Treatment of industrial wastewater of alcohol factories using a particle trap system and their potential for aquaculture using Daphnia (Daphnia pulex) and Zebrafish (Danio rerio) as model bioindicators

Considering the drought and lack of water in recent decades, effluent reuse has been suggested as an efficient way to save water sources. Also, reducing the amount of sewage before releasing it into the environment is necessary to decrease threats to human and aquatic organisms. In recent years, due to the emergence of the COVID-19 epidemic and following the massive production of alcohol, the discharge of wastewater from these factories has increased. In this research, the performance of a particle trap system (PTS) was examined in treating the effluents of an alcohol factory as vinasse and stillage and the treated water with different concentrations of the wastewater was used for Daphnia (Daphnia pulex) and Zebrafish (Danio rerio) as model bioindicators. The performance of PTS in reducing COD, BOD, and TSS for vinasse was 96.90, 97.44, and 88.43% and for stillage was 95.69, 96.77, and 90.15%, respectively. Based on the results, the LC50 of vinasse for zebrafish and daphnia was 0.63 and 0.76%, and the LC50 of stillage for zebrafish and daphnia was 0.6 and 0.65%, respectively. The mortality rate of daphnia and zebrafish was different based on wastewater concentration and duration of exposure. In high exposure concentrations, which were usually above 3%, death occurred in a shorter period of time. In conclusion, the PTS is an efficient and inexpensive system for the purification and recycling of effluent from alcohol factories.