Performance Simulation of Open Limestone Channel Based on Water Quality Parameters and Armoring
Ir. Ridho Qurniawan, S.T., M.T. Jerry Dwifajar Prabowo, S.T., M.T. Andrieanto Nurrochman, S.T., M.SC.ENG

Bandung Islamic University

Abstract

This study evaluates the performance of an Open Limestone Channel (OLC) as a passive treatment method for synthetic acid mine drainage (AMD), focusing on water quality improvement and the formation of sediment layers (armoring) on limestone surfaces. The simulation used synthetic AMD with extreme conditions (pH 0.29- Fe = 50 mg/L), which was flowed through a 1-meter OLC channel with a 2% slope using limestone particles sized 2.38-3.36 mm. System performance was assessed by monitoring pH, TDS, ORP, EC, and dissolved metal concentrations, as well as by conducting visual and microscopic analysis of armoring using optical microscopy and Scanning Electron Microscopy (SEM). Results showed a significant pH increase (&#916-pH > 6) within 15 minutes and the formation of yellow-brown iron oxide precipitates on limestone surfaces. Armoring was found to be more pronounced in unmodified channels, indicating a decline in OLC efficiency over time. The study contributes to a better understanding of neutralization mechanisms, surface fouling, and performance degradation, offering recommendations for improved OLC design.

Keywords: open limestone channel, acid mine drainage, armoring, iron oxide

Topic: Material Engineering