Valorization of the Vicia faba mucilage on textile wastewater treatment as a bio-flocculant: process development and optimization using response surface methodology (RSM).

The Vicia faba membranes are an abundant and a low cost product. In the present research paper, the extracted Vicia faba mucilage was tested as an eco-friendly flocculant for textile wastewater treatment. Its performance as flocculant, in decolorization, chemical oxygen demand (COD) removal and the concentration of total suspended solids was checked. The natural extracted product was characterized using infrared spectroscopy. The total sugars were determined in the extracted product. The effect study, followed by an optimization and modeling analysis, of some experimental parameters on the coagulation-flocculation performance, using Vicia faba mucilage (as a flocculant), combined with aluminum sulfate (as a coagulant), showed that the best conditions for the flocculation process were pH of the effluent about 7, flocculant dose about 6.75 mg/L, flocculation mixing time about 3 min and flocculation mixing speed about 30 rpm, leading to a decolorization equal to 92.32%, COD removal of about 97.52% and total suspended solids of about 15.3 mg/L. A comparison study between the flocculation performance of commercial reagents and the bio-agent showed that the natural product presented a good flocculation performance.

The Effect of Vitis vinifera L. Leaves Extract on Leishmania infantum.

Vitis vinifera L.is a traditional Asian herb widely used for different health problems. In the present research, the ethanolic and the aqueous extracts of Vitis vinifera L. leaves collected from shrub, grown in Tunisia, were prepared and evaluated for the antileishmanial activity against Leishmani ainfantum promastigotes. The inhibitory concentration 50 (IC50) was determined and the results showed that the etahnolic extract is more active than the aqueous one (IC50= 0.108 mg/mL). Microscopic observations showed that the ethanolic extract promoted the destruction of cytoplasmic and nuclear membranes of Leishmani ainfantum promastigotes and altered the overall shape of the cell. In order to explain the difference of antileishmanial activity between ethanolic and aqueous extracts, anthocyanins amount was determined by spectrophotometry. It was found that the ethanolic extract is richer in anthocyanins than the aqueous one which can explain the higher antileishmanial activity of the ethanolic extract.

Photocatalytic degradation of the Acid Blue 113 textile azo dye in aqueous suspensions of four commercialized TiO(2) samples.

The apparent first-order rate constant, k(app), of the Acid Blue 113 textile azo dye photocatalytic disappearance in aqueous suspensions of 4 commercialized TiO(2) samples (50 m(2) g(-1)-Degussa P25; 54 m(2) g(-1)-Millennium Chemicals PC50; 250-270 m(2) g(-1)-Sachtleben Chemie Hombikat UV100; 320 m(2) g(-1)-Ishihara ST01) was determined from the decrease in the calibrated 566 nm-absorbance of the supernatant. Under the conditions used (1 liter-batch reactor; water-filtered irradiation from a Philips HPK 125-W high-pressure mercury lamp; [TiO(2)] = 1 g/L; [dye] = 70 mg/L), the k(app) ranking was: UV100 > PC50 > P25 > ST01. The corresponding maximal difference in k(app) was roughly equivalent to that caused by adding an optimal dose of H(2)O(2) to the P25 suspension. Taking into account the dye adsorbed amount, q(ads), in the dark, it is deduced that the recombination rate k(r) of photogenerated charges was higher for poorly crystallized TiO(2) samples, as expected; additionally, a low content of impurities is suggested to be at the origin of the low k(r) of UV100 relative to ST01. It is also argued that differences in the values of q(ads) divided by the surface area, S, was less due to pores inaccessible to the dye than to thicker layers of surface tightly bound water for the samples with high S. A FTIR study showed that the dye weakly interacted with TiO(2) and, however, remained the dominant adsorbed species during the degradation. This latter conclusion was in accord with the fact that the dye initial disappearance rates -- directly measured or calculated from k(app) -- were almost equal, indicating that the intermediate products of degradation did not significantly compete with the remaining dye for active species.