The Rehabilitation of Acid Mine Drainage at an Abandoned Mining Site by Utilizing Eggshell as Adsorbent

摘要

Acid mine drainage (AMD) is a major environmental problem particularly for abandoned mining site, and many approaches and techniques have been developed until now for its management and rehabilitation. The abandoned Can lignite field basin, which enriched with sulphur minerals bearing rocks, located in the province of Canakkale, Turkey, and its vicinity has been known as an AMD contaminated mining site for fifty years. Therefore, in order to investigate the effect of eggshells on rehabilitation characteristics of this region, wastewater and solid samples were collected from acidic ponds and waste deposits to be used in laboratory experiments. Besides sampling, pH and conductivity were also measured from different acidic ponds, and they are generally around 3 and 5717 uS/cm, respectively. In addition, heavy dissolved contaminant concentrations have been identified. In order to remove heavy metals and other pollutants from these contaminated ponds and stop further AMD generation within lignite and spoil materials and, the grinded eggshell (minus 0.125 mm) was used as a low-cost adsorbent in adsorption experiments and column tests. During adsorption tests, the effects of the amount of the adsorbent, the amount of contaminated water and contact time on adsorption were investigated by monitoring rising in pH value until 6.5, as well as by comparing initial and final concentrations of dissolved contaminants. Consequently, after all of testing and related analyses, the required amount of eggshells was determined for acidic ponds found at abandoned Can mining site. The outcomes of the present study reveal the applicability and removal efficiency of eggshell technique as a low cost adsorbent for remediation abandoned mining sites under AMD hazard.