**Author details**

tration rise associated with stop-log box 4B. Nitrate-N concentrations from 2 December to 7 December 2015 ranged from 35.1 mg NO3-N/L to 20.6 mg NO3-N/L for the inlet concentrations and from 25.3 mg NO3-N/L to 17.2 mg NO3-N/L for the outlet concentrations. From 8 December to 13 December 2015, the inlet and outlet nitrate-N concentrations became increasingly smaller, and the outlet nitrate-N concentrations continued to be smaller than those of the corresponding

**Figure 6.** Water nitrate concentrations from the inlet (influx) and outlet (effluent) from the denitrification bioreactor.

Ammonium-N concentrations were substantially smaller than the corresponding nitrate-N concentrations. Ammonium-N concentration differences between the inlet and outlet waters suggest that the denitrification bioreactor sequestered ammonium-N or nitrification processes oxidized ammonium to nitrate (**Figure 7**). Denitrification bioreactor's mean phosphorus concentrations were smaller for the effluent (0.29 mg PO4-P/L) than the inlet concentrations (0.38 mg PO4-P/L); however, the concentration differences were not significant. Denitrification bioreactor's mean sulfate concentrations were greater for the effluent (1.1 mg SO4-S/L) than the inlet concentrations (1.0 mg SO4-S/L); however, the sulfate-S concentration differences were

Denitrification bioreactors in these field trials reduced effluent nitrate-N concentrations via denitrification pathways. Approximately 50% or greater nitrate-N reductions were observed when the flow volumes per unit time were sufficiently small for equilibrium attainment.

inlet concentrations.

16 Soil Contamination - Current Consequences and Further Solutions

not significant.

Michael Aide\* , Indi Braden and Sven Svenson

\*Address all correspondence to: mtaide@semo.edu

Department of Agriculture, Southeast Missouri State University, Cape Girardeau, Missouri, USA
