TY - JOUR
T1 - Performance evaluation of four field-scale agricultural drainage denitrification bioreactors in iowa
AU - Christianson, L.
AU - Bhandari, A.
AU - Helmers, M.
AU - Kult, K.
AU - Sutphin, T.
AU - Wolf, R.
PY - 2012
Y1 - 2012
N2 - Recently, interest in denitrification bioreactors to reduce the amount of nitrate in agricultural drainage has led to increased installations across the U.S. Midwest. Despite this recent attention, there are few peer-reviewed, fieldscale comparative performance studies investigating the effectiveness of these denitrification bioreactors. The object of this work was to analyze nitrate removal performance from four existing bioreactors in Iowa, paying particular attention to potential performance-affecting factors including retention time, influent nitrate concentration, temperature, flow rate, age, length-to-width ratio, and cross-sectional shape. Based on a minimum of two years of water quality data from each of the four bioreactors, annual removal rates ranged from 0.38 to 7.76 g N m-3 bioreactor volume d -1. Bioreactor and total (including bypass flow) nitrate-nitrogen load reductions ranged from 12% to 76% (mean 45%) and from 12% to 57% (mean 32%), respectively, removing from 0.5 to 15.5 kg N ha-1 drainage area. Multiple regression analyses showed that temperature and influent nitrate concentration were the most important factors affecting percent bioreactor nitrate load reduction and nitrate removal rate, respectively. This analysis also indicated that load reductions within the bioreactor were significantly impacted by retention time at three of the four reactors. More field-scale performance data from bioreactors of different designs and from multiple locations around the Midwest are necessary to further enhance understanding of nitrate removal in these systems and their potential to positively impact water quality.
AB - Recently, interest in denitrification bioreactors to reduce the amount of nitrate in agricultural drainage has led to increased installations across the U.S. Midwest. Despite this recent attention, there are few peer-reviewed, fieldscale comparative performance studies investigating the effectiveness of these denitrification bioreactors. The object of this work was to analyze nitrate removal performance from four existing bioreactors in Iowa, paying particular attention to potential performance-affecting factors including retention time, influent nitrate concentration, temperature, flow rate, age, length-to-width ratio, and cross-sectional shape. Based on a minimum of two years of water quality data from each of the four bioreactors, annual removal rates ranged from 0.38 to 7.76 g N m-3 bioreactor volume d -1. Bioreactor and total (including bypass flow) nitrate-nitrogen load reductions ranged from 12% to 76% (mean 45%) and from 12% to 57% (mean 32%), respectively, removing from 0.5 to 15.5 kg N ha-1 drainage area. Multiple regression analyses showed that temperature and influent nitrate concentration were the most important factors affecting percent bioreactor nitrate load reduction and nitrate removal rate, respectively. This analysis also indicated that load reductions within the bioreactor were significantly impacted by retention time at three of the four reactors. More field-scale performance data from bioreactors of different designs and from multiple locations around the Midwest are necessary to further enhance understanding of nitrate removal in these systems and their potential to positively impact water quality.
KW - Denitrification bioreactor
KW - Drainage
KW - Nitrate
KW - Water quality.
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M3 - Article
AN - SCOPUS:84872590631
SN - 2151-0032
VL - 55
SP - 2163
EP - 2174
JO - Transactions of the ASABE
JF - Transactions of the ASABE
IS - 6
ER -