Date of Graduation
Bachelor of Science in Chemical Engineering
Committee Member/Second Reader
The team researched, designed, and economically analyzed a full-scale adsorption column system to be applied in mining processes that leave high amounts of fluoride in their effluent. This system was designed to remove fluoride from water saturated with calcium sulfate, as calcium sulfate is present in high amounts in certain mining processes. Currently, high density sludge (HDS) is commonly employed to reduce fluoride concentrations, but due to solubility limits the sludge treatment cannot lower fluoride below 10 mg/L (ppm). The current enforceable EPA standard for discharged water is at 4 mg/L (ppm), although mining companies anticipate that this standard will soon be lowered to 2 ppm. The team was tasked with designing a process to lower 10 ppm fluoride down to 2 ppm.
The team investigated various methods such as precipitation, ion exchange, and reverse osmosis to remove fluoride from the system. These methods were not cost-effective and did not produce environmentally friendly byproducts. The team ultimately presented the solution of bone char as an adsorbent, with a byproduct that can be safely applied as a soil amendment. A full-scale facility with two adsorption columns was designed to treat 1000 gpm of water.
Adsorption, Bone Char, Fluoride, Water Treatment, Sulfur, Soil Amendment
Le, K., Damian, A., Johnson, M., Phan, E., Golman, C., Dopp, M., & Payne, J. (2020). Removal of Fluoride from Mine Water via Adsorption for Land-Applied Soil Amendment. Chemical Engineering Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/cheguht/159