The use of macrophyte-based systems for phosphorus removal: an overview of 25 years of research and operational results in Florida

Abstract

Phosphorus (P) removal from wastewaters and surface runoff using macrophyte-based systems (MBS) has been a topic of great interest in Florida for over 25 years. During this period, P removal by both treatment wetlands and floating aquatic macrophyte systems has been evaluated from both a research and operational standpoint. Several factors have contributed to the increased focus on the use of MBS for P removal. First, there exist no conventional technologies that can cost-effectively achieve the low outflow P concentrations required to protect the integrity of Florida's relatively pristine surface waters. Second, because MBSs typically provide some water storage, they can accommodate the wide ranges of flows typical for runoff sources such as agricultural drainage waters. Finally, many regions in Florida have sufficient area for deployment of the relatively land-intensive MBS technologies. The first P removal work in Florida was initiated in the mid-1970s, and involved pilot-scale research on domestic wastewater treatment by natural wetlands. Parallel studies were performed with managed (periodically harvested) floating plant systems (i.e., Eichhornia crassipes) for tertiary treatment. Since that time, the range of operational systems that have been deployed include emergent macrophyte-based and forested wetlands, managed floating plant systems, and submerged macrophyte-based systems. Waters treated by MBS include domestic effluents, agricultural runoff and eutrophic lake waters. Phosphorus removal targets for MBS in Florida have been as low as 10 microg/L. In this paper, we summarize research and operational results for MBS in Florida over the past 25 years.

Consequences of Excessive Overhead Irrigation on Runoff during Container Production of Sweet Viburnum

“…Similar results were observed for ortho-P where doubling the irrigation rate increased runoff ortho-P load 40% (3.0 vs 2.2 g/m 2 ) for FRT15 and 27% (6.1 vs 4.8 g/m 2 ) for FRT30 but decreased average flowweighted ortho-P concentration 42% (1.3 vs 2.3 mg/liter) for FRT15 and 44% (2.8 vs 4.9 mg/liter) for FRT30. Since total maximum daily load (TMDL) assessments target ortho-P levels of 0.1 mg/liter or less (11,16), results from this experiment indicate that runoff from container production beds under the conditions imposed during this experiment exceeded these concentrations and thus would be regarded as a potential source of undesirable P enrichment of water resources.…”

Seasonal dynamics of coper and zinc acumulation in shots of Phragmites australis (Cav.) Trin ex Steud., Typha latifolia L. and Typha angustifolia L.

“…Aquatic macrophytes are essential components of each aquatic freshwater ecosystem, with a number of important functional roles [Elis et al, 1994;Stojanović et al, 1994;Janković et al, 1988;DeBusk et al, 2001;Wetzel 2001;Stanković et al, 2009]. Aquatic plants can accumulate high amounts of heavy metals in some tissues, reaching up to 10-10 6 times higher concentrations than in the surrounding water or sediment.…”

Phosphorus Removal by Expanded Clay—Six Years of Pilot‐Scale Constructed Wetlands Experience

“…Constructed wetlands, which facilitate phosphorus removal via precipitation, adsorption, and biological uptake, offer a promising appropriate technology for advanced treatment, in new WWTPs or in the upgrading of plants that use only the primary and secondary treatments. Although they are area-intensive compared with conventional technologies, the application of these systems to wastewater treatment is an example of a clean technology (DeBusk et al, 2001;Verhoeven and Meuleman, 1999) and should be regarded as an acceptable, economically competitive alternative to traditional processes (White, 1995).…”