Electro-Oxidation-Plasma Treatment for Azo Dye Carmoisine (Acid Red 14) in an Aqueous Solution.

Currently, azo dye Carmoisine is an additive that is widely used in the food processing industry sector. However, limited biodegradability in the environment has become a major concern regarding the removal of azo dye. In this study, the degradation of azo dye Carmoisine (acid red 14) in an aqueous solution was studied by using a sequenced process of electro-oxidation-plasma at atmospheric pressure (EO-PAP). Both the efficiency and effectiveness of the process were compared individually. To ascertain the behavior of azo dye Carmoisine over the degradation process, the variations in its physical characteristics were analyzed with a voltage-current relationship, optical emission spectra (OES) and temperature. On the other hand, chemical variables were analyzed by finding out pH, electrical conductivity, absorbance (UV/VIS Spectrophotometry), chemical oxygen demand (COD), cyclic voltammetry (CV), energy consumption and cost. The sequenced process (EO-PAP) increased degradation efficiency, reaching 100% for azo dye Carmoisine (acid red 14) in 60 min. It was observed that the introduction of small quantities of iron metal ions (Fe2+/Fe3+) as catalysts into the plasma process and the hydrogen peroxide formed in plasma electrical discharge led to the formation of larger amounts of hydroxyl radicals, thus promoting a better performance in the degradation of azo dye. This sequenced process increased the decolorization process.

Nerve fibers in ovarian endometriomas.

Ovarian endometriomas (n = 29) were innervated by mainly sympathetic and sensory fibers. These fibers may be involved in the generation of pain symptoms.

Removal of chromium and toxic ions present in mine drainage by Ectodermis of Opuntia.

This work presents conditions for hexavalent and trivalent chromium removal from aqueous solutions using natural, protonated and thermally treated Ectodermis of Opuntia. A removal of 77% of Cr(VI) and 99% of Cr(III) can be achieved. The sorbent material is characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, infrared spectroscopy, thermogravimetric analysis, before and after the contact with the chromium containing aqueous media. The results obtained from the characterization techniques indicate that the metal ion remains on the surface of the sorbent material. The percentage removal is found to depend on the initial chromium concentration and pH. The Cr(VI) and Cr(III) uptake process is maximum at pH 4, using 0.1g of sorbent per liter of aqueous solution. The natural Ectodermis of Opuntia showed a chromium adsorption capacity that was adequately described by the Langmuir adsorption isotherm. Finally, an actual mine drainage sample that contained Cd, Cr, Cu, Fe Zn, Ni and Pb was tested under optimal conditions for chromium removal and Ectodermis of Opuntia was found to be a suitable sorbent material. The use of this waste material for the treatment of metal-containing aqueous solutions as well as mine drainage is effective and economical.