A Comparative Analysis of Brick Powder and Limestone as Reactive Media in Permeable Reactive Barriers for Remediation of Fluoride Contamination: Insights from Column Study

Abstract

Abstract Groundwater quality degradation due to natural and human-induced contamination is a pressing concern. Globally, fluoride concentration exceeding the WHO recommendation of 1.5 mg/l in drinking water necessitates effective remediation for safe consumption. Permeable reactive barriers (PRBs) are explored, offering a sustainable alternative to conventional pump and treatment methods. This study investigates the potential of brick powder and limestone for efficient fluoride remediation. Column studies assess material, column height (20-60 cm), and flow rate (1.5-5 ml/min) impacts fluoride removal efficiency via breakthrough curves. Findings demonstrate prolonged column-internal residence times at reduced flow rates, enhancing material efficacy. BDST model parameter was also studied based on the breakthrough point and revealed notably lower brick powder adsorption coefficients than limestone. Brick powder requires a greater critical depth than limestone, affecting PRB’s economic feasibility. Microscopic analyses (SEM, XRD, and FTIR) provide insights into optimal mixture microstructure, phase arrangement, and composition.