Performance Evaluation and Seasonal Variations of the Physico-Chemical Parameters of Water Quality in a Wetland In Nashville, Tennessee

Mark C Okafor, Tennessee State University


Pollutant removal from surface waters in wetlands is crucial to mitigate the contamination of downstream ecosystems and to protect the health of aquatic organisms. Urban wetlands receiving surface runoff contain pollutants from natural and anthropogenic sources. A wetland adjacent to the Tennessee state university’s greenhouse research facility was studied for a year. In this study, we evaluated the pollutant removal efficiency of the wetland. NO3-N, TP, K, As, Zn, Mg, Ca, Na, Si, Ba, B, and Sr levels were measured and removal efficiencies calculated. NO3-N and Na had removal efficiencies of 28.4% and 14.07% respectively, and their means were statistically significant. Mean difference in TP concentration was not significant. The high Ca concentration indicates the wetland is alkaline and the concentrations of most metals were below detection limits. Investigating the physical and chemical parameter of water quality reveals the variation of these pollutants in wetlands. The second objective of this study seeks to understand the influence of spatial and seasonal changes on a wetland’s bio-geochemistry and the behavior of these parameters. The parameters of study include water temperature, turbidity, specific conductivity, dissolved oxygen (DO), hydrogen ion concentration (pH), nutrients (NO3-N, TP), ions (B, Na, Mg, Ca, K, Si) and metals (As, Sr, Ba, Zn, Pb). A two-way analysis of variance (ANOVA) revealed that the effect of seasonal changes is significant (p <.05) for all parameters. Our results demonstrated a range of variabilities from warm and cold season to growing seasons. A correlation matrix showed both strong and moderate positive to negative correlations among the parameters. The correlation coefficients significant at p = .05 revealed that most parameters were correlated with temperature and turbidity did not increase with rainfall. pH, Mg and Ca levels indicate that there is a groundwater interchange. Other pollutants with high levels are Na, K, and P suggesting influences from anthropogenic activities. The removal efficiency of this natural urban wetland is less to moderately efficient.

Subject Area

Environmental science

Recommended Citation

Mark C Okafor, "Performance Evaluation and Seasonal Variations of the Physico-Chemical Parameters of Water Quality in a Wetland In Nashville, Tennessee" (2017). ETD Collection for Tennessee State University. Paper AAI10615367.