Data analysis of treated wastewater impacts on coastal water parameters

¹ Democritus University of Thrace, Department of Physics, 65404 Kavala, Greece
² University of Macedonia, Department of Applied Informatics, 54636 Thessaloniki, Greece

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The discharge of treated or partially treated wastewater into water bodies is a common practice in many modern cities. However, this has often led to water quality degradation, ecological damage, and, in many cases, potential public health effects. This paper examines whether treated wastewater, discharged into a river, can affect coastal water quality at the river's mouth, located more than 80 kilometers away. For this purpose, measurements were taken over a period of five years, covering both the chemical characteristics of the wastewater and data on the water quality of the coastal ar-ea near the river mouth. After being properly processed, these data were combined based on their common date. The relationship between the variables was then analyzed to reveal potential correlations. Initially, an association was observed between the data from the two datasets, mainly through weak to moderate correlations between specific parameters. The nature of this ef-fect suggests limited direct linear relationships between many environmental indicators from the two sources. For this reason, further investigation was performed by applying Granger Causality test, multivariate Granger Causality and time-lagged correlations, especially for parameters with weak current linear correlations, to uncover more complex dependencies. Finally, the results were visualized and analyzed to draw useful conclusions.