Toxicity study of UV/ZnO treated solution containing Reactive blue 29 using Daphnia magna as a biological indicator

Effluents from textile industry are a major source of environmental pollution, especially water pollution. One of the commonly used nanoparticles is zinc oxide (ZnO). In this study, the toxicity of solutions containing the Reactive blue 29 dye after nano-catalytic process UV/ZnO using the model organism Daphnia magna (D. magna) was studied. This is a fundamental - practical study, which was done at laboratory scale. D. magna is considered as an indicator of textile industry wastewater's toxicity. First, biological tests were performed according to the Standard Methods for the Examination of Water and Wastewater. Results showed that the LC₅₀ values at 24, 48, 72, and 96 h were 80.27, 62.26, 49.42, 32.64 mg/L, respectively. Advantages of this technique includes: •The results of this study can be used for selection of the appropriate methods for the removal of the dyes from wastewater.•Possible hazard of toxicity exists to ecosystems in any receiving system, highlighting the need for evaluating the toxicity of industrial dyes.•The results of this study show that Daphnia magna is a suitable indicator for evaluating the toxicity of contacted oxidizing nanoparticles with a Reactive blue 29 dye.