RESALT (2020–Present)

RESALT aims to regenerate treated water for reuse in the tanning industry, promoting sector sustainability.

The RESALT project, led by IDR and Tradebe, seeks to regenerate water from the treatment plant's wastewater to reuse it in Igualada's tanning industry, with the goal of reducing water consumption and minimizing salt used in the process. This project is unique because it generates two final flows: clean water (osmosed) and salty water (brine), with the latter being a reject that can also be reused in tanneries, thus contributing to total resource reuse. The leather industry, which consumes a lot of water, had already adopted various measures to reduce its consumption, but wanted to go further to be more sustainable.

The RESALT project aims to combat the effects of drought by regenerating treated water to be reused in the tanning industry, which allows reducing dependence on clean water from reservoirs and wells. In addition to generating regenerated clean water, the project also produces salty water, which can be reused in tannery processes, thus minimizing mineral salt consumption.

This approach contributes to closing the water cycle sustainably, promoting a more environmentally respectful sector. Through the circular economy, the project improves the sustainability of the leather industry and helps mitigate the effects of drought, with a positive impact on the environment and society. For all this, this project becomes an example of sustainability that can inspire other cities to implement similar solutions to face current water challenges.

The project began in 2020 with a first pilot that used various technologies such as a flotation system (DAF), ultrafiltration, nanofiltration and reverse osmosis. This pilot demonstrated the effectiveness of DAF technology to treat treatment plant water. Subsequently, a second pilot was developed, which allowed obtaining the two regenerated water flows, one clean and one salty.

In 2024, a semi-industrial ultrafiltration plant was put into operation to use regenerated water in industry processes and in the treatment plant itself. In the future, it is wanted to treat the treatment plant's output water through a 1000 m³/day plant to generate 50% of the water needed for Igualada's leather industry.