Evaluating an anaerobic digestion (AD) feedstock derived from a novel non-source segregated municipal solid waste (MSW) product.
In many nations industrial scale AD of non-agricultural waste materials (such as MSW) has not yet reached its full potential, often constrained by the lack of secure, inexpensive, high quality AD feedstocks, and markets for the resulting digestate material. We tested the output material of a high throughput novel industrial process to define its potential as an AD feedstock (based on quality and consistency). This process, designed to circumvent the constraints of source segregation while still generating segregated waste streams, resulted in the production of a temporally homogenous fibrous material with: an average moisture content of 44.2 (±2.33)%; C:N ratio of ∼32.9:1 (±3.46:1), C:P ratio of ∼228:1 and gross calorific value of 17.4 (±0.29)MJ/kg(DM). This material provided a CH4yield of between 201 and 297m3CH4/tonne(DM)(271-401m3CH4/tonne(vs)) comparable to commonly used AD feedstocks. Material contaminant levels were temporally consistent (P>0.05), (average values being Cd 0.63 (±0.19), Cu 56.3 (±7.45), Crtot51.4 (±4.41), Hg<0.3, Ni 28.9 (±5.17), Pb 79.2 (±23.71), Zn 202 (±44.5), total polyaromatic hydrocarbons (PAH) 2.2 (±0.3), and total polychlorinated biphenyls (PCB) (<0.2)mg/kg(DM)). Calculated digestate contaminant levels were below the median contaminant threshold limits for anaerobic digestates of all countries within the European Union i.e. of Cd 3.35, Cu 535, Crtot535, Hg 8.15, Ni 185, Pb 397.5, Zn 2100mg/kg(DM). We suggest that novel high throughput processes that produce high quality AD feedstocks, may have a place in further diversion of waste from landfill.
Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne, UK.
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Blake
Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne, UK.
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Halim
Graphite Resources Ltd, Higham Place, Newcastle upon Tyne, UK.
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Gray
Graphite Resources Ltd, Higham Place, Newcastle upon Tyne, UK.
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Mair
Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne, UK.
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Manning
Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne, UK.
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Sallis
Durham University, School of Engineering and Computing Sciences, Durham, UK.
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Hutchinson
Newcastle University, School of Civil Engineering and Geosciences, Newcastle upon Tyne, UK. Electronic address: N.D.Gray@ncl.ac.uk.
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Gray
D000693:Anaerobiosis; D056804:Biofuels; D002947:Cities; D004926:Escherichia coli; D005060:Europe; D005740:Gases; D008697:Methane / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D012475:Salmonella; D012987:Soil; D062611:Solid Waste; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D064091:Waste Disposal Facilities
D056804:Biofuels; D005740:Gases; D012987:Soil; D062611:Solid Waste; D008697:Methane
Anaerobic digestion feedstock; Municipal solid waste; Regulation of waste; Roto-autoclaving; Sustainable biogas production; Waste treatment