The SusWater project
Nowadays, the contamination of water resources coupled with the increased food demand is becoming a key issue. In fact, pollutants and micropollutants are conveyed to the environment by multiple routes and targeted actions to treat contaminated water are required.
Concerning water, monitoring the quality of the water and its toxicological load is mandatory to guarantee the consumption of pure water to citizens; besides, we need to expand access to pure water by planning actions able to treat contaminated water using environmentally sustainable technologies with the final aim to guarantee a low cost and microbiologically safe water. Concerning food demand, aquaculture is the fastest growing food producing industry globally. Fish farms placed along water resources gradually replace pond water with freshwater that may be unfortunately contaminated with potentially toxic elements (PTEs) and contaminants of emerging concern (CECs) originating from anthropogenic and natural sources thus becoming a risk for public health, as well as the leading cause of fish death and financial losses in the market. Because of the nutritional importance of fish and public health concerns, there is a need to assess the health impact of CECs and PTEs in farmed fish for human consumption but also in their food, water and sediment collected in farms.
Additionally, one of the critical and known issues of recirculated aquaculture production is the microbiological generation of lipophilic taste and odour compounds, in particular geosmin and 2-methylisoborneol (MIB). These components accumulate in the fish causing bad taste rendering it unfit for consumption, thus leading to high economic losses for the aquaculture industry due to the need to off-flavor the fish in purge tanks. In this way, geosmin and MIB are transferred from fish tissue to water until they reach equilibrium through a relatively costly method, since, to ensure their proper removal, large quantities of pure water are required.
Aim and Action
This project aims to face the complex challenge of the production of safe and clean water by applying different levels of action, which include the synthesis of green materials for the removal of pollutants, the development of enhanced water treatment technologies, the implementation of effective legal tools against water pollution and the correct management of the present water treatment facilities. Two main goals will be achieved by applying an integrated approach. On one side, the development of new tools useful for eliminating pollutants. On the other side, quality of water will be constantly assessed.
In particular, SusWater will assess the quality of water in a pilot WWTP (in URJC, Spain) and in two aquaculture sites (Italy, Thailand) by monitoring CECs and PTEs in influents, effluents and post-treated waters and by assessing the toxicity through the combination of different bioassays. The monitoring process will involve not only chemical and toxicological analysis performed by high-resolution techniques, but it will be combined with modelling processes aimed to fully assess the fate of pollutants.
Secondly, aquaculture discharge typically contains nutrients rich waste that requires treatment prior to release as, if discharged untreated, it can lead to pollution of surface waters. Among the physical removal strategies, we will use hydrogels, as they can show high adsorption capacity, fast adsorption kinetics, good reusability and low cost. SusWater’s development of photocatalysts and hybrid materials properly designed to absorb visible light will allow achieving abiotic transformation of CECs, PTEs and off-flavors by exploiting the use of natural sunlight.
Furthermore, the biological approaches offer a potential alternative to chemical and physical based techniques. In SusWater, fungi will be used to eliminate contaminant of emerging concern (CECs), with particular focus on antibiotics and some lipophilic compounds responsible of unpleasant taste on fish. On the other hand, potentially toxic elements (PTEs) such as dissolved As, Hg, Pb or Cd species will be captured by exploiting the use of iron, adsorbents derived from biomass and inorganic oxides and photocatalysts jointly linked to strengthen their efficiency.
The project will be developed on the basis of the following workpackages: