Investigation of usability of red mud for dye removal by adsorption method

The increase in technology and population also increases the need for raw materials. For this reason, the amount of minerals produced is increasing day by day. The non-economic part of the produced ore is stored, waiting to be used either in the rehabilitation of the field or when it will have an economic value after the mine has completed its life. However, these processes cause other problems, primarily environmental, in the medium and long term. The use of a plant waste in another waste disposal is an issue worthy of evaluation from both environmental and economic perspectives. For this reason, the usability of red mud, which is the solid waste of aluminum production plant, in paint removal was investigated. In this thesis, raw red mud was used as adsorbent. Initial malachite green dye concentrations were taken as 100 ppm and 200 ppm. In temperature measurements (25°C, 40°C and 60°C), samples were taken at intervals and dye concentration was followed by using a UV-vis spectrometer. The contact time between red mud and malachite green was kept constant at 180 minutes. Based on the data obtained from 100 ppm malachite green dye solution, the adsorption capacity was calculated as 17,783 mg/g and 98,998 mg/g, respectively, according to Langmuir and Freundlich isotherm models. In 200 ppm malachite green dye removal, the adsorption capacity was found to be 57,604 mg/g and 202.55 mg/g, respectively, according to Langmuir and Freundlich isotherm models. Adsorption kinetic models were also examined within the scope of the study and it was determined that the study was suitable for the pseudo-second-order kinetic model. Keywords: Red mud; malachite green; removal dye; Langmuir; Freundlich