CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Removal of organic contaminants in bioretention medium amended with activated carbon from sewage sludge

Karin Björklund (Institutionen för bygg- och miljöteknik, Vatten Miljö Teknik ; Institutionen för arkitektur och samhällsbyggnadsteknik, Vatten miljö teknik) ; Loretta Li
Environmental science and pollution research international (0944-1344). Vol. 24 (2017), 23, p. 19167–19180.
[Artikel, refereegranskad vetenskaplig]

Bioretention, also known as rain garden, allows stormwater to soak into the ground through a soil-based medium, leading to removal of particulate and dissolved pollutants and reduced peak flows. Although soil organic matter (SOM) is efficient at sorbing many pollutants, amending the bioretention medium with highly effective adsorbents has been proposed to optimize pollutant removal and extend bioretention lifetime. The aim of this research was to investigate whether soil amended with activated carbon produced from sewage sludge increases the efficiency to remove hydrophobic organic compounds frequently detected in stormwater, compared to non-amended soil. Three lab-scale columns (520 cm3) were packed with soil (bulk density 1.22 g/cm3); activated carbon (0.5% w/w) was added to two of the columns. During 28 days, synthetic stormwater—ultrapure water spiked with seven hydrophobic organic pollutants and dissolved organic matter in the form of humic acids—was passed through the column beds using upward flow (45 mm/h). Pollutant concentrations in effluent water (collected every 12 h) and polluted soils, as well as desorbed amounts of pollutants from soils were determined using GC-MS. Compared to SOM, the activated carbon exhibited a significantly higher adsorption capacity for tested pollutants. The amended soil was most efficient for removing moderately hydrophobic compounds (log Kow 4.0–4.4): as little as 0.5% (w/w), carbon addition may extend bioretention medium lifetime by approximately 10–20 years before saturation of these pollutants occurs. The column tests also indicated that released SOM sorb onto activated carbon, which may lead to early saturation of sorption sites on the carbon surface. The desorption test revealed that the pollutants are generally strongly sorbed to the soil particles, indicating low bioavailability and limited biodegradation.

Nyckelord: Bioretention; Column test; Dissolved organic matter; Hydrophobic organic pollutants; Rain garden; Sorption; Soil amendment; Stormwater management



Den här publikationen ingår i följande styrkeområden:

Läs mer om Chalmers styrkeområden  

Denna post skapades 2017-07-04. Senast ändrad 2017-09-14.
CPL Pubid: 250466

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för bygg- och miljöteknik, Vatten Miljö Teknik (2005-2017)
Institutionen för arkitektur och samhällsbyggnadsteknik, Vatten miljö teknik

Ämnesområden

Building Futures
Hållbar utveckling
Miljökemi
Vattenteknik

Chalmers infrastruktur