EGU2020-8013, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-8013
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Effect of drying, composing and pelletizing of biowaste-based digestates on providing water soluble nutrients and stabilizing iron-cyanide (Fe-CN) complexes

Magdalena Sut-Lohmann1, Christine Knoop2, and Thomas Raab1
Magdalena Sut-Lohmann et al.
  • 1Brandenburgische Technische Universität Cottbus-Senftenberg, Lehrstuhl für Geopedologie und Landschaftsentwicklung, Cottbus, Germany (sutmagda@b-tu.de)
  • 2Stadtwerke Görlitz AG, Görlitz, Germany

With recent policy developments under the German Renewable Energies Law (Erneuerbare‐Energien‐Gesetz, EEG) and the German Waste and Recycling Law (Kreislaufwirtschaftsgesetz, KrWG) increase in organic waste utilization is expected, which can be utilized for the waste sites restoration. We present a novel application of organic amendments to reduce the mobility of iron‐cyanide (Fe‐CN) complexes and simultaneously promote vegetation. Two batches of digestates from anaerobic treatment of separately collected municipal organic waste in a two-stage semi scale biogas plant have been conditioned by a) drying, b) composting and c) pelletisation. To evaluate the influence of post-treatment of digestates on nutrient and carbon release and contaminants sorption, two batch experiments were conducted, using I) deionized water and II) potassium hexacyanoferrate (II) solution. Batch experiment I resulted in a considerably higher nutrient and carbon elution from dried digestates. Batch experiment II revealed the highest significant tot. CN conc. reduction using not composted, air dried (100%) and oven dried (82%) biowaste digestates. The FTIR analysis of dried and mortared digestate materials indicated Fe-CN complexation on inorganic (K2Mn[FeII(CN)6], NH4Fe[FeII(CN)6]) and organic constituents, and possibly formation of nitriles. In terms of rapid soil fertility enhancement and feasibility to decrease Fe-CN complexes mobility, air and oven dried fresh biowaste digestates revealed the highest efficiency.

How to cite: Sut-Lohmann, M., Knoop, C., and Raab, T.: Effect of drying, composing and pelletizing of biowaste-based digestates on providing water soluble nutrients and stabilizing iron-cyanide (Fe-CN) complexes, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8013, https://doi.org/10.5194/egusphere-egu2020-8013, 2020