The Adsorption Characteristics of Heavy Metals in Acid Mine Drainage from Abandoned Tin Mines on Lightweight Expanded Clay Aggregate (LECA)

Abstract

Abandoned tin mines produce acid mine drainage in their water basin. If not treated well, it will damage environmental ecosystem by entering rivers or other water bodies. This acid mine drainage is attempted to be remediated by adsorption technique. The adsorbent used in this study is Lightweight Expanded Clay Aggregate (LECA) because its base material is natural clay. LECA is commonly used for hydroponics and constructions. LECA is made from natural clay that being heated at temperature over 1100°C. This study aims to determine how significant LECA in adsorbing metals in acid tin mine drainage. This research used two materials namely LECA and tin acid mine drainage. Both materials were contacted for two days in shaker bath. The results of this study were the adsorbing Fe(II) and Cu(II) on LECA could be approached by the Langmuir-Freundlich (LF) combined model where the Cµ,max are 0.406 and 0.020 mg/g of adsorbent, respectively. Unlike the other two metals, Sn(II) was more likely to experience precipitation instead of adsorption because of increasing of pH value. The conclusion, heavy metals in tin acid mine drainage could be remediated well by using LECA.