Investigation of the hormesis/toxicity potential of Manisa (Turkey) urban wastewater treatment plant by using Selenastrum capricornutum Printz

The environmental impacts of urban and industrial wastewater in aquatic environments have been researched for a long time. In this study, the algal inhibition effect on influent and effluent belonging to the urban wastewater treatment plant in Manisa, with a population over 250.000, are researched with a 72-h Selenastrum capricornutum (Printz) test. The measurement of COD, BOD, SS and pH parameters of the water from the influent and effluents in the plant with 31000 m3/day are conducted as part of National Water Pollution Control Regulations (NWPCR, 31.12.2004; 25687). The trials took place with four repetitions in a range of 10-1 -10-4, and seven different dilution rates. The effect of wastewater samples on the growth of S. capricornutum species is defined as % inhibition with a size of cells m1 -1. As a result of this research; it is determined that, in all the dilution rates of the influent in the wastewater treatment plant, it inhibits the growth of the species (TU-Class IV), and that it shows hormetic effects in low concentrations of the effluent; however, in high concentrations, it inhibits the growth of the species (TU-Class III). It is seen that seasonal variations of river flowrate have an effect on the toxicity effect value (IF).