title: Removal of trimethoprim, sulfamethoxazole, and triclosan by the green alga Nannochloris sp.
abstract: Trimethoprim (TMP), sulfamethoxazole (SMX), and triclosan (TCS) are widely used and continuously released into aquatic environments. Freshwater algae can be responsible for the uptake and transfer of the contaminants because they are a major food source for most aquatic organisms. This research applied incubation studies to evaluate the removal efficiency of TMP, SMX, and TCS by the green alga Nannochloris sp. The results showed that the hydrophilic antibiotics TMP and SMX remained in the algal culture at 100% and 68%, respectively, after 14days of incubation, and therefore were not significantly removed from the medium. However, the lipophilic antimicrobial TCS was significantly removed from the medium. Immediately after incubation began, 74% of TCS dissipated and 100% of TCS was removed after 7days of incubation. Additionally, over 42% of TCS was found associated with the algal cells throughout the incubation. The results demonstrate that the presence of Nannochloris sp. eliminated TCS in the aquatic system, but could not significantly remove the antibiotics TMP and SMX. The removal mechanisms of SMX and TCS were found to be different in the algal culture. Algae-promoted photolysis was the primary process for removing SMX and algae-mediated uptake played a major role in removing TCS.
authors.affiliation: Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV 89119, USA. Electronic address: Xuelian.Bai@dri.edu.
authors.forename: Xuelian
authors.initials: X
authors.lastname: Bai
authors.affiliation: Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV 89119, USA.
authors.forename: Kumud
authors.initials: K
authors.lastname: Acharya
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000528:radiation effects; D000890:Anti-Infective Agents / Q000378:metabolism* / Q000528:radiation effects; D001673:Biodegradation, Environmental; D000460:Chlorophyta / Q000254:growth & development / Q000378:metabolism*; D010782:Photolysis; D013420:Sulfamethoxazole / Q000528:radiation effects; D014260:Triclosan / Q000378:metabolism* / Q000528:radiation effects; D014295:Trimethoprim / Q000528:radiation effects; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D014874:Water Pollutants, Chemical; D014260:Triclosan; D014295:Trimethoprim; D013420:Sulfamethoxazole
keywords: Algae-mediated process; Pharmaceutical and personal care products (PPCPs); Sulfamethoxazole; Triclosan; Trimethoprim