Recovering Zinc from electroplating wastewater by crystallization in a pellet reactor

A pellet reactor (PR) was used to investigate the ability for zinc recovery from electroplating wastewater. The pellet reactor is a fluidized bed reactor, in which the nucleated precipitation of heavy metals occurred on the surface of seeding material. The zinc removal efficiency was 75% at molar ratio [CO3 2-]/[Zn2+] of 2.5, the flowrate of 16 L/h, sand’s diameter of 0.25 – 0.5 mm, and sand’s mass of 50 g. The elemental analysis of zinc carbonate and zinc hydroxide crystallization was analyzed by X-ray energy dispersive spectrometer (EDS) and the surface was characterised by Scanning electron microscope (SEM) to get the morphological observation of the pellets after 38-day operation. This study demonstrated that the fluidized bed reactor can be considered a feasible method for zinc removal efficiency from electroplating wastewater to achieve sustainable development.