Anaerobic digestion of sulfate-acidified cattle slurry: One-stage vs. two-stage. (15th May 2016)

• Record Type: Journal Article
• Authors: Moset, Veronica; Ottosen, Lars Ditlev Mørck; Xavier, Cristiane de Almeida Neves; Møller, Henrik Bjarne
• Is Part Of: Journal of environmental management. Volume 173(2016)
• Page Start: 127
• Page End: 133
• Publication Date: 2016-05-15
• Subjects: Anaerobic digestion -- Two-step continuous stirred tank reactors -- Sulfate-acidified slurry; AcCM acidified cattle manure -- CH4 methane -- CM cattle manure -- CO2 carbon dioxide -- CSTR continuous stirred tank reactor -- H2S hydrogen sulfide -- H2SO4 sulfuric acid -- NH3 ammonia -- PR pilot reactor 100 L total capacity -- PR1 control pilot reactor 100 L total capacity fed cattle manure and working at 50 °C -- PR2 one stage pilot reactor 100 L total capacity fed with mixture of acidified and non-acidified cattle manure and working at 50 °C -- PR3 pilot reactor (100 L total capacity) used as second step of a two stages anaerobic digestion -- R65 laboratory reactor with 20 L working capacity working at 65 °C used as first step of a two-stage anaerobic digestion -- SRB sulfate-reducing bacteria -- TAN total ammonia nitrogen -- TS total solids -- VFA volatile fatty acids -- VS volatile solids -- VSc corrected volatile solids; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2016.02.039
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Two strategies to include acidified cattle manure (AcCM) in co-digestion with normal cattle manure (CM) are presented in this work. The strategies are a single thermophilic (50 °C) continuous stirred tank reactor (CSTR) anaerobic digestion and a two-step (65 °C + 50 °C) CSTR process. In both strategies, two different inclusion levels of H2 SO4 -acidified CM (10% and 20%) in co-digestion with normal CM were tested and compared with a control CSTR fed only CM. Important enhancement of methane (CH4 ) yield and solid reductions were observed in the thermophilic one-step CSTR working with 10% AcCM. However, a higher inclusion level of AcCM (20%) caused volatile fatty acid accumulation in the reactor and a more than 30% reduction in CH4 production. In terms of CH4 production, when 10% of AcCM was co-digested with 90% of CM, the two-step anaerobic co-digestion yielded less than the single step. During the first step of the two-step CSTR process, acidogenesis and a partial sulfate reduction were achieved. However, sulfide stripping between the first and the second step must be promoted in order to advance this technology. Highlights: Two inclusion levels of sulphate acidified cattle manure were digested. One-step and two-steps anaerobic digestion of acidified manures were compared. 10% acidified manure promoted methane yield, 20% caused process inhibition. During the first step, acidogenesis and a sulfate reduction were achieved. Sulfide stripping after the first step must be promoted.