Adsorption of Metal Ions from Fine Coal Tailings Dump Waste Water using Bio-char

Abstract

Coal mining operations produce large amounts of tailings which contains heavy metals. Heavy metals such as cadmium (Cd) can cause environmental problems. The adsorption capacities of biochars produced from spent coffee beans and brewery waste were explored for the removal of Cd from single and multi-component solutions. The biochars were prepared by hydrothermal liquefaction (HTL) and characterized by scanning electron microscope analysis (SEM) and Fourier transform infrared microscopy (FTIR). The developed adsorbents were utilized in batches of pre-treated and untreated biochar for the removal of Cd metal ions. The pre-treatment was done through surface impregnation with sodium dodecyl sulfate (SDS). The pseudo second order kinetic model was suitable in this study to predict the adsorption capacity of the pre-treated and untreated biochar; it was found that the pretreatment of biochar with SDS contributed to increase its adsorption capacity from 4.824 to 10.672. The pre-treated and untreated biochar can be used for the treatment wastewater contaminated with Cd. Keywords— Adsorption, biochar, coal tailing, cadmium, surface impregnation