STUDY OF EFFECTIVENESS OF USING OPEN LIMESTONE CHANNEL WITH ZEOLITE ADDITION IN PASSIVE TREATMENT OF ACID MINE DRAINAGE ON LABORATORY SCALE

• Main Author: Hilwani, Fajriah
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70726
• Institution: Institut Teknologi Bandung

Acid Mine Drainage (AMD) is one of the problems in mining activity. Management of acid mine drainage is important to be carried out during mining activity and after mine closure to ensure the quality of effluent water from mining. One method of AMD treatment has been widely used is the passive treatment using Open Limestone Channel (OLC). However, in this system there is concern about the iron oxide layer on limestone surface, which could inhibit further dissolution and caused the system failure. Therefor it is necessary to modify an OLC system to reduce iron oxide deposition and increase the effectiveness of the system. In this research, zeolite was used as ion exchanger and expected to reduce pollutants from AMD especially iron ions which would cause armoring on limestone surface. In this study, zeolite control simulations were carried out wuth three channel models, and OLC simulations with six channel models. The simulation used PVC pipe with total length of 200 cm and diameter of 10,16 cm, which was flowed by synthetic acid mine drainage with pH of 2.5 and dissolved metal concentration of 14 mg/L for Fe, 6 mg/L for Mn, and 4.5 mg/L for Al. Based on simulation, zeolite could increase acid neutralization and reduce dissolved metal concentration. Addition of zeolite at the beginning of the LKZ channel could increase pH of 8.15 at the beginning and 7.26 at the end simulation. Metal removal in this channel reached 100% for Fe, 41.2 – 90.6% for Mn, and 100% for Al. In this study, precipitate on the limestone surface was analyzed using SEM-EDS analysis. The results showed that the presence of iron oxide was much less in OLC with zeolite addition. Furthermore, based on modeling using PHREEQC software, it showed that the dominant mineral precipitated on limestone surface was goethite (FeOOH). The amount was also verified to be less in OLC with zeolite addition.