Objectives In this research. individual toxicity evaluation of heavy metals (Hg2+. Cr6+. Cd2+) was performed using a semi-continuous type bioreactor based on changes in the activity of sulfur oxidizing bacteria(SOB). https://safeersappliancers.shop/product-category/faber-galileo-duct-out-induction-hob-340-0540-965-a-4-hob/