ± 17 Lbiogas kg -1 dw) compared to other agricultural digestates (Pigoli et al, 2021).…”

“…To transform these biomasses into products which can be utilised in agriculture, technological/biotechnological treatments are therefore necessary (Sigurnjak et al, 2019). Among these treatments, in recent decades the anaerobic digestion process has been proposed as a valid technology to valorise organic wastes of different types, producing biogas, and also as a source of biofertilizers such as digestate which can be used in agriculture as a substitute for synthetic fertilizers (Pigoli et al, 2021;Tambone et al, 2019;Verdi et al, 2019;Zilio et al, 2021).…”

“…Furthermore, originating from organic wastewater and organic wastes, digestate also has the same problems of contamination by heavy metals, pathogens and organic pollutants typical of these biomasses, which could therefore pollute the soil (Govasmark et al, 2011). Although progressively more studies in recent years are shedding additional light on the safety of digestates for agricultural use, as well as on the best process methods and accurate selection of feedstock, there are still only very limited data available on the impacts that the use of these biomasses have on full scale agriculture in the field (Koszel and Lorencowicz, 2015;Pigoli et al, 2021;Verdi et al, 2019;Zilio et al, 2021).…”

The Potential of Digestate and the Liquid Fraction of Digestate as Chemical Fertiliser Substitutes under the RENURE Criteria

“…The median and upper values for N min (Table 3) would suggest a gross potential from digestate as substitute to Haber-Bosch-derived chemical N-based fertilisers of approximately 4 to 18% (excluding ammonia volatilisation and NFRV), thereby also decreasing the high energy consumption and carbon dioxide emissions associated with the process. Precision injection techniques have been shown to reduce ammonia (NH 3 ) losses; therefore, subtracting a mean approximate value of 10% of the total ammoniacal nitrogen, if precision injection were to be used [51,70], would lead to a corrected estimate ranging from 3 to 16% of total N min consumption. Factoring in a replacement value of 82%, which was the average NFRV associated with the 90% to 100% N min /TN pool in the RENURE metanalysis [12], would theoretically result in a gross N substitute value of 3 to 13% (assuming all digestates meet the RENURE criteria).…”

Sewage Sludge as N-Fertilizers for Crop Production Enabling the Circular Bioeconomy in Agriculture: A Challenge for the New EU Regulation 1009/2019

“…The use of organic fertilizers has enhanced the sustainability of agricultural production, decreasing the need for non-renewable resources and the environmental impact of agriculture [8]. For instance, it was recently reported that anaerobic digestate can replace urea as a fertilizer in agriculture without increasing ammonia emissions and reduces the risk of soil and water pollution [9,10].…”