The eletrochemical and espectroelectrochemical behavior of the montmorilonita methylene-blue system (MM-AM)/ AMsolution have been investigated using cyclic volta mmetry and transient (I x t) techniques on modified ITO glass electrodes by film of composite (MM-AM) mechanically deposited. These films were prepared by three way: 1- in the absence of surfactant CTACl (cetyltrimethyl-ammonuim chloride); 2- with incorporation of CTACl into the interlayer region; and 3- in the presence of CTACl, however, not incorporated into the interlayer region. The spectroelectrochemistry technique was used for characterization and study of the formed films. The experimental results allowed assumptions as follows: 1- films prepared with AM previous incorporated into interlayer region supply a more efficient electrochemistry answer with the appearance of a couple of well defined peaks; 2-CTACl, in general, allows to obtain mechanically stable films; 3- when CTACl is previously included into interlayer region it doesn’t exist intercalated protonated specie, AMH+; 4- when protonated specie is absent the composite doesn’t shows electrochromic behavior.

Ethanol is an alternative fuel produced from sugarcane and economically very important for São Paulo state and Brazil. Vinasse, which has been traditionally distributed on the agricultural soil as an organic fertilizer, is the main residue of the ethanol production. Its dosage has been annually rationed in function of the potassium balance for reuse in agriculture. The vinasse potassium for ferti-irrigation can fully substitute potassium from mineral sources, but its transport is economically unviable from a determined distance. In this context, the paper presents the dehydration of sugarcane vinasse using a reverse osmosis technology to reduce the cost of transport until the sugarcane tillage. The main contributions are the reduction in the water content (concentration) and increase in the solid and the potassium content (13.8%). The study showed a payback value of 5.49 years.