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This study focuses on the development of porous ceramer and SiOC composites which are suitable for microfiltration applications, using a mixture of polysiloxanes as the preceramic precursor. The properties of the membranes—such as their pore size, hydrophilicity, specific surface area, and mechanical resistance—were tailored in a one-step process, according to the choice of pyrolysis temperatures (600–1000 °C) and the incorporation of micro- (SiC) and nanofillers (TiO2). Lower pyrolysis temperatures (<700 °C) allowed the incorporation of TiO2 in its photocatalytically active anatase phase, enabling the study of its photocatalytic decomposition. The produced materials showed low photocatalytic activity; however, a high adsorption capacity for methylene blue was observed, which could be suitable for dye-removal applications. The membrane performance was evaluated in terms of its maximum flexural strength, water permeation, and separation of an oil-in-water emulsion. The mechanical resistance increased with an increase of the pyrolysis temperature, as the preceramic precursor underwent the ceramization process. Water fluxes varying from 2.5 to 370 L/m2·h (2 bar) were obtained according to the membrane pore sizes and surface characteristics. Oil-rejection ratios of 81–98% were obtained at an initial oil concentration of 1000 mg/L, indicating a potential application of the produced PDC membranes in the treatment of oily wastewater.

In this study, Ca-loaded macroalga Pelvetia canaliculata was investigated as a natural cation exchanger for barium removal. A mass action law was able to fit satisfactorily the equilibrium data for the ternary mixture (Ba 2+ /H + /Ca 2+), resulting in selectivity coefficients of Ba H K = 6.88/0.41 and Ca H K = 3.08/0.03, for carboxylic/sulphonic groups. In the packed bed column, the service capacity was 237 bed-volumes (BV), treating 14.2 L of influent with a feed concentration of 2.9 mEq Ba 2+/ L, until the breakthrough point of 0.07 mEq Ba 2+ /L. Elution efficiency near to 100% was achieved using 5 BV of 1.0 M HCl in counter-flow direction. A dynamic mass transfer model, considering equilibrium given by the mass action law, linear driving force (LDF) approach to describe the intraparticle mass transfer resistance and the stagnated film resistance described well the breakthrough profiles for all species obtained in a packed bed column.