The application of the Fluidized-Bed Crystallization process to recover iron and copper simultaneously as binary oxide particles from synthetic wastewater Nicolaus Nezha Nunez Mahasti, Yao-Hui Huang
Chemical Engineering Department, National Cheng Kung University, Taiwan
Abstract
The simultaneous recovery of iron and copper from synthetic wastewater as binary oxide particles of FeIII0.66CuI0.33@SiO2 was successfully experimented with through the Fluidized-bed crystallization (FBC) process. The operating parameters, including pH and cross-sectional surface loading, were optimized to obtain the highest crystallization efficiency. The different seed materials and organic contaminations were tested. The potential disposal cost-down was also calculated. Under the optimum conditions of pH = 7.5 - 8.5, [Fe(II)]in / [Cu(II)]in = 2 / 1, and total inlet metal concentration of 3 mM. The crystallization ratio (CR) reached 90% for both iron and copper with the corresponding total removal (TR) of >99%. There was no significant effect of removal efficiency in the different supported seed materials. However the CR and TR for iron decreased to 29% and 44.57%, respectively and the CR and TR of copper also decreased to 32.1% and 39.8%, respectively under the contamination of chelating agents that was represented by EDTA. XRD and XPS analysis clearly shows that the iron oxide and copper oxide coated species exist as α--FeOOH and Cu2O. FBC is a promising process to recover heavy metal-containing wastewater as low moisture particles that successfully reduced sludge production and cut disposal costs by up to 36%.
Keywords: Fluidized-bed crystallization- binary metal - oxide- cross-sectional surface loading- crystallization ratio
