Comparison of copper adsorption effectivity in acid mine drainage using natural zeolite and synthesized zeolite

Abstract

Acid mine drainage (AMD) contains a high concentration of various heavy metals and have low pH levels. In this study, the comparison between the use of natural zeolite and synthesized zeolite for Cu2+ removal in AMD was conducted. The adsorbent of natural zeolite was prepared through a chemical activating method by adding NaOH. While, synthesized zeolite was made from coal fly ash using a two-step method, fusion, and hydrothermal process. The AMD used in this study was artificially designed with the concentration of Cu2+ 100 ppm and pH ± 3. The adsorption experiment was carried out using a batch method to observe the influential parameters such as adsorbent dosage, contact time, adsorbent isotherms, and kinetics. The result show that the removal efficiency of Cu2+ for natural zeolite and synthesized zeolite was 98,16% and 93,98 % with optimum adsorbent dose 1,5 g/l and 21 g/l, respectively. The optimum contact time for both adsorbents was 120 minutes. The Langmuir isotherm model fitted the adsorption for synthesized zeolite and natural zeolite, with the maximum sorption capacity of 23,8 mg/g and 30,03 mg/g, and the kinetics model of pseudo-second-order and pseudo-first-order. The result of this study that the good adsorption effectivity synthesized zeolite. Furthermore, both natural zeolite and synthesized zeolite have great potential as a sustainable and economical material for heavy metal removal ion Cu2+ in wastewater.