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Effect of Cattle Slurry Separation on Greenhouse Gas and Ammonia Emissions during Storage
Author(s) -
Fangueiro David,
Coutinho Joao,
Chadwick David,
Moreira Nuno,
Trindade Henrique
Publication year - 2008
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2007.0330
Subject(s) - slurry , nitrous oxide , ammonia , fraction (chemistry) , settling , methane , greenhouse gas , chemistry , carbon dioxide , nitrogen , environmental science , environmental chemistry , waste management , environmental engineering , chromatography , ecology , organic chemistry , engineering , biology
Storage of cattle slurry leads to emissions of methane (CH 4 ), nitrous oxide (N 2 O), ammonia (NH 3 ), and carbon dioxide (CO 2 ). On dairy farms, winter is the most critical period in terms of slurry storage due to cattle housing and slurry field application prohibition. Slurry treatment by separation results in reduced slurry dry matter content and has considerable potential to reduce gaseous emissions. Therefore, the efficiency of slurry separation in reducing gaseous emissions during winter storage was investigated in a laboratory study. Four slurry fractions were obtained: a solid and a liquid fraction by screw press separation (SPS) and a supernatant and a sediment fraction by chemically enhanced settling of the liquid fraction. Untreated slurry and the separated fractions were stored in plastic barrels for 48 d under winter conditions, and gaseous emissions were measured. Screw press separation resulted in an increase of CO 2 (650%) and N 2 O (1240%) emissions due to high releases observed from the solid fraction, but this increase was tempered by using the combined separation process (CSP). The CSP resulted in a reduction of CH 4 emissions (≈ 50%), even though high emissions of CH 4 (46% of soluble C) were observed from the solid fraction during the first 6 d of storage. Screw press separation increased NH 3 emissions by 35%, but this was reduced to 15% using the CSP. During winter storage greenhouse gas emissions from all treatments were mainly in the form of CH 4 and were reduced by 30 and 40% using SPS and CSP, respectively.