Description
Landscape Setting and Practice Design:
Dundas:
Field is gently undulating with 0-1 percent slopes. Soil type is predominantly a Dundas silt loam that is pattern tiled at a 40 ft. spacing and 4.0 ft. depth. The bioreactor is located within a buffer strip, separating the crop land and a drainage ditch. The site very rarely experience flooding from the ditch. Bioreactor dimensions measure 90 ft. length by 3.0 ft. width by 6.0 ft. depth (4.0 ft. woodchips and 2.0 ft. topsoil). The bioreactor receives drainage water from two separate fields, one with controlled drainage and one with uncontrolled (free) drainage. The controlled drainage system contributes 6.6 acres, while the uncontrolled system contributes 15.6 acres of tile flow. The controlled drainage system utilizes an AgriDrain structure to manipulate flow within the system.
Claremont:
Field is gently sloping with 1-2 percent grade. Soil type is almost exclusively a Maxfield silty clay loam which is pattern tiled at an 80 ft. spacing and 4 ft. depth. The bioreactor is located across the road from the field it drains. Flooding within the field is rare, however, the bioreactor and surrounding area does experience flooding conditions, as it is located 0.5 miles upstream from a drainage ditch, which is shallow and undersized. Bioreactor dimensions measure 240 ft. length by 3.5 – 4.0 ft. width by 6.0 ft. depth (4.0 ft. woodchips and 2.0 ft. topsoil). The bioreactor receives drainage from a single field which contributes 26 acres of tile flow. The bioreactor uses an Agridrain controlled drainage structure to manipulate flow within the system.
Table 6. Concentration and flow-weighted load of Total Phosphorus. Column description is similar to
that of nitrate table above. No amount phosphorus was added to the flowing water.
Area-normalized loads at inlet and outlet give 28.5 g/ha and 5.97 g/ha, respectively.
Overall total phosphorus reduction is 79%.
Table 7. Concentration and flow-weighted load of Acetochlor. Target and actual range of concentration achieved are given with cycle cumulative mass at both ends of the bioreactor. With the cumulative values, area-normalized loads are 0.54 g/ha and 0.16 g/ha at inlet and outlet. Overall Acetochlor load reduction is 70%.
Table 8. Linear equations per cycle of Acetochlor experiment
based on Bohart-Adams model (Equation #3 in text). The units proposed by Keerthinarayana and Bandyopadhyay (1997) were used in this linearization (mg, cm3, hr).
Daily linear velocities are shown in Table 4. K is a rate constant and No is adsorptive capacity. Wood adsorption is derived from difference between inlet and outlet concentration reported to woodchip mass per unit volume.
Table 10. Concentration and flow-weighted load of Atrazine. With the cumulative values, area-normalized loads are 0.54 g/ha and 0.16 g/ha at inlet and outlet.
Overall Atrazine load reduction is 53%
Dundas:
Field is gently undulating with 0-1 percent slopes. Soil type is predominantly a Dundas silt loam that is pattern tiled at a 40 ft. spacing and 4.0 ft. depth. The bioreactor is located within a buffer strip, separating the crop land and a drainage ditch. The site very rarely experience flooding from the ditch. Bioreactor dimensions measure 90 ft. length by 3.0 ft. width by 6.0 ft. depth (4.0 ft. woodchips and 2.0 ft. topsoil). The bioreactor receives drainage water from two separate fields, one with controlled drainage and one with uncontrolled (free) drainage. The controlled drainage system contributes 6.6 acres, while the uncontrolled system contributes 15.6 acres of tile flow. The controlled drainage system utilizes an AgriDrain structure to manipulate flow within the system.
Claremont:
Field is gently sloping with 1-2 percent grade. Soil type is almost exclusively a Maxfield silty clay loam which is pattern tiled at an 80 ft. spacing and 4 ft. depth. The bioreactor is located across the road from the field it drains. Flooding within the field is rare, however, the bioreactor and surrounding area does experience flooding conditions, as it is located 0.5 miles upstream from a drainage ditch, which is shallow and undersized. Bioreactor dimensions measure 240 ft. length by 3.5 – 4.0 ft. width by 6.0 ft. depth (4.0 ft. woodchips and 2.0 ft. topsoil). The bioreactor receives drainage from a single field which contributes 26 acres of tile flow. The bioreactor uses an Agridrain controlled drainage structure to manipulate flow within the system.
Table 6. Concentration and flow-weighted load of Total Phosphorus. Column description is similar to
that of nitrate table above. No amount phosphorus was added to the flowing water.
Area-normalized loads at inlet and outlet give 28.5 g/ha and 5.97 g/ha, respectively.
Overall total phosphorus reduction is 79%.
Table 7. Concentration and flow-weighted load of Acetochlor. Target and actual range of concentration achieved are given with cycle cumulative mass at both ends of the bioreactor. With the cumulative values, area-normalized loads are 0.54 g/ha and 0.16 g/ha at inlet and outlet. Overall Acetochlor load reduction is 70%.
Table 8. Linear equations per cycle of Acetochlor experiment
based on Bohart-Adams model (Equation #3 in text). The units proposed by Keerthinarayana and Bandyopadhyay (1997) were used in this linearization (mg, cm3, hr).
Daily linear velocities are shown in Table 4. K is a rate constant and No is adsorptive capacity. Wood adsorption is derived from difference between inlet and outlet concentration reported to woodchip mass per unit volume.
Table 10. Concentration and flow-weighted load of Atrazine. With the cumulative values, area-normalized loads are 0.54 g/ha and 0.16 g/ha at inlet and outlet.
Overall Atrazine load reduction is 53%
Date Issued
2016-10-10
Number of Pages
12
Decade
Associated Organization
Publisher
University of Minnesota Soil Water Climate Dept.
Minnesota Department of Agriculture
Format
Rights Holder
University of Minnesota
Rights Management
Public Domain