Integrated production of second generation ethanol and lactic acid from steam-exploded elephant grass.

Elephant grass was subjected to steam explosion to enhance cellulose accessibility and convert it into ethanol. After catalyzed pretreatment at 190 °C for 5 min, enzymatic hydrolysis was carried out using high rate of solid loading combined with different enzyme dosages. Assays employing 20% (w/v) solids loading and an enzyme dosage of 20 FPU g-1 substrate led to a yield of 86.02 g glucose released per 100 g potential glucose in the water insoluble solids. This condition was selected to carry out the simultaneous saccharification and fermentation procedure through S. cerevisiae CAT-1, producing 42.25 g L-1 ethanol with a yield of 74.57% regard to the maximum theoretical. The liquor containing C5 and C6-sugars was successfully converted into lactic acid using L. buchneri NRRL B-30929, resulting in 13.35 g L-1 with a yield of 68.21% in relation to the maximum theoretical.

Advanced oxidation processes in the treatment of trifluraline effluent.

The treatment of an effluent from the production of trifluraline was studied using a 1-L, semi-batch, tank-stirred glass reactor for performing three different advanced oxidation processes (photoperoxidation, Fenton, photo-Fenton). A commercial, medium-pressure mercury lamp was used for sample irradiation. The degradation was monitored by measurements of absorptiometric color reduction, UV-visible absorption spectra, and chemical oxygen demand (COD). The obtained results showed that the photo-Fenton process was the most effective treatment for the trifluraline effluent.