Evaluation of a battery of marine species-based bioassays against raw and treated municipal wastewaters.

Abstract The present study evaluates a battery of marine species-based bioassays against chemically characterized municipal wastewater samples (raw and WWTP treated). We estimated Dunaliella tertiolecta growth rate inhibition ( 24–96 h IC 50 values) , Artemia franciscana immobilization (24h LC 50 values), mussel hemocytes viability and lipid peroxidation enhancement (in terms of neutral red retention assay/NRRT and malondialdehyde/MDA content, respectively) in influent- and WWTP effluent-treated species. We found algal growth arrest and stimulation respectively, almost similar 24hLC 50 values in Artemia sp., and significantly higher adverse effects (in terms of NRRT and MDA levels) in influent-treated mussel hemocytes. Furthermore, the estimation of hatchability, yolk-sac larvae mortality (24–120 hLC 50 ) and spinal deformities (SD) in sea bream Sparus aurata showed slight variations over time, with the lowest LC 50 and SD 50 (representing spinal deformities at 50% of yolk-sac larvae) values to be observed in influent-treated larvae at 120 h. Data interpretation (both chemical and biological) revealed that toxic endpoints, such as NRRT 50 , 96hIC 50 Dun, 120hLC 50 Sparus and 120hSD 50 Sparus, significantly related to WWTP removal efficiency and further mediated by the presence of dominant compounds, such as As and Cr, could be used for identifying main components of toxicity in wastewaters.