Acute toxicity from a prototype equipment of water separation through solar distillation on Daphnia magna Straus, 1820

The use of sustainable forms of energy should be encouraged, considering the damages that usual sources of energy can cause to our planet, which are often irreversible for decades or centuries. Despite the sun being the main source of energy on Earth, in tropical countries like Brazil, this kind of energy could be better exploited. The present work aims to evaluate the toxicity of purified water and a solution of CuSO4, after decontamination in a prototype equipment of solar distillation of wastewater (due to separation of condensed water from non-volatile substances), in order to test the efficiency of the equipment. Thus, acute toxicity tests were performed with Daphnia magna. The EC50 – 48 h values (the median concentration of a substance that causes effect to fifty percent of organisms) for deionized water and solution of 1 mg L-1 of CuSO4, both after distillation, were 19.61% and 17.08%, respectively. Results indicates that the final samples from the equipment were toxic to D. magna, and therefore, with a potential risk for the freshwater biota. Based on that, it is recommended improvements in the equipment structure, to reduce toxicity, since it occurred probably by contamination of the structures of the equipment itself.