A Preliminary Analysis of the Correlation of Heavy Metals with TN, TP and TSS in Constructed Wetland

Abstract

Constructed wetland (CW) has been receiving increased popularity in urban cities to treat stormwater runoffs following the best practice management guidelines which only focuses on TN, TP and TSS. However, the presence of heavy metals is also detected in CWs. This paper presents the water quality monitoring results of a CW in Melbourne, Australia. A statistical analysis has been undertaken to determine the correlation of heavy metals with TN, TP and TSS. The analysis revealed that the treatment performance did not comply with the best practice management guidelines and the wetland is experiencing significant metal pollution. The results showed that TN and TP concentrations are negatively correlated and TSS are strongly correlated with the concentration of metal pollutants including Al, Cu and Fe. Meanwhile, significant correlations are discovered between metals such as Zn and Cu, Al and Cr than between the common pollutants. As this is a preliminary analysis, further investigations are needed to validate the relationships. It is envisioned that the outcome of this research will assist CWs owners and managers to assess the effectiveness of CWs in reducing the levels of not only the common three pollutants but also heavy metals.