Application of modified membranes in drinking water treatment

This paper presents filtration results obtained with commercial acetate membrane with a pore diameter of 0.45 μm, unmodified and modified with TiO2, bearing in mind drinking water treatment. The experimental filtration set-up that was used consisted in the gravitational filtration system, whereas the accomplished tests that were endured consisted of hydraulic permeability of the modified and unmodified membranes, treatment of polluted water with E. coli bacterium, color removal, turbidity and free chlorine. The results of hydraulic permeability showed similar flux for all membranes at the end of the experiments, between 25 and 30 kg·m-2· h-1. The retention results for color, turbidity and E.coli bacteria are comparable.Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologi

Effects of coconut granular activated carbon pretreatment on membrane filtration in a gravitational driven process to improve drinking water quality

This study evaluates the performance of a polymeric microfiltration membrane, as well as its combination with a coconut granular activated carbon (GAC) pretreatment, in a gravitational filtration module, to improve the quality of water destined to human consumption. The proposed membrane and adsorbent were thoroughly characterized using instrumental techniques, such as contact angle, Brunauer–Emmett–Teller) and Fourier transform infrared spectroscopy analyses. The applied processes (membrane and GAC + membrane) were evaluated regarding permeate flux, fouling percentage, pH and removal of Escherichia coli, colour, turbidity and free chlorine. The obtained results for filtrations with and without GAC pretreatment were similar in terms of water quality. GAC pretreatment ensured higher chlorine removals, as well as higher initial permeate fluxes. This system, applying GAC as a pretreatment and a gravitational driven membrane filtration, could be considered as an alternative point-of-use treatment for water destined for human consumption.Fundação Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Drinking water treatment in a gravimetric flow system with TiO2 coated membranes

This paper presents filtration results for drinking water treatment obtained with a commercial cellulose acetate membrane of 0.45 μm pore diameter, with and without TiO2 coating. The deposition of titanium dioxide thin films onto membrane surface was made by pulsed-frequency d.c. reactive magnetron sputtering at room temperature from a high purity Ti target in Ar/O2/N2 atmosphere, at different conditions for cathode current and for deposition time. The proposed membranes were used in a filtration system driven by gravitation without the requirement of energy supply. The obtained results showed that the proposed system is able to remove color and turbidity from raw water. Besides, the modified membrane presented better results than the neat one regarding to membrane fouling and chlorine removal.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG