This dataset includes four drainage discharge files, four water chemistry files, three 5-minute concentration and loads files, and two ancillary files that support the peer-reviewed journal article, “Can woodchip bioreactors be used at a catchment scale? Nitrate performance and sediment considerations.” Measurements were taken from the outlet of a 249-ha watershed in southern Minnesota from September 2016 through July 2017. The watershed outlet became the inlet to a system of three woodchip bioreactor beds. The purpose of the study was to determine nitrate removal performance of the bioreactor system and the percentage of watershed flow that could be treated by it.
The discharge data were collected at a 5-minute time interval. The file “Flow_CD62in_adj.csv” contains the discharge from the entire watershed. The data column “CD62in_Adj” contains the discharge data in units of cubic feet per second (cfs). Flow was measured with an area velocity sensor in a smooth-walled 24-inch diameter PVC pipe. Discharge data from the three bioreactor beds are found in the files named “Flow2_BR1.csv”, “Flow2a_BR2_csv”, and “Flow2_BR3.csv”. The bioreactor discharge data are also provided in units of cfs. Bioreactor discharge was calculated using a v-notch weir equation; water table depth behind the weirs was measured with pressure transducers connected to dataloggers.
Like the discharge data files, water chemistry files are provided for the watershed outlet, “Concs_CD62in_v2.csv”, and the three bioreactor beds: “Concs_BR1_v2.csv”, “Concs_BR2_v2a.csv”, and “Concs_BR3_v2a.csv”. During the experiment, water samples were collected manually or by automated samplers with a flow-weighted sampling scheme. The date-times of the manual sampling are noted as are those of the first and last subsamples for automated sampling. Water parameters in the dataset include: pH; and nitrate-N, ammonium-N, total-N, dissolved reactive P, total-P, dissolved C, dissolved inorganic C, dissolved organic C, and sulfate-S concentrations.
The 5-minute concentration and load files contain the concentrations of water parameters noted above and the masses of each parameter for the three bioreactor beds: “BR1_5-min_concs loads.csv”, “BR2_5-min_concs loads.csv”, and “BR3_5-min_concs loads.csv”. Concentrations were assigned to each 5-minute discharge interval using the midpoint in discharge volume between water samples as the dividing point.
These ancillary files are included:
“HRTs_daily.xlsx” – the hydraulic residence times at a daily timestep for each of the three bioreactor beds, in units of hours.
“WaterTemp_2016-17.csv” – water temperature from the watershed outlet/bioreactor system inlet and from the three bioreactor outlets, in units of (°C).
More details about the experiment and measurement and analysis methods can be found in the accompanying journal article (https://doi.org/10.13031/ja.15496) and supplementary materials mentioned in the article (https://doi.org/10.13031/21964643).
