Use of Claystone, Zeolite, and Activated Carbon as a Composite to Remove Heavy Metals From Acid Mine Drainage in Coal Mining

Abstract

Acid mine drainage is an environmental issue impairing water sources globally. Efficient and continuous treatment in mining regions is urgently required. Therefore, this research aimed to evaluate the use of claystone from coal overburden, zeolite, and activated carbon from coconut shell as a composite to remove Fe and Mn from acid mine drainage. XRD, BET, and SEM characterized the adsorbent. The X-Ray Diffraction analysis showed the types of mineral in claystone were kaolinite, zeolite: mordenite, and activated carbon: cristobalite. Composite made with three ratios (Claystone:Zeolite:Activated carbon) = 50:25:25; 25:25:50; and 25:50:25. According to the surface area analyzer, composite with a 25:25:50 ratio had the largest surface area (62,44 m2/g). SEM-EDX analysis showed that composite had porous morphology and active sites such as Al and Si. Adsorption was carried out using a hot plate stirrer with various contact time: 30,60,90,120 and 150 minutes. The results showed that composite succeeded in increasing pH from 2.6 to 7.0 and reducing Fe concentration from 13.006 to 0.1484 ppm (98,86%) and Mn concentration from 30.59 to 20.283 ppm (33,69%). The adsorption capacities of the composite were 1,286 mg/g for Fe and 1,031 mg/g for Mn. It can be concluded that composite is a good adsorbent for removing iron from acid mine drainage.