Effect of milling time on the performance of ceramic membrane from ball clay for the treatment of nickel plating wastewater

This research reports the development of a membrane from milled ball clay for the treatment of nickel from industrial wastewater. The clay was sieved to 50 μm and milled at different times (10, 20, and 30 h). The raw clay, milled clay, and sintered clay were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis/differential thermal analysis (TGA/DTA), field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET), and particle size distribution (PSD). The milled clays were mixed with a 25 wt% cassava starch, compacted, and fired to a temperature of 1200 °C to produce porous membranes. The fired membranes produced from the milled clay were characterized by multi-point BET and FESEM. In addition, firing characteristics were determined by bulk density, apparent porosity, shrinkage, and flexural strength. Porous membranes produced were subjected to filtration of nickel plating wastewater. The concentration of the nickel in the wastewater and the permeated water was determined using atomic absorption spectroscopy (AAS). BET and the FESEM results show that the pores in the membranes were mesopores with slit shaped-pore and average pore size in the range 23.65–38.86 nm. The concentration of nickel in the permeate water is found to be in the range 0.73–2.39 mg/l. This low-cost membrane will have an application for the treatment of industrial wastewater containing nickel from electroplating industries