VNT evaporator installed in ABC
ABC. The first newspaper to incorporate vacuum evaporation to treat sewage
ABC was the first Spanish newspaper to use vacuum evaporation technology for the in-companytreatment of wastewater from its printing processes. The efficiency of the technology makes it possible to obtain a final waste of the highest concentration, with which the costs of managing the resulting waste have been reduced to a minimum. The water treated by the evaporator is recycled for other uses.
This technology is being used in many industrial sectors. Vacuum evaporation is being implemented in the graphic arts sector due to the advantages it offers compared to other purification techniques, such as osmosis or ultrafiltration.
The wastewater generated by a newspaper such as ABC is mainly from the prepress devices (developer liquids) and from the rotary presses (the dampening water resulting from the washing of the ink on the printing plates).
At the end of the distillation process, the treated water is recycled for various uses (irrigation, sanitation, etc.) and the resulting concentrated waste is sent to an external manager.
The decisive factors in the decision were: the energy savings of working in vacuum conditions, the low conductivity of the resulting water – less than 300 microsiemens (legal maximum is 6,000) – and the resulting COD – between 600 and 800 ppm (legal maximum is 1,500). These values would have allowed the resulting water to be discharged within the law, but the company has opted for the “zero discharge” principle, whereby the treated water extracted from the evaporator is reused for cleaning tasks, such as washing the printing plates.
The cost-saving impact is twofold. Firstly, the drastic reduction in waste management costs, since it is concentrated to the maximum (concentrations above 90%). Secondly, the significant savings in water (more than 90 percent of the treated liquid is recovered).
If we look at it from a sustainability point of view, we save on such a valuable resource as water and we contribute to the first phase of waste concentration before its final treatment at the specialized waste manager.
