Project

AIGUANEIX is the first step towards equipping the northern Costa Brava with a system for producing water that will increase the region’s resilience in the event of new episodes of drought.

Purifying water to ensure its future supply

The AIGUANEIX project aims to address the challenge of supplying water by promoting a circular approach to 21 st century water management, in accordance with the United Nations’ Sustainable Development Goals.

Context / Background

The long drought suffered by Catalonia since 2021 has laid bare the country’s great dependency on surface water, particularly in the coastal municipalities. The Costa Brava is no exception, as the almost complete exhaustion of the water supply has raised the question of how to ensure the quantity, quality and continued supply of this resource while the climate emergency is ongoing.

The answer to this question is neither easy nor clear; however, the gravity of the situation means it is necessary to develop alternative solutions that are able to guarantee the availability of water in the future within the context of worsening climate change. Purified water has emerged as one such alternative, and it is to this end that the AIGUANEIX project is being put into practice.

Objectives

The main objective of the AIGUANEIX project is to produce purified water that complies, in a technologically efficient way, with the regulations governing the supply of water. To achieve this objective, the water produced must be submitted to the Agència de Salut Pública de Catalunya (Catalan Public Health Agency) and the Agència Catalana de l’Aigua (Catalan Water Agency) for analysis and evaluation.

By pursuing this objective, AIGUANEIX seeks to help replenish the aquifers that feed the water supply, improve resilience in the event of drought and create a circular water-production system that can be replicated in other areas within Catalonia.

Pilot
plant

Purified water is reclaimed water that has been subjected to additional and highly advanced treatment in order to make it suitable for replenishing the aquifers that supply communities. The processes involved in producing purified water are technically complex, and require the creation and operation of a pilot plant under controlled conditions.

Purification is achieved through six different processes: chloramination, ultrafiltration, reverse osmosis, advanced oxidation, microfiltration with activated carbon, and remineralisation.

Work
plan

The pilot plant will be operated on an experimental basis in line with a work plan drawn up by the project’s scientific director. This plan encompasses:

Setting the operational parameters for the different treatment processes.

Defining the analytical monitoring process to ensure that the quality of the water produced is classified correctly.

The operation of the different treatment processes that comprise the multiple barrier system implemented in the pilot plant.

The main objectives of the work plan are:

To verify that the water produced is of high quality and sufficiently safe to be injected into an aquifer for subsequent use as drinking water. The water quality criteria stipulated in Royal Decree 03/2023, along with other recognised and relevant criteria that apply to the use of reclaimed water for these purposes, will be taken into account.

To select working conditions that put each of the different technological barriers to the test, in order to thoroughly assess their capacity to remove contaminants.

To generate data that enable the creation of the documentation required to control the potential risks to water quality, whether by monitoring the water produced or by monitoring performance and the operational parameters for the individual barriers.

To achieve these general objectives, the project proposes to operate the pilot plant under a range of different working conditions:

Operation with the full treatment process.

Operation only with the reverse osmosis phase.

Operation with the full treatment process, but with increased flow in the ultrafiltration and reverse osmosis phases in order to enable increased water recovery.

Repeat the first condition with the full treatment process.

Divert part of the filtered water from the ultrafiltration phase to the inlet of the advanced oxidation process (AOP), so that the water at the AOP inlet is a mixture of water from the reverse osmosis and ultrafiltration phases.

Divert the filtered water from the ultrafiltration phase to the inlet of the granular activated carbon (GAC) phase, so that the water at the GAC inlet is an equal mixture of water from the AOP and the ultrafiltration phase.

Additionally, the following short-term tests will be carried out:

Assessment of the contact time with chloramines in the formation of disinfection by-products.

Addition of markers to the input water in order to determine the integrity of the membrane-based processes.