Tailored ethylenediamine-functionalized graphene oxide membrane on kaolin hollow fibers for pectin concentration.

Pectin is a valuable product that can be extracted from waste fruit peels. Here we propose the use of graphene oxide (GO)-based membranes for pectin concentration. The synthesized GO was functionalized with ethylenediamine (EDA) to molecularly design the GO framework.

Well-dispersed titanium dioxide and silver nanoparticles on external and internal surfaces of asymmetric alumina hollow fibers for enhanced chromium (VI) photoreductions.

Heterogenous photocatalysis is a suitable alternative for wastewater treatment. The supporting of the solid catalyst in a porous material is suggested to facilitate catalyst recovery and reuse. Here we propose for the first time the evaluation of supporting silver (Ag)-decorated titanium dioxide (TiO) catalysts on internal and external surfaces of alumina hollow fibers with asymmetric pore size distribution.

Decoration of alumina hollow fibers with zinc oxide: improvement of the photocatalytic system for methylene blue degradation.

The photocatalytic degradation of methylene blue (MB) in aqueous solutions and under visible light was investigated with dispersed and supported zinc oxide (ZnO) as catalysts. The ZnO catalyst was successfully impregnated in asymmetric alumina hollow fibers by the simple vacuum-assisted dip-coating method. According to energy-dispersive analyses, the photocatalyst was homogenously distributed in the substrate.

Slow release fertilizer prepared with lignin and poly(vinyl acetate) bioblend.

Controlled or slow release fertilizers have been recommended to enhance crop yield, while minimizing environmental and economic issues related from current fertilizer applications. However, alternative biodegradable and non-toxic coating material should be suggested to produce biocoated fertilizers. Here we propose the use of lignin and poly(vinyl acetate) (PVAc) as biocoating materials for preparing slow release urea fertilizer.

Forward Black Liquor Acid Precipitation: Lignin Fractionation by Ultrafiltration.

Lignin recovery from black liquor is an important task for producing valuable chemical products. Acidification processes are currently applied by pulp and paper industries for black liquor treatment, in which two main streams are produced: the precipitated lignin fraction and a lignin-lean black liquor. Membrane filtration is a suitable alternative for lignin recovery from black liquor, but studies on lignin-lean black liquor filtration are scarce.

Photoreduction of chromium(VI) in microstructured ceramic hollow fibers impregnated with titanium dioxide and coated with green algae Chlorella vulgaris.

Here we propose an innovative photocatalytic hybrid system for the reduction of hexavalent chromium (Cr(VI)) from aqueous solutions. The hybrid system was composed of titanium dioxide (TiO) immobilized in the micro-voids of asymmetric alumina hollow fibers and of the green algae Chlorella vulgaris coated on the outer sponge-like layer of the fiber. The photoreduction of Cr(VI) was systematically studied in different systems: single systems with TiO or algae; the synergistic system of algae combined with TiO; and the proposed hybrid system composed of TiO and algae supported in ceramic hollow fibers.

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.