Determination of toxicological effects of Konya urban wastewater treatment plant and organized industrial zone wastewaters

industrial chemicals. One of the reasons for the detection of pollutants in influent is detected by that they cannot be completely removed by conventional wastewater treatment technologies. For this reason, toxicity assessments of wastewater is important due the prevention of their adverse affect on living organisms and environmental pollution. Considering that there are toxic effects in wastewater and the possible harmful effects of these effects on living things and the environment, it is aimed to investigate the toxic effects in wastewater and to reveal the effects. In this study, influent and effluent samples were taken from Konya Urban Wastewater Treatment Plant (Konya Urban WWTP) and Konya Organized Industrial Zone Wastewater Treatment Plant (KOI WWTP) as two different wastewater samples to determine their toxic effects. Due to the their ability to represent different trophic levels in aquatic and terrestrial ecosystems, and their different sensitivity. Lepidium sativum (known as watercress), Fish bioassay (ZSF) was conducted to determine toxicity levels and marine bacteria Vibrio fischeri bioindicators were used in toxicity tests to evaluate acute toxicity of wastewater. Consequently, according to Lepidium sativum toxicity test results it was determined that root inhibition is higher than hypocotyl inhibition in the influent and effluent of the Konya Urban WWTP and KOI WWTP. The influent and effluent samples of Konya Urban WWTP were classified as 'toxic' to root and 'less toxic' to hypocotyl. Toxic effect difference is between influent and effluent samples of KOI WWTP is less and it classified as 'less toxic' for roots and hypocotyl. As a result of applying fish bioassay (ZSF) toxicity test to influent and effluent samples of KOI WWTP, it was determined that influent is more toxic than effluent because it contains high amounts of heavy metals and pollutants. In addition, it was observed that the effluent sample meets the discharge standard according to SSKY Table 19. In the Vibrio fischeri toxicity test, the same dilution ratios (6.25%, 12.5%, 25%, 50%) were applied to four different wastewater samples and classified according to the toxic unit values corresponding to different inhibition percentages. Influent of Konya Urban WWTP was classified as 'toxic' and effluent as 'non-toxic'. Influent of KOI WWTP was classified as 'toxic' and effluent as 'less toxic'. At the end of this study, it was concluded that all three tests can be applied in the toxic evaluation of wastewater, and different sensitivities that can be observed for different wastewater characterizations.