Malachite green dye removal using ceramsite-supported nanoscale zero-valent iron in a fixed-bed reactor

Abstract

In this study, we prepared and characterized ceramsite-supported nanoscale zero-valent iron (nZVI). Malachite green (MG) dye removal from aqueous solutions using a fixed-bed reactor packed with the above composite material was investigated. This research was carried out according to the prophase study of the preparation and characterization of ceramsite material for water treatment using sintering method from solid wastes. The results indicated that ceramsite could be loaded with nZVI, mainly because of its magnetic property. With the decrease in the initial concentration and influent flow rate or the increase in the reaction temperature, the breakthrough curve became less steep. Meanwhile, the breakthrough and saturation points gradually shifted rightward. When the initial concentration was 10 mg·L−1, the reaction temperature was 25°C, and the influent flow rate was 5 mL·min−1, the breakthrough curve presented an irregular “S” shape, the breakthrough and saturation times were 230 and 515 h, respectively. The characterization of MG dye-containing wastewater treatment using ceramsite-supported nZVI in a fixed-bed reactor by employing the Yoon-Nelson kinetic model was superior to those using the Thomas and Adams-Bohart kinetic models, with R 2 > 0.96.

Keywords

• ceramsite-supported nzvi
• fixed-bed reactor
• dye wastewater
• breakthrough behavior
• kinetic analysis