Improved urban stormwater treatment and pollutant removal pathways in amended wet detention ponds

Abstract

Dissolved and colloidal bound pollutants are generally poorly removed from stormwater in wet detention ponds. These fractions are, however, the most bio-available, and therefore three wet detention ponds were amended with planted sand filters, sorption filters and addition of precipitation chemicals to enhance the removal of dissolved pollutants and pollutants associated with fine particles and colloids. The three systems treated runoff from industrial, residential and combined (residential and highway) catchments and had permanent volumes of 1,990, 6,900 and 2,680 m(3), respectively. The treatment performance of the ponds for elimination of total suspended solids (TSS), total nitrogen (Tot-N), total phosphorous (Tot-P), PO(4)-P, Pb, Zn, Cd, Ni, Cr, Cu, Hg were within the range typically reported for wet detention ponds, but the concentrations of most of the pollutants were efficiently reduced by the planted sand filters at the outlets. The sorption filters contributed to further decrease the concentration of PO(4)-P from 0.04 ± 0.05 to 0.01 ± 0.01 mg L(-1) and were also efficient in removing heavy metals. Dosing of iron sulphate to enrich the bottom sediment with iron and dosing of aluminium salts to the inlet water resulted in less growth of phytoplankton, but treatment performance was not significantly affected. Heavy metals (Pb, Zn, Cd, Ni, Cr and Cu) accumulated in the sediment of the ponds. The concentrations of Zn, Ni, Cu and Pb in the roots of the wetland plants were generally correlated to the concentrations in the sediments. Among 13 plant species investigated, Rumex hydrolapathum accumulated the highest concentrations of heavy metals in the roots (Concentration Factor (CF) of 4.5 and 5.9 for Zn and Ni, respectively) and Iris pseudacorus the lowest (CF < 1). The translocation of heavy metals from roots to the aboveground tissues of plants was low. Therefore the potential transfer of heavy metals from the metal-enriched sediment to the surrounding ecosystem via plant uptake and translocation is negligible.

Ecological Risk Assessment of Trace Elements Accumulated in Stormwater Ponds within Industrial Areas

“…The concentrations of commonly-monitored trace elements (i.e. Cd, Cr, Cu, Ni, Pb, Zn) were detected within the same order of magnitude as those observed in several previous international and national studies (Jang et al 2010;Blecken et al 2012;Istenič et al 2012;Egemose et al 2015;Frost et al 2015;Sharley et al 2017;Crane 2019;Sun et al 2019), but lower maximum concentration values were obtained here compared to those found in ponds within industrial areas (Sharley et al 2017). Blecken et al (2012) also detected six-fold higher Cr concentrations in sediment close to stormwater outlets, while Jang et al (2010) observed four-fold higher maximum values in road residues.…”

Sorption and Degradation Potential of Pharmaceuticals in Sediments from a Stormwater Retention Pond

“…Degradation is more associated with the activity of microorganisms present in the sediment-water system [18,19], where redox potential and oxygen condition are main factors [20][21][22][23]. Studies have already shown that stormwater retention ponds can reduce pollutants including polycyclic aromatic hydrocarbons (PAHs), heavy metals and biocides by processes like adsorption, sedimentation and degradation [24][25][26]. However, less is known about the fate of pharmaceuticals in such ponds, especially the removal mechanisms and the main factors that govern removal rates.…”

Active biomonitoring withCorbiculafor USEPA priority pollutant and metal sources in the Anacostia River (DC, Maryland, USA)

“…A targeted, less costly and less disruptive plan to control the downstream transfer of chlordane from sources is suggested by this research and others where up to 94% of TPAH in Lower Paint Branch was retained by an experimental urban stormwater bioretention facility (DiBlasi et al ). Holding ponds and cisterns have been examined as intercepts for TSS contaminants (Somes et al ; Istenic et al ). Immobilization of pond‐trapped contaminants by in situ toxics management using C has been reported (Ghosh et al ).…”