Capacity of a horizontal subsurface flow constructed wetland system for the removal of emerging pollutants: an injection experiment.
A continuous injection experiment was implemented in a pilot-scale horizontal subsurface flow constructed wetland system to evaluate the behavior of four pharmaceuticals and personal care products (i.e. ibuprofen, naproxen, diclofenac and tonalide) and a phenolic estrogenic compound (i.e. bisphenol A). The treatment system consisted of an anaerobic reactor as a primary treatment, followed by two 0.65 m² wetlands (B1 and B2) working in parallel and connected to a 1.65 m² wetland (B3) operating in series. Overall removal efficiencies for the selected compounds ranged from 97% to 99%. The response curves of the injected pollutants show that the behavior of these compounds strongly depends on their sorption and biodegradation characteristics. While about 50% of ibuprofen was removed in B1 and B2, 99% was achieved at B3, where the dissolved oxygen concentration was significantly higher (B1-B2=0.5 mg L⁻¹ and B3=5.4 mg L⁻¹). Naproxen and diclofenac were efficiently removed (93%) in B1 and B2, revealing anaerobic degradation as a probable removal mechanism. Moreover, tonalide and bisphenol A were readily removed in the small wetlands (94% and 83%, respectively), where the removal of total suspended solids was 93%. Therefore, given their high hydrophobicity, sorption onto the particulate matter stands for the major removal mechanism. However, the tentative identification of carboxy-bisphenol A as an intermediate degradation product in B3 suggested biodegradation as a relevant bisphenol A removal pathway under aerobic prevailing conditions.
Avila
Cristina
C
Environmental Engineering Division, Department of Hydraulic, Maritime and Environmental Engineering, Technical University of Catalonia, C/Jordi Girona 1-3, Barcelona, Spain. cristina.avila@upc.edu
Pedescoll
Anna
A
Matamoros
Víctor
V
Bayona
Josep María
JM
García
Joan
J
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis / Q000737:chemistry*; D004008:Diclofenac / Q000032:analysis / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D007052:Ibuprofen / Q000032:analysis / Q000737:chemistry; D009288:Naproxen / Q000032:analysis / Q000737:chemistry; D010476:Perfume / Q000032:analysis / Q000737:chemistry*; D013764:Tetrahydronaphthalenes / Q000032:analysis / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D053833:Wetlands
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010476:Perfume; D013764:Tetrahydronaphthalenes; D014874:Water Pollutants, Chemical; D004008:Diclofenac; C033116:acetyl methyl tetramethyl tetralin; D009288:Naproxen; D007052:Ibuprofen