ZERO PLUS - Best Technologies applied to Non Ionic Degreases

The BREF on “Surface Treatment of Metals and Plastic Materials” does not establish any differences in the behavior of anionic and non-ionic aqueous degreases. As a consequence, the BATs proposed for separating emulsified oils, and, particularly, cross-flow filtration techniques, are not efficient when applied to non-ionic degreases. The Zero Plus Project proposes an alternative – and candidate to BAT – for these cases, consisting in the association of vacuum evaporation and electrocoagulation. Vacuum evaporation is used for the batch treatment of spent degrease bath volumes generated in time, whereas electrocoagulation is used for the continuous treatment of the drag-outs from the degrease bath that reach the aspersion rinse stage. As a result of this work, a significant reduction in effluent volumes produced and an almost total recovery of rinse waters have been achieved, with an insignificant volume of sludge and a very reduced volume of energetically valuable concentrated effluents as a tradeoff.