IDR launches a pilot plant to regenerate treated water and give it a second life

Within the horizon of zero waste in the tanning industry, and in a context in which the growing problem of water supply in Catalonia is a serious concern, the Igualada tanners' treatment plant, Igualadina de Depuració i Recuperació S.L. (IDR), is working on the introduction of a Water Regeneration Station (ERA).

The tanning industry, as a player in the circular economy, since it adds value to a waste product of the food sector in order to produce durable consumer goods that are useful to society, is very much aware that water is a scarce resource and that managing it well is a fundamental pillar of the sustainable use of natural resources.

The treatment plant of Igualadina de Depuració i Recuperació S.L. (IDR), one of the pioneering plants in Europe for the treatment of industrial wastewater, treats every day the water generated in the leather transformation process by the 28 tanning companies in Igualada that are members of Leather Cluster Barcelona, together with part of the urban water and water from other industries. IDR also contributes knowledge on good water management and water saving to the whole cluster.

This ambitious project to build a Water Regeneration Station (ERA) consists of treating the effluent from the IDR treatment plant (the water leaving the plant once already treated) in order to obtain a flow of osmosis-treated water (practically pure water) and another of salt water, both reusable by the tanning industry or for other purposes.

Water is a natural resource and an indispensable source of life, essential for improving living conditions, economic growth, environmental conservation and sustainable development. It is a finite and scarce resource, and the ever more evident effects of climate change are leading us towards a future in which saving water and using it more efficiently will be essential.

In this respect, the Catalan Water Agency (ACA) has for years been committed to the use of non-conventional resources in order to increase water security and availability. One of these is regenerated water, obtained by applying an additional treatment to water that has already been treated, using facilities known as tertiary treatments or Water Regeneration Stations (ERA). Through treatments such as reverse osmosis, ultrafiltration and nanofiltration, these tertiary facilities give the water a quality suitable for various uses.

One of the difficulties presented by water regeneration stations is the treatment of the salt fraction that comes out as reject. In IDR's case it is expected that this flow can be reused, since tanning companies need salt for their process.

Through these tertiary treatments, the ACA currently regenerates 39 hm3/year in Catalonia. With this project IDR plans to regenerate up to 0.5 hm3/year (almost 1.4 million litres a day) and has already taken the first step, with the launch of a pilot plant to regenerate treated water.

The pilot plant, now in operation, was designed by the Igualada-based company Waterologies, experts in technology and intelligent equipment for water treatment.

The plant has two phases. The first is a pre-treatment stage to prepare the water so that it can enter a membrane system, and the second consists of passing the water through different types of state-of-the-art membranes to separate the water from the salt and other elements present, in various stages such as nanofiltration and osmosis.

Over the course of a year, the automated pilot plant will generate 10 m3 of osmosis-treated water and 2 m3 of salt water a day. Different membrane options, their performance and all the auxiliary systems will be tested. The water obtained will be analysed at the A3 Leather Innovation Center UdL research and innovation centre in order to verify its quality and its suitability for the leather tanning process, and the water will then be supplied by tanker to various companies, which will assess how it behaves in their respective processes.

Leather Cluster Barcelona is an environment of competitive cooperation for promoting cross-cutting, transformative strategic projects with the aim of driving forward the ecosystem of the Catalan leather sector. The cluster is an accredited entity within the Catalonia Clusters programme and has the support of Acció.