POSTER: Evaluation and optimization of pilot-scale floating aquatic treatment wetlands for phytoremediation pre-treatment of municipal landfill leachate employing saline-tolerant plants native to South Florida
Research Mentor: Dr. Ashley Danley-Thomson
Additional Authors: 
Abstract:
This research was the continuation (Phase III) of the evaluation and optimization of pilot-scale floating aquatic treatment wetlands for phytoremediation pre-treatment of municipal landfill leachate employing saline-tolerant plants native to South Florida. Phase III was structured off Phase I and II of the preceding research, twelve monocultures each placed in a batch reactor and four polycultures placed in floating wetlands, respectively, with modifications made to combine both phases and implement other additional methods. Phase III consisted of a polyculture of Florida native plants planted in a floating wetland and placed within leachate storage ponds located at the Lee and Hendry Regional Solid Waste Disposal Facility. The research conducted had two primary objectives. To provide design criteria for floating treatment wetlands so landfill managers can reduce leachate management costs by pre-treating leachate with floating aquatic treatment wetlands and to remove toxins such as heavy metals within the leachate via phytoremediation prior to the leachate being discharged for treatment. Pre-treatment of leachate (liquid that has percolated through the garbage within a landfill) by means of floating wetlands and phytoremediation is viewed as a viable option since it is a low-cost, low-maintenance option, with the potential of lowering costs for landfill operators. If leachate is sent to a wastewater treatment plant (WWTP), managers often pay a discharge fee based on the leachate volume discharged and concentrations of certain parameters. Any pre-treatment that can occur prior to discharge to a WWTP will lower discharge costs. Prior to the research site set up, occurring on July 26th, 2021, at the Lee and Hendry Regional Solid Waste Disposal Facility, research was conducted on leachate holding containers, floating wetlands, soil, biochar, and microorganisms to utilize for this project. Four 2,500-gallon leachate holding containers were placed in a landfill cell and filled approximately halfway with leachate. E ach container had a floating wetland filled with soil placed within. Container 1 was the control and only contained the wetland and soil. Container 2 had the addition of plants (red/black/white mangroves and mangrove spider lilies). Container 3 had the addition of biochar. Finally, Container 4 had the addition of microorganisms including salt and metal tolerant, and epiphyte. Since the initial site set up, sampling has occurred biweekly with the samples acquired frozen until analysis in the laboratory. As laboratory analysis of samples begin, ammonia, phosphate, chemical oxygen demand (COD), nitrite, nitrate, and heavy metals will be analyzed.