wAbstract
@Agricultural runoff containing nitrogen fertilizer is a major
contributor to eutrophication in aquatic systems. One method of
decreasing amounts of nitrogen entering rivers or lakes is the
transport of runoff through vegetated drainage ditches. Vegetated
drainage ditches can enhance the mitigation of nutrients from
runoff; however, the efficiency of nitrogen removal can vary between
plant species. The efficiency of three aquatic macrophytes, cutgrass
(Leersia oryzoldes), cattail (Typha latifolia),
and burreed (Sparganium americanum), to mitigate dissolved
and total nitrogen from water was investigated. Replicate mesocosms
of each plant species were exposed to flowing water enriched with
ammonium and nitrate for 6 h, allowed to remain stagnant for 42
h, and then flushed with non-enriched water for an additional
6 h to simulate a second storm event. After termination of the
final simulated runoff, all vegetated treatments lowered total
nitrogen loads exiting mesocosms by greater than 50, significantly
more than unvegetated controls, which only decreased concentrations
by 26.9 (p
0.0023). L. oryzoides and T. latifolia
were more efficient at lowering dissolved nitrogen, decreasing
ammonium by 42}9 and 59}4 and nitrate by 67}6 and 64}7, respectively.
All treatments decreased ammonium and nitrate concentrations within
mesocosms by more than 86 after 1 week. However, T. latifolia
and L. oryzoides absorbed nitrogen more rapidly, lowering
concentrations by greater than 98 within 48 h. By determining
the nitrogen mitigation efficiency of different vegetative species,
plant communities in agricultural drainage ditches can be managed
to significantly increase their remediation potential.
Keywords: Ammonium; Nitrate; Phytoremediation; Mesocosmsx
1. Introduction
2. Materials and methods
@2.1. Experimental setup
@2.2. Simulated runoff
@2.3. Sample collection and analysis
3. Results
4. Discussion
Acknowledgments
References