Wood mulch coated with iron-based water treatment residuals for the abatement of metals and phosphorus in simulated stormwater runoff

Abstract Laboratory-scale batch and flow-through studies evaluated the performance of iron-based water treatment residuals (Fe-WTR) coated wood mulch for removing two types of urban stormwater runoff pollutants i.e., toxic heavy metals (Cu, Zn, and Pb) and the nutrient, phosphorus (P). Fe-WTR is an industrial waste byproduct generated from the treatment of drinking water, primarily comprising amorphous iron (hydr)oxides. The Fe-WTR particles had a large surface area and were non-hazardous, as indicated by toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) tests. Batch studies of WTR-coated mulch loaded with simulated urban stormwater fixed pollutant concentrations showed fast (