TY - JOUR
T1 - Factors Controlling Microbially Induced Desaturation and Precipitation (MIDP) via Denitrification during Continuous Flow
AU - O’Donnell, Sean T.
AU - Rittmann, Bruce
AU - Kavazanjian, Edward
N1 - Funding Information:
This work was supported by the National Science Foundation Geomechanics and Geosystems Engineering and Engineering Research Center programs under grants numbered CMMI-1233658 and ERC-1449501. The authors are grateful for this support.
Funding Information:
This work was supported by the National Science Foundation Geomechanics and Geosystems Engineering and Engineering Research Center programs under grants numbered CMMI-1233658 and ERC-1449501. The authors are grateful for this support. Any opinions or positions expressed in this article are the authors only and do not reflect any opinions or positions of the NSF.
Publisher Copyright:
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2019/7/3
Y1 - 2019/7/3
N2 - Three continuous-flow column experiments were conducted to investigate the effects of nitrate loading rate and input concentrations of acetate and calcium on the effectiveness of denitrification to promote microbially induced desaturation and precipitation (MIDP). MIDP differs from microbially induced carbonate precipitation (MICP) in that it relies upon desaturation by biogenic gas production, along with carbonate precipitation, to improve the behavior of saturated granular soil. Denitrification is a stepwise process that is susceptible to inhibition and accumulation of intermediates, like nitrite, due to unfavorable chemical conditions (e.g., low pH). Therefore, nitrate reduction, nitrite accumulation, calcite saturation, and formation of carbonate precipitates were monitored in the columns. Factors investigated in these experiments included the effects of nitrate loading rate and input concentrations of calcium and acetate. Low nitrate-loading rates (i.e., ≤0.7 mol/m2-day) generally led to favorable outcomes (i.e., less accumulation of intermediates and more efficient carbonate precipitation). However, faster precipitation rates associated with low nitrate-loading rates led to smaller carbonate crystals and a less uniform precipitation pattern (i.e., precipitation focused near the nutrient source). Input concentrations of calcium and acetate also affected MIDP, but to a lesser extent than nitrate loading rate. The most important stimulated denitrifying bacteria, identified via 16S rDNA sequencing of suspended and dissolved DNA in the soil columns, were Bacillus species, Pseudomonas species, Brevundimonas species, and members of the Rhizobiaceae family. The results support that lower nitrate loading rates can be beneficial for MIDP although higher nitrate loading rates might be useful for some soil improvement applications.
AB - Three continuous-flow column experiments were conducted to investigate the effects of nitrate loading rate and input concentrations of acetate and calcium on the effectiveness of denitrification to promote microbially induced desaturation and precipitation (MIDP). MIDP differs from microbially induced carbonate precipitation (MICP) in that it relies upon desaturation by biogenic gas production, along with carbonate precipitation, to improve the behavior of saturated granular soil. Denitrification is a stepwise process that is susceptible to inhibition and accumulation of intermediates, like nitrite, due to unfavorable chemical conditions (e.g., low pH). Therefore, nitrate reduction, nitrite accumulation, calcite saturation, and formation of carbonate precipitates were monitored in the columns. Factors investigated in these experiments included the effects of nitrate loading rate and input concentrations of calcium and acetate. Low nitrate-loading rates (i.e., ≤0.7 mol/m2-day) generally led to favorable outcomes (i.e., less accumulation of intermediates and more efficient carbonate precipitation). However, faster precipitation rates associated with low nitrate-loading rates led to smaller carbonate crystals and a less uniform precipitation pattern (i.e., precipitation focused near the nutrient source). Input concentrations of calcium and acetate also affected MIDP, but to a lesser extent than nitrate loading rate. The most important stimulated denitrifying bacteria, identified via 16S rDNA sequencing of suspended and dissolved DNA in the soil columns, were Bacillus species, Pseudomonas species, Brevundimonas species, and members of the Rhizobiaceae family. The results support that lower nitrate loading rates can be beneficial for MIDP although higher nitrate loading rates might be useful for some soil improvement applications.
KW - Denitrification
KW - biomineralization
KW - microbially induced carbonate precipitation
KW - microbially induced desaturation and precipitation
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U2 - 10.1080/01490451.2019.1581858
DO - 10.1080/01490451.2019.1581858
M3 - Article
AN - SCOPUS:85063078030
SN - 0149-0451
VL - 36
SP - 543
EP - 558
JO - Geomicrobiology Journal
JF - Geomicrobiology Journal
IS - 6
ER -