Sorption–desorption kinetics and toxic cell concentration in marine phytoplankton microalgae exposed to Linear Alkylbenzene Sulfonate
2011
Renaud, Florent | Oberhänsli, François | Teyssié, Jean-Louis | Miramand, Pierre | Temara, Ali | Warnau, Michel
Linear Alkylbenzene Sulfonates (LAS) are ubiquitous surfactants. Traces can be found in coastal environments. Sorption and toxicity of C₁₂-LAS congeners were studied in controlled conditions (2–3500μg C₁₂LAS/L) in five marine phytoplanktonic species, using standardized methods. IC₅₀ values ranged from 0.5 to 2mg LAS/L. Sorption of ¹⁴C₁₂-6 LAS isomer was measured at environmentally relevant trace levels (4μg/L) using liquid scintillation counting. Steady-state sorption on algae was reached within 5h in the order dinoflagellate>diatoms>green algae. The sorption data, fitted a L-type Freundlich isotherm, indicating saturation. Desorption was rapid but a low LAS fraction was still sorbed after 24h. Toxic cell concentration was 0.38±0.09mg/g for the studied species. LAS toxicity results from sorption on biological membranes leading to non-specific disturbance of algal growth. Results indicate that LAS concentrations in coastal environments do not represent a risk for these organisms.
显示更多 [+] 显示较少 [-]