Properties of ceramic membranes obtained from kaolinitic clay mixed with palm and mango wastes from Cameroon: Application to wastewater treatment from breweries

This work focuses on the development of new ceramic membranes based on mixtures of low-cost and locally available raw materials such as kaolinitic clay and additives such as palm kernel shells and mango seed shells, which are used as pore-forming agents to increase pore size, and on their efficiencies in rejecting organic and inorganic pollutants from brewery wastewater. The physical and chemical properties of raw materials were characterized via X-ray diffraction, scanning electron microscopy, differential thermal analysis/thermogravimetry, energy dispersive X-ray, and Fourier transform infrared spectrophotometry. Sintering was performed at 1100°C, and the permeability and mechanical properties of circular membranes were determined. The membrane filtration operation was used to assess the physicochemical parameters of the wastewater. The membrane composed of 85% kaolinite and 15% mango seed shells showed the best performance. The effective treatment of the breweries wastewater reduced the level of contamination by organic pollutants in the discharge water, with a reduction in concentration from 700 to 14 mg O₂ L^‒1 of chemical oxygen demand and 250 to 06 mg O₂ L^‒1 of biological oxygen demand for 5 days, representing elimination rates of 98% and 97.6%, respectively. The treated water is alkaline, with a reduction in pH from 10.79 to 7.77. Suspended matter, turbidity, and electrical conductivity had removal rates of 88%, 90.6%, and 99.8%, respectively. A significant reduction in the salinity of this wastewater contributed to sodium and chloride ion rejection rates of 93% and 79%, respectively, which is an important result for good reuse of the treated water in agriculture and domestic work.