『Abstract
In the greenhouse and container nursery production industry there
is potential for runoff of nitrogen (N) and phosphorus (P), which
may contaminate surface and groundwater. Since the 1950s constructed
wetlands (CWs), as a simple, low-technology method, have been
shown to effectively treat agricultural, industrial, and municipal
wastewater. We investigated the N and P attenuating potential
of three floating hydrophytes planted in a laboratory-scale subsurface
flow (SSF) CW system. Over an 8-week period plants were supplied
with N and P (0.39 to 36.81 mg・L-1 N and 0.07 to 6.77
mg・L-1 P) that spanned the rates detected in nursery
runoff between the discharge and inflow locations of a commercial
nursery currently employing CWs. Whole plant dry weight was positively
correlated with N and P supplied. Highest N recovery rates were
exhibited by water hyacinth (Eichhornia crassipes [Mart.]
Solms) and water lettuce (Pistia stratiotes L.). P recovery
rates were similar for water hyacinth, water lettuce, and dwarf
redstemmed parrotfeather (Myriophyllum aquaticum [Vell.]
Verdc.). These floating hydrophytes can be cultivated in a SSF
CW to remediate runoff losses of N and P. The possibility exists
for integrating them into a polycultural remediation system that
includes emergent aquatic macrophytes for processing and polishing
nursery/greenhouse wastewater.
Keywords: Nursery runoff; Nutrient contaminants; Parrotfeather;
Phytoremediation; Water hyacinth; Water lettuce; Water quality』
1. Introduction
2. Methods
2.1. Plant characterization and culture
2.2. Nitrogen and phosphorus treatment solutions
2.3. Plane and water analysis
2.4. Statistical analysis
3. Results and discussion
3.1. Biomass accumulation
3.2. N and P recovery
3.3. Nitrogen and phosphorus tissue concentration
3.4. Nitrogen and phosphorus tissue content
4. Conclusions
Acknowledgments
References