Italy 2006

Resource-conserving water treatment

In order to protect the valuable resource that is water, H+E and Alstom Power AG jointly developed a ZLD concept for power plants in areas with low precipitation.

In 2006, H+E installed a boiler feed water treatment plant for the 800-megawatt Gissi Abruzzo Energia power plant in southern Italy. The challenge was to adapt everything to the arid region. This is because power plants in areas with low precipitation cannot use well water or river water without surface water. This is needed for the production of drinking water and for irrigation. Often, however, process water is available from a waste water treatment plant that feeds from a local sewage treatment plant. At this site, receiving water for the discharge of treated waste water was also lacking, which further increased the challenge in identifying the solution. This is why H+E and Alstom Power AG jointly developed a zero liquid discharge concept.

A waste-water-free solution

Due to its special design, the plant supplies the boiler feed water in accordance with the VGB M 407 G regulation without any problems. The zero liquid discharge solution was also required because the treated waste water could not be discharged on site. Together with Alstom Power AG, H+E therefore designed a central, waste-water-free treatment plant, which also handles additional waste water streams from the power plant, for example from desludging.

Complete pollutant disposal

The central water treatment plant combines a pre-treatment by flocculation and a sewage treatment plant, a multi-layer filter and ultrafiltration with waste water treatment by reverse osmosis, batch neutralisation, evaporation crystallisation and sludge treatment. Finally, all waste is bound in the form of solids. The selected process combination therefore meets the highest requirements for waste-water-free disposal of harmful substances.

Facts & Figures

  • Compact design with a space saving of 15%
  • Reduction of energy demand by 20%
  • Short assembly time due to high degree of prefabrication
  • Combination with other process technologies possible