Evaluating macrophyte selection and germination protocols to enhance nutrient sequestration in engineered wetland models

Research examining contaminant sequestration using engineered wetlands has been conducted for many years but the implementation of sustainable, biodiverse strategies is still in its infancy. A major gap in knowledge still exists regarding the kinds of macrophytes to be selected, especially the inclusion of non-invasive native flora. There is a lack of information about macrophyte selection criteria and germination protocols. Thus, this study attempted to redress this dearth in knowledge. The first part of this thesis critically assessed a list of macrophytes provided by Environment Canada (1996) and created “selection criteria” for choosing specific macrophytes. Germination protocols were then compiled to determine and outline optimized germination protocols for these aquatic macrophytes. In the second part of this study, two different constructed wetlands models were designed for laboratory purposes (a “floating” constructed wetland model and a “stationary” constructed wetland model). Water samples were assed for biological impact and phosphorus concentration.

Evaluating macrophyte selection and germination protocols to enhance nutrient sequestration in engineered wetland models

Research examining contaminant sequestration using engineered wetlands has been conducted for many years but the implementation of sustainable, biodiverse strategies is still in its infancy. A major gap in knowledge still exists regarding the kinds of macrophytes to be selected, especially the inclusion of non-invasive native flora. There is a lack of information about macrophyte selection criteria and germination protocols. Thus, this study attempted to redress this dearth in knowledge. The first part of this thesis critically assessed a list of macrophytes provided by Environment Canada (1996) and created “selection criteria” for choosing specific macrophytes. Germination protocols were then compiled to determine and outline optimized germination protocols for these aquatic macrophytes. In the second part of this study, two different constructed wetlands models were designed for laboratory purposes (a “floating” constructed wetland model and a “stationary” constructed wetland model). Water samples were assed for biological impact and phosphorus concentration.

Assessment of Non-Anthropogenic Addition of Uric Acid to a Water Treatment Wetlands

Artificial water-treatment wetlands can reduce nitrogen and phosphorous nutrient concentrations in wastewater effluent to improve water quality and decrease eutrophication in natural waters. The Orlando Easterly Wetlands (OEW) is an engineered wetland that polishes 57 million liters of wastewater per day, lowering the total nitrogen and phosphorous concentrations through biological, physical, and chemical processes. In addition to purifying the water, the wetlands provide habitat for avian, mammalian, reptilian and macroinvertebrate species. Previous research has shown that avian species affect the eutrophication of agricultural reservoirs near their roost. The research herein quantifies uric acid in avian and reptilian excretory product and tracks its concentration profile throughout the OEW over a seven-month period. This measure of the non-anthropogenic contribution to nitrogen within the park includes winter months when large numbers of migratory birds occupy the wetland. The enzymatic decomposition of uric acid and the subsequent fluorimetric analysis were used to quantify uric acid throughout the flow train of the OEW. High concentrations of 2–4 mg/L uric acid were found in the influent, but drastically declined to concentrations below 0.2 mg/L in the effluent.

Laboratory tests of Estonian landfill leachate

During the last decade, many laboratory, pilot and full-scale experiments have beenconducted to investigate the optimal low-tech purification methods for the treatment ofnumerous types of wastewaters. Constructed wetland is a low-tech treatment system, whichusually contains multiple treatment possibilities. Frequently, some kind of soil treatmentsystem is included as one treatment stage. Engineered wetland systems for purification ofwastewater and leachate are not yet widely spread in Estonia. The possibility to use peat asfilter media for treatment of leachate from Aardlapalu landfill (Tartu County, Estonia) hasbeen studied. The leachate was transported into the laboratory, aerated and percolated throughtwo different types of peat filters. The concentration of nitrogen compounds, COD and BODwas measured in the leachate before and after treatment. Hydrological consequences andchemical changes in the peat were investigated.