Health Risk Assessment for Reused Backwash Water from Saveh Water Treatment Plant

Background: The increase in population growth, industries and living standards have caused an increasing need for drinking water in many countries. The reuse of treated water and wastewater is one of the most important options to deal with water shortage. To ensure the correctness of this work, it is necessary that the health risk assessment be reassessed during use so that consumers do not face serious problems. In this regard, the assessment of health risks assessment for the water recovered from the backwashing wastewater of the Saveh water treatment plant was investigated. Methods: To reuse the backwash wastewater from the Saveh water treatment plant, the processes of primary sedimentation and coagulation (in the form of a test jar) were investigated. Metals and heavy metals like iron (Fe), aluminum (Al), lead (Pb), Arsenic (As) and cadmium (Cd) were examined to evaluate health risks. The initial settling time was 1 hour, the coagulant used was FeCl3 made in Iran, and heavy metal contents were also measured with an Inductively coupled plasma (ICP) device. Results: The value of HRIs for Al, Fe, As, Pb and Cd in the treated spent filter backwash water (SFBW) with primary sedimentation and coagulation was less than "1" and indicates the absence of risk. Conclusion: The treated backwash wastewater treated with primary sedimentation and coagulation processes as well as raw water of the Saveh have no harmful effects in terms of heavy metals, and its reuse will not pose a risk to the health of the consumer.