Premium
Reducing greenhouse gas emissions and stabilizing nutrients from dairy manure using chemical coagulation
Author(s) -
Ellison Rylie J.,
Horwath William R.
Publication year - 2021
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 - 10.1002/jeq2.20195
Subject(s) - manure , effluent , liquid manure , chemistry , ferric , biogas , anaerobic digestion , organic matter , wastewater , methane , sulfate , pulp and paper industry , waste management , environmental chemistry , environmental science , agronomy , environmental engineering , inorganic chemistry , organic chemistry , biology , engineering
Two primary concerns of dairies that store manure wastewater in anaerobic ponds are greenhouse gas (GHG) emissions and unpredictable nutrient availability after applying it to forage crops. Solid–liquid separation of dairy manure wastewater with chemical coagulants significantly reduces the fraction of organic matter stored in anaerobic conditions. However, the effects of coagulants on methane emissions from ponds and nutrient availability following field application are not well understood. In this experiment, several metal salts and organic polymers were used to coagulate dairy manure wastewater for separation into solid (floc) and liquid (effluent) fractions. The coagulants tested were ferric sulfate, ferric chloride, polyaluminum chloride, Superfloc C‐569, and chitosan. An anaerobic incubation of manure effluent to simulate liquid manure storage and an aerobic incubation of manure floc‐amended soil to simulate field application were conducted with analysis of GHGs and carbon and nitrogen transformations. The treatment of chemically separating organic matter from manure wastewater effectively eliminated methane emissions under anaerobic conditions in the laboratory. In the solid manure fraction, organic carbon was stabilized in the chemically separated flocs, and, apart from flocs produced with ferric iron, nitrogen mineralization was reduced as well. Carbon dioxide emissions were also reduced from the flocs applied to soil compared with untreated manure solids.