View Full Table | Close Full ViewTable 1.

Chemical and physical properties of undredged and dredged ditch sediments.

 
Sediments NO3–N NH4–N CEC† pH OM Sand Silt Clay
mg kg−1 meq kg−1 g kg−1
Dredged 1.0 11.0 32 4.9 2.2 680 170 150
Undredged 13.2 25.3 96 4.2 85 190 340 410
CEC, cation exchange capacity; OM, organic matter.



View Full Table | Close Full ViewTable 2.

Nitrate and ammonium concentrations in ditch sediments at different phases during the flume experiment.

 
Dredged Undredged
Phases NO3–N NH4–N NO3–N NH4–N
mg kg−1 mg kg−1
Before equilibration 0.9 (0.0)† 10.9 (1.02) 13.1 (6.78) 25.3 (1.4)
End equilibration 0.8 (0.14) 13.5 (1.73) 26.3 (3.90) 4.1 (0.3)
End uptake 0.9 (0.0) 13.6 (0.48) 10.1 (1.34) 24.7 (2.2)
End release 1.3 (0.17) 7.2 (1.09) 12.3 (2.79) 16.1 (0.6)
Standard deviations are in parentheses.



View Full Table | Close Full ViewTable 3.

Nitrate and ammonium processing length (Sw), mass transfer coefficient (Vf), and nutrient uptake (U) during the initial and final 24 h of uptake flume experiment.

 
Dredged Undredged
Phases Sw Vf U Sw Vf U
m cm h−1 mg m2 h−1 m cm h−1 mg m2 h−1
0–24 h
 NO3–N −33,333 −0.040 −2.160 −250,000 −0.006 −0.29
 NH4–N 166,667 0.010 1.120 20,000 0.007 9.400
24−48 h
 NO3–N 166,667 0.010 0.430 200,000 0.007 0.360
 NH4–N −2,500,000 −0.0003 −0.070 100,000 0.010 1.870