title: A greenhouse-scale photosynthetic microbial bioreactor for carbon sequestration in magnesium carbonate minerals.
abstract: A cyanobacteria dominated consortium collected from an alkaline wetland located near Atlin, British Columbia, Canada accelerated the precipitation of platy hydromagnesite [Mg5(CO3)4(OH)2·4H2O] in a linear flow-through experimental model wetland. The concentration of magnesium decreased rapidly within 2 m of the inflow point of the 10-m-long (∼1.5 m(2)) bioreactor. The change in water chemistry was monitored over two months along the length of the channel. Carbonate mineralization was associated with extra-cellular polymeric substances in the nutrient-rich upstream portion of the bioreactor, while the lower part of the system, which lacked essential nutrients, did not exhibit any hydromagnesite precipitation. A mass balance calculation using the water chemistry data produced a carbon sequestration rate of 33.34 t of C/ha per year. Amendment of the nutrient deficiency would intuitively allow for increased carbonation activity. Optimization of this process will have application as a sustainable mining practice by mediating magnesium carbonate precipitation in ultramafic mine tailings storage facilities.
authors: Department of Earth Sciences, The University of Western Ontario , London, Ontario N6A 5B7, Canada.
authors: Jenine
authors: J
authors: McCutcheon
authors: Ian M
authors: IM
authors: Power
authors: Anna L
authors: AL
authors: Harrison
authors: Gregory M
authors: GM
authors: Dipple
authors: Gordon
authors: G
authors: Southam
mesh_terms: D019149:Bioreactors; D001955:British Columbia; D057965:Carbon Sequestration; D000458:Cyanobacteria / Q000378:metabolism*; D007220:Industrial Waste; D008274:Magnesium / Q000378:metabolism*; D008906:Mining; D010788:Photosynthesis; D014867:Water / Q000737:chemistry
chemical_list: D007220:Industrial Waste; D014867:Water; C005479:magnesium carbonate; D008274:Magnesium