IDOUM

Reuse of treated wastewater is increasingly seen as one of the solutions to tackle the water scarcity problem and to limit the pollution load to surface water. Yet, using reclaimed water for non-potable purposes and particularly to irrigate food crops presents an exposure pathway for antibiotics and antibiotic resistant bacteria and genes (ARB&G) to enter the human food chain. Wastewater reuse is currently of particular concern as potential source of selective pressure that elevates the levels of antibiotic resistance in native bacteria. There are also growing concerns that environmental concentrations of antibiotics exert a selective pressure on clinically relevant bacteria. These acute strains call for a major shift towards a more localized management of the water cycle, pioneering low cost wastewater treatment technologies, and more efficient monitoring strategies based on a limited number of indicators that would facilitate the assessment of the anthropogenic impact on the water cycle. This project aims at: i) establishing monitoring strategies based on the data-derived prioritization of a set of indicator contaminants and pathogens for domestic wastewater, and ii) developing energy-efficient, cost-effective, and robust treatment systems for the decentralized production of treated wastewater mainly from domestic wastewater. Diagnostic indicators will be selected based on their regular occurrence, potential for leaching/mobility and toxicological relevance. The second major objective of this project is to design wastewater treatment technologies based on the combination of biological-based treatment systems using selected plants and microorganisms (e.g., fungi, endophytic bacteria and microalgae) and the use of low-cost engineered nanostructured materials for catalytically activation of oxidants (persulfate and hydrogen peroxide). These decentralized treatment systems using smart technologies will be tailored to remove key antibiotics and ARB&G. Thus, IDOUM project will help to protect our freshwater supply, reduce the risk of human exposure to toxic compounds and of antibioresistance spreading, and provide access to alternative sources of water.

WP1 Selection of chemical and microbial indicators

Task 1 Screening of antibiotics and ARB&G. A standardized analytical method based on an off-line SPE method followed by LC-MS/MS or LC-high resolution-MS will be implemented among partners for quantification and identification of trace concentration of antibiotics in raw wastewater and in reclaimed water. Partners will also develop harmonized methods to assess the abundance of ARB&G in wastewater relying both on culture-dependent and culture-independent methods (quantitative PCR).

Task 2 Assessing possible antibiotic resistance proliferation through wastewater reuse

Developed analytical methodologies will be applied to properly evaluate wastewater treatment technologies and to investigate the mobility/persistence

of antibiotics and ARB&G in reclaimed water in each of the participating countries. A priority list of antibiotics and ARB&G will be defined.

WP2 Development of biological-based treatment systems

Task 1 Phytoremediation with endophytic bacteria inoculation. First step will consist in the identification of endophytic microorganisms of Phragmites australis. Second step will include the bio-inoculation of ponds and/or constructed wetlands for bioremediation improvements of antibiotics and ARB&G

Task 2 Phycoremediation with specific algae species. First, specific selected algae will be evaluated for antibiotic and ARB&G removal. These latter will be released in sewage ponds to assess their capacity to multiply by effectively outcompeting resident non-productive species and by sequestrating the nutrients.

Task 3 Mycoremediation with specific Trichoderma sp. Different commercially available Trichoderma sp. strains will be cultivated under controlled conditions to evaluate their capacity to eliminate antibiotics and ARB&G. The best performing fungal species will be adapted in bioreactors for real domestic wastewater treatment assessment.

WP3 Development of nano-structured catalytic materials for oxidant activation

Task 1 nano-CuO assisted generation of sulfate radical. CuO nanoparticles will be anchored in clay mineral (e.g., bentonite). Clay composites will be granulated and tested for persulfate activation into sulfate radical. Filtration by nanoclay composites will be assessed for antibiotics and ARB&G removal.

Task 2 Modified iron minerals and iron mining residues for heterogeneous Fenton processes with H2O2. The iron materials will be prepared by coprecipitation method in the presence of different concentrations of modifying metals (Cu or Ce). Process efficiency will be evaluated by kinetic studies and by-products identification by LC-MS.

WP4 Technology integration and technology demonstration

Task 1 Technology demonstration. Feasibility and technical capability of the combined (biological + chemical) operation will be planned at several experimental sites. At the wastewater reuse platform for irrigation located in Murviel-lès-Montpellier, a mixed reactor will be specifically designed to treat secondary biological WWTP effluents and will be coupled to an AOP step involving CuO clay composite and persulfate working in a filtration mode. At the Helmholtz Institute in Munich, it is proposed to connect a series of middle-sized (10-50 m3) treatment basins to the original domestic wastewater effluent pipe. Each basin would represent a certain type of treatment option such as vertical surface, vertical subsurface and horizontal subsurface constructed wetlands and some AOPs tanks. At the Mossay Bay sanitation facilities (South Africa), sewage ponds will be inoculated by the specific selected algae and effluents will be passed through CuO filters before they will be used as food source for aquaculture species in final ponds. At the clinic hospital of Universidade Estadual de Campinas (UNICAMP), hospital effluents will be treated by a combination of anaerobic biological treatments with heterogeneous Fenton tanks using modified iron minerals.

Task 2 Technology benchmarking. Proposed technologies will be benchmarked against other treatment methods (for instance, UV-C or BRM) in terms of energy consumption (electric energy per order) and the cost of chemical addition (if required).

• Transition from traditional centralized energy-intensive water management practices towards satellite production of treated wastewater for its safe local reuse - avoiding large capital cost and reduced operation and maintenance – supporting local water recycling policies
• Depending on the project results, patent application and possibility of job creation for young researchers through spin-off companies
• IDOUM is expected to have an impact on environmental and public health by defining lists of priority contaminants in each participating country
• Knowing which contaminants and pathogens are regularly occurring in wastewater and solutions to eliminate them at source will contribute to UN Goal 6 “to ensure availability and sustainable management of water and sanitation for all”