Compact carbon-based membrane reactors for anaerobic biodegradation of azo-dyes from wastewater

Identifier:  TDX:2431

Handle: https://hdl.handle.net/20.500.11797/TDX2431

Authors:  Giménez Pérez, Alberto

Abstract:
The azo dyes are considered toxic and recalcitrant contaminants to conventional processes implemented in municipal wastewater treatment plants. The use of carbonaceous materials has proven beneficial to increase the performance of the degradation processes because it acts as an electron carrier between the oxidation of a secondary source of carbon and the reduction of the azo dye. Therefore, this thesis proposes the use of an innovative system combining the electron carrier and an retention system in a single element. This is possible by preparing carbon membranes supported on ceramic elements. These materials present pores in the range of the nanofiltration so ensuring the retention of all biological compounds implied in this process. Furthermore, the carbon layer facilitates the electrons transport in the same way as previous reported systems such as carbon packed beds. The membrane synthesis requires specific conditions discussed throughout the thesis in order to prepare a uniform surface and completely covered with carbon. This novel system allows similar degradation rates of Acid Orange 7, 80-100% (32 g • m-3 • day-1) as previous studies reported in the literature. Furthermore, puntual severe cases of membrane fouling can be efficiently solved by conventional cleaning techniques widely used in this field. Throughout the thesis membrane reactors with different configurations carbonaceous materials are extensively studied.