Performance of a Zeolite-Filled Slow Filter for Dye Removal and Turbidity Reduction

Ever-increasing global water shortages necessitate more advanced and cost-effective water purification methods. Herein, a novel slow filtration system using natural raw zeolite is proposed as an alternative to traditional quartz sand as a filter medium. The system demonstrates excellent performance in reducing turbidity and removing methylene blue (MB). The natural zeolite-based filtration system (filter bed depth of 70 cm) completely adsorbed 30 ppm MB at a filtration velocity of 0.2 m/h, maintaining its performance up to 2 months. The highest adsorption capacity (q_max) for MB of natural zeolite was 8.32 mg/g for the 0.3 mm fraction and 13.84 mg/g for the 0.1 mm fraction. The slow filtration process demonstrated high turbidity removal efficiencies, achieving 98.53% with the natural zeolite filter and 98.97% with the quartz sand filter, indicating the effectiveness of both media in improving water quality. This study highlights the potential of the natural zeolite-based slow filtration system as a versatile and effective water treatment solution.