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Electrocoagulation-flotation (ECF) is a technique that combines the benefits of coagulation, flotation, and electrochemistry and can be very efficient in removing contaminants present in drinking water. The objective of this study was to determine an ideal configuration for an ECF reactor for the treatment of drinking water. A fractional factorial experimental design (26-2) was performed using initial pH, electric current, electrolysis time, agitation, inter-electrode distance, and a number of electrodes as variables. Subsequently, a central composite rotatable design was conducted using the most significant variables of the fractional design, which were initial pH, electrical current, electrolysis time, and a number of electrodes. The response variables analyzed were color removal, electrode mass consumption, sludge production, and energy consumption. The ECF experiment was performed in a batch system with aluminum electrodes in a monopolar parallel configuration. The ECF technique was adequate for treating drinking water with the best treatment conditions at an initial pH of 8.5, an electrical current of 0.25 A, electrolysis time of 12.5 min, and 3 electrodes. Under these conditions, the efficiency of color removal was 86.42%, electrode mass consumption of 0.019 kg m-3, sludge production of 0.087 kg m-3, and energy consumption of 0.21 kWh m-3. [ABSTRACT FROM AUTHOR]

In this research it was evaluated the production of biobutanol by Clostridium beijerinckii NRRL B-592 using sweet sorghum juice as carbon source. Operational variables, like pH and initial inoculum size, as well as supplementation of industrial media with yeast extract and tryptone, were evaluated. The maximum butanol obtained was 2.12g kg-1 using 12.5% of inoculum size, 0.05g 100mL-1 of tryptone and 0.1g 100mL-1 of yeast extract and initial pH of 5.5. The main contribution of this research was to show a systematic procedure for development of a low cost industrial media for biobutanol production from sweet sorghum. [ABSTRACT FROM AUTHOR]