Enhanced Removal of Nutrients, Heavy Metals, and PAH from Synthetic Stormwater by Incorporating Different Adsorbents into a Filter Media

Abstract

Stormwater harvesting and reuse is an attractive option to lower the demand placed on other sources of water supply. However, it contains a wide range of pollutants that need to be removed before it can be reused or even discharged to the waterways and receiving waters. An experimental protocol to estimate the efficiency of a soilbased-filter medium for the treatment of stormwater pollutants from 1-3 years rainfall experienced in the field was developed using a laboratory column-set-up over short-term duration. The filter removed substantial amounts of PO 4 -P and NH 4 -N for up to 8 h at a flow velocity of 100 mm/h which is a one-year time-equivalent of rainfall at a locality in Sydney, Australia. An addition of 10% zeolite to the soil-based filter extended the column saturation period to 24 h. The breakthrough data for PO 4 -P and NH 4 -N were satisfactorily described by the Thomas model. The majority of the nine heavy metals tested were removed by more than 50% for up to 4 h in the soil-based filter. This level of removal increased to 16 h when 10% zeolite was added to the filter. The column with the soil-based filter + 10% zeolite had higher affinity for Pb, Cu, Zn and As than Ni, with Pb having the highest percentage removal. Soil-based filter + 10% zeolite removed considerable amounts of 3 polycyclic aromatic hydrocarbons (PAHs) (30-50%), while Soil-based filter + 10% zeolite + 0.3% granular activated carbon removed 65 to > 99% of the PAHs at 24 h operation.

Evaluation of sorbents and matrix effects for treating heavy metals and per- and polyfluoroalkyl substances as co-contaminants in stormwater

“…The complex synthetic stormwater, which includes additional salts and is similar to synthetic stormwaters that are commonly used, 36–38 demonstrated no significant differences in sorbent performance at retaining either heavy metals or PFAS. In fact, the only stormwater component that resulted in significant decreases in heavy metals or PFAS removal was organic matter (Fig.…”

Adsorption of Heavy Metals and Biocides from Building Runoff onto Granular Activated Carbon—The Influence of Different Fractions of Dissolved Organic Matter

“…The solid-to-liquid ratio (GAC/Milli-Q water) of this reaction system was maintained at 2 mg/mL. The concentrations of DOM in the adsorption batch tests were 2,4,6,8,10,20,30,40,50,100,200,400, and 600 mgC/L (DOM fraction 3-10 kDa did not include the maximum concentration). For samples with a DOM concentration of less than 40 mgC/L, the test volume was 100 mL (200 mg GAC added); for samples with a DOM concentration of 50 and 100 mgC/L, it was 50 mL (100 mg GAC added); the remaining tests were performed using a volume of 15 mL (30 mg GAC added).…”

“…In this context, a granular activated carbon (GAC)-based decentralized on-site runoff treatment is a promising option in the mitigation of building runoff pollution because such a system has the advantages of high efficiency, cost-effective, and flexibility in construction. As a porous material with a large surface ratio, GAC has been previously applied in stormwater pollution elimination [20][21][22][23] and water quality assurance [24][25][26][27].…”