Investigation the applicability of eggshell for the treatment of a contaminated mining site

Abstract

Acid mine drainage (AMD) is a major environmental problem particularly for abandoned mining site, and many approaches and techniques have been developed for its management and rehabilitation. The abandoned Çan lignite basin enriched with sulfur minerals bearing rocks located in the NW Turkey, and its vicinity has been known as an AMD contaminated mining site for fifty years. Therefore, in order to investigate the applicability of eggshells for rehabilitation of this region, acidic water and solid samples were collected from acidic ponds and waste deposits for performing laboratory experiments. Besides sampling, pH and conductivity were also measured from different acidic ponds, and they are generally around 3 and 5717μS/cm, respectively. In addition, the dissolved heavy metals as contaminants have been identified. In order to remove heavy metals and other pollutants from these contaminated ponds and stop further AMD generation, the grinded eggshell (−0.125mm) was used as a low-cost material in batch experiments and column tests. During batch tests, the effects of the amount of the eggshell, 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 Çan mining site. The outcomes of the present study reveal the applicability and removal efficiency of eggshell technique as a low cost material for remediation abandoned mining sites under AMD hazard.