Development of asymmetric ceramic membranes for dairy wastewater treatment - A comparison between co-sintering and conventional firing process

Ceramic membranes have high potential for wastewater recovery. However, the high cost of raw materials and the high energy consumption for manufacturing, limit their use. This study aimed to prepare ceramic membranes using kaolin and alumina, emphasizing firing in a single step. On the support, corn starch was used as a porogenic agent and to evaluate the performance of the membrane, a simulation was used for the dairy industry effluent. The supports were manufactured by the extrusion process, which were sintered (1100, 1200 and 1300 degrees C), for the analysis of their properties. A suspension was applied to the inner surface of the green supports, and the cosintering process was employed. The supports containing 15 % corn starch sintered at 1100 degrees C showed high porosity (48 %), pure water permeate flux of 1385 L/h.m2 at 2 bar and mechanical strength of 8 oa. The active layer exhibited pore sizes that indicate that the membrane can be used in the microfiltration process, with a permeate flux of 897 L/h.m2. The membrane showed adequate microfiltration performance for the removal of components present in the milk solution and responsible for the turbidity of the permeate, with a permeate flux stabilized at 30 L/h.m2.