Projects

Topic 1: Drinking water quality improvement in Africa: the WATERSPOUTT Project (Water – Sustainable Point-Of-Use Treatment Technologies)

General Area(s): Chemistry, Microbiology, Water quality

Research Background:

The WHO and UNICEF estimate that nearly 750 million people around the world – mostly the poor and marginalized – remain without sustainable access to safe drinking water and if current trends continue, in 2015, 547 million people will remain without access to “improved” water sources (piped water, public tap, borehole, protected dug well, protected spring, rainwater).

The work proposed will develop a range of sustainable solar disinfection (SODIS) technologies that will provide affordable access to safe drinking water to remote and vulnerable communities throughout Sub-Saharan Africa and other resource-poor countries.

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Objective:

The main objective of the master work will predict SODIS inactivation as a function of the following parameters: physical properties, chemical parameters, natural and engineered enhancements of the process. These will be evaluated by their impact on microbiological and chemical targets.

Methodology:

  1. Systematic assessment of the contribution of the various physico-chemical parameters involved in the inactivation mechanism (i.e. iron, natural organic matter).
  2. Achieve the (chemical) enhancement of SODIS by applying the homogeneous or heterogeneous Fenton process.
  3. The extension of SODIS against multiple microbial and chemical targets (Bacteria, Viruses, organic pollutants).

To illustrate these aspects, deionized water or in some case (real water) will be spiked with microorganisms, at laboratory scale in Pyrex or PET bottle reactors containing the microorganism suspension (approximately 106 CFU ml-1). The photo-Fenton reaction is started by addition of low concentration of iron salts (FeSO4, FeCl3 or iron oxides) and H2O2 under Simulated solar light (Suntest), and various types of natural organic matter (NOM) will be evaluated on their photochemical influence.

Finally, as surface waters in Africa are often contaminated with pesticides, drugs and other human originated organic contaminants, the efficiency of the process against such compounds will be investigated.

Examples of MSc/PhD theses (in similar context):

Cristina Ruales-Lonfat, EPFL PhD Thesis (2015) «Iron oxides and iron citrate as new photo-catalysts in solar inactivation of Escherichia Coli in water: Mechanistic aspects».

Juliette Ndounla, EPFL PhD Thesis (2013) «Disinfection of Drinking Water by Helio-photocatalytic Process in Sahelian Zone: Chemical, Physical and Technological Aspects».

Chevalley Yannick, EPFL MSc thesis (2012) «Bacterial inactivation in real water via photo-Fenton treatment at near-neutral pH in solar CPC reactor».

Dorothea Spuhler, EPFL MSc thesis (2009) «The influence of Fe (II), Fe (III) and the photo-Fenton reagent on Solar Water Disinfection. Basic Assessment at Laboratory Scale».

Frédéric Sciacca, EPFL MSc thesis (2009) «Solar disinfection of surface water in the Sahel-The case of the photo-Fenton»


Topic 2: Hospital wastewater treatment in Ivory Coast and Colombia by Advanced Oxidation Processes

General Area(s): Chemistry, Microbiology, Water quality, AOPs

Research Background:

Water consumption is essential for life and it also plays an important role in the development of populations where the main economic activities are based in water supply and quality. However, the quality of life of African and some Latin American populations is being considerably harmed due to the increase of diseases that rise mortality rates and to the decrease of key species in the trophic chain. This situation is caused by insufficient, inadequate or inexistent water treatment plants in both urban and hospital effluent sources.

In Côte d’Ivoire and in the pacific coast of Colombia, the hospital liquid wastes containing pharmaceuticals micropollutants, detergents, antiseptics, etc., which are directly discharged in surface waters or simply poured in wells drilled, have brought the people in a high social and economic risk because surface waters hold a significantly fraction of all economic activities. Moreover, poor population realizes some artisanal activities like fishing in surface waters or ground waters, where the emergent contaminants are leaked from wells drilled, are frequently used as a source of drinking water.

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Objective:

The global objective of the work is to develop relevant, efficient and sustainable techniques based on Advanced Oxidation Processes (AOPs) for the treatment of emergent organic and microbiological pollutants in the hospital wastewaters in Ivory Coast, the pacific region of Colombia and Switzerland.

Methodology:

To attain the aims of the project the following methodology will be adopted:

  • Assessment of the global composition and biodegradability of the hospital wastewaters.
  • Realization of a systematic work using the proposed AOPs for the treatment of synthetic hospital wastewaters in order to:
  • Optimize and evaluate the effect of the most relevant physico-chemical parameters.
  • Identify the main reactive species responsible for the degradation and study the mechanism of pollutant transformation.
  • Determine the degradation extend (total mineralization or transformation to biodegradable and non-toxic by-products).
  • To test the best optimized technique for the treatment of real wastewaters at laboratory scale.
  • To build a pilot plant for demonstration in some of the target hospitals.
  • Dissemination of project result in both international and local scientific events.

In terms of targets, hospital derived compounds (drugs, disinfectants etc.) as well as a range of microorganisms (bacteria, viruses, yeasts) will be subjected to treatment to determine the efficiency of the selected AOPs.

Example of MSc/PhD Theses:

Stefanos Giannakis, EPFL PhD Thesis (2016, in progress), Advanced Oxidation Processes: critical issues in organic and microbiological pollutants elimination

Stefanos Papoutsakis, EPFL PhD Thesis, 2015, “Enhancing the photo-Fenton treatment of contaminated water by use of ultrasound and iron-complexing agents”.

Franco Alejandro Gamarra,Vives, EPFL MSc Thesis, 2015, “Impact of Advanced Oxidation Processes on micropollutants contained in municipal wastewater previously treated by three different conventional secondary treatment methods at the WWTP of Vidy, Lausanne”

Idriss Hendaoui, EPFL MSc Thesis, 2015, “Treatment of New Pharmaceutically Active Compounds by Advanced Oxidation Processes: Degradation of Venlafaxine”

Margaux Voumard, EPFL MSc Thesis 2015, “Effect of the simultaneous presence of viruses and their bacterial host during solar disinfection of wastewater and the post-irradiation period”

Samuel Watts, EPFL MSc Thesis 2015, “Effect of light-assisted AOPs on antibiotic resistant bacteria: Mechanistic aspects”

Siting Liu, EPFL MSc Thesis 2015, “Virus inactivation by near-neutral photo-Fenton in wastewater: influence of light intensity and Fenton reagents concentration”

Simon Schindelholz, EPFL MSc Thesis 2014, “Abatement of hospital-generated pollutants by advanced oxidation processes: iodinated X-ray media treatment in urine”

David Muzard, EPFL MSc Thesis, 2014, “Study of the impact of the Photo-Fenton system and its components on the inactivation of E. coli in water”