Potential Uses of Stormwater Runoff Sediments Retained in a Constructed-Wetland/Storage-Tank

Objective: The goal of this work was to establish the quality conditions of the sediments retained in a constructed-wetland/storage-tank, which are to be used as productive material. Materials and methods: Sediments were collected every fortnight for five months in 2016, with sediment traps specially designed for the study case, to analyze particle size distribution, total organic carbon, and heavy metals concentrations. Sediment and hydrological data processing were performed using principal component analysis and multiple correspondence analysis. Results: The maximum measured concentrations were 110.80 mg/kg, 263.25 mg/kg, 798.85 mg/kg, and 3067 mg/kg for Cr, Cu, Pb, and Zn respectively; for total organic carbon was 20.6 mg. The sediment particles were considered thin (D50 < 150μm). Interesting relationships between rainfall and sediment characteristics were found. In shorter dry seasons, higher particle diameter, lower concentrations of heavy metals, and higher concentrations of total organic carbon were seen. Conclusions: Sediments are suitable for use in activities such as land remediation, vegetation of soils that are not for agricultural use, and as materials for ornamental and recreational areas. It is possible to use the sediments in embankments as tolerable soil for fillings of concrete structures and culverts in the core or foundation area.