This study characterized wastes from scheelite and columbite-tantalite mining, as well as kaolin processing, to produce microfiltration membranes for wastewater treatment using a fast-sintered process. After characterization, the wastes were mixed with clays, pressed, and sintered at low temperatures of 1050 and 1100 °C. The resulting membranes exhibited pore size distributions ranging from 3 μm to 180 μm and flexural strengths exceeding 14 MPa. In a crossflow filtration system, permeate fluxes ranged from 177 L/h.m2 to 228 L/h.m2 at 2 bar, with permeabilities from 99 to 130 L/h.m2 bar depending on the waste content. Membranes with smaller pore sizes effectively removed 90% to 96% of turbidity from a water/clay suspension containing micrometric clay particles. This approach demonstrates that rapid sintering of ceramic membranes from mining waste can effectively reduce environmental impacts and energy costs, providing a sustainable solution for wastewater treatment.

A highly efficient NiFe2O4/TiO2 nanofibrous photocatalyst was prepared by a simultaneous solution blow spinning method. The hybrid fibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and magnetometry. The photocatalytic properties were evaluated using Crystal violet (CV) and Congo red (CR) dyes under visible light irradiation. Fibers calcined at 600 ºC and 700 ºC showed the highest CV decolorization (77%). On the other hand, for CR, the best performance was encountered with the photocatalysts heat-treated at 500 ºC, which exhibited photocatalytic degradation of 87% after only 30 min of visible light irradiation. The high reaction rates (0.018 to 0.067 min-1) explain the fast decolorization yielded by the combined effect of adsorption and photocatalytic processes. Moreover, recyclability assays showed stable CR dye efficiency after five recycling cycles. Therefore, the NiFe2O4/TiO2 nanofibers present a high potential for application in the decolorization treatment of wastewater from the textile industry.