Water filtration performance comparison of sayong ball clay membrane produced by gel casting and spark plasma sintering methods

Abstract

Some membranes are made of ceramic material due to their excellent properties that can withstand almost any feed conditions and possess natural adsorption agents for heavy metal removal. However, due to depleting of membrane resources and the high cost of raw material such as alumina, searching for alternative materials from natural resources attract researchers’ attention. Natural Sayong ball clay is abundantly available in Malaysia and has great potential applications such as ceramic membrane but their properties and characteristics are scarcely reported in the literature. This study aimed to evaluate the effect of monomers ratios of Methacrylamide and N, N'- Methylenebisacrylamide (6:1-14:1) and sintering temperatures (550-1050°C) on the ceramic membrane properties. Gel casting and spark plasma sintering were used to fabricate the membrane and control their pore size. The investigation started with the raw powder characterizations by field emission scanning electron microscope (FESEM), x-ray diffraction (XRD), x-ray fluorescence (XRF), and particle size analyzer before being used to fabricate the membranes. After the fabricated membranes have been characterized and tested physically and mechanically, the performance of membranes was then tested with water filtration and quality analysis. It was found that the microstructures and properties of the ceramic membrane were influenced not only by the ratio of monomers during the gel casting process but also was found to be dependent on the spark plasma sintering temperatures. Membranes fabricated by gel casting showed that microstructures of the sintered membranes were highly porous (30-46%) which could not provide enough modulus of rupture (MOR) (20-36 MPa) but vice-versa in the case of membranes fabricated by spark plasma sintering method which achieved maximum MOR of 96 MPa with zero % of porosity. The gel casting membrane with the highest ratio of monomers of 14:1 gave the highest copper ions removal efficiency of 87%, color removal percentage of 99.3%, hardness reduction percentage of 90.5%, and nickel ions removal percentage of 59% while the spark plasma sintering membrane with the lowest sintering temperature at 650ºC gave the highest copper ions removal efficiency of 83%, colour pigment removal percentage of 99.5%, water hardness reduction percentage of 91.2%, and nickel ion removal percentage of 18.2%. It was found that the ball clay membrane was best fabricated with gel casting with a 14:1 ratio of monomers in terms of water qualities.