Novel Fe and Mn oxide catchbasin filter media to improve the quality of runoff water and its application to extract isotopic tracers

Abstract:

Urbanization has not only increased the quantity of stormwater runoff entering storm drains but also deteriorate its quality. Catch basin filters or inserts, which are often viewed as only a sediment trap, can be employed to remove the potential contaminants from the runoff water before entering the sewers. Catch basin inserts are boxes of various filter media that are generally placed under individual sewer grates. They have the sediment trap on the top layers followed by different filter media layers to remove the pollutants from the runoff water. Although the catch basin has the potential to remove the pollutants from the runoff water, they haven’t received significant attention to date. In this study, Fe and KMnO₄ coated polypropylene filters were used as the sorbent materials to remove phosphate and copper ions from water by the adsorption process. Batch experiments were performed using synthetic pollutant solution to understand reaction kinetics. The pH of the solution was measured along with the contaminants concentration at different time intervals. Thermodynamic parameters were determined by the performing experiments at different temperature. The concentration of total dissolved phosphates in runoff water samples collected from Detroit, MI area was also evaluated. KMnO₄ coated polypropylene fabric material has shown better performance when compared to the iron coated fabrics. Increase in the pH of the synthetic phosphate solution was observed with time. The main purpose of this research is to develop a sorbent that could be used to extract and concentrate phosphate from freshwater systems to provide enough mass of phosphorus to analyze the sample for small concentrations of cosmogenic radioactive isotopic tracers (P-32 and P-33). These isotopes will help tracking the sources and sinks of phosphate in freshwater systems and their applications will be discussed.