T5- CLEAN-UP SYSTEM FOR DOMESTIC WATER USE
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S. Becerra
Principal Investigators : A. Ter Hal (IRMCP), L. Delmas (DEL)
Persons involved : L. Maurice, S. Becerra (GET), H. Budzinski, M.H. Devier (EPOC)
Objectives : Development and production of a system to purify water from PAHs for domestic use
Methods : development of an organogel material that specifically traps dissolved PAHs in water. The organogel material will be prepared using local resources (as palm oil and sugar)
Deliverables :a prototype (this project is in correlation with the GELUCS project submitted at the AO ANR ECO-TS in February 2013 by the team IMRCP (PI), EPOC and GET)
Risks :although a new material that is easy to prepare and to use with reduced fabrication costs, this material must first be tested and validated under laboratory conditions before being evaluated under real conditions.
« Hydrosafe » is the name given to the organogel material. The purpose of this material is to remove polycyclic aromatic derivatives from water for domestic use. The prefix « Hydro » for hydrocarbon and water and the suffix « safe » mean that after purification, the water will be safer for human use. So far, no systems have been described with the same characteristics. The future applications of this material are numerous (from potable water to decontamination of water bodies impacted by oil-activities).
T5.1.Development and production of a porous organogel material specific to organic and toxic molecules (IRMCP- DEL)
The criteria for selection of the constituents of the organogel materials are the following: they should be made from local and edible vegetable oils, the organogelator should also be edible (like carnauba wax, for example) and preferably from local resources. The porosity in the materials will be introduced by a leaching method through the use of sugar or salt crystals. During the step of elaboration of the material, it will be important to adjust the mechanical strength of the organogel (development of the mould from sugar or salt: grain size, mould size). The organogel materials are characterised by sol-gel and gel-sol phase diagrams, by elastic modules and by Scanning Electron Microscopy.
T5.2. Evaluation of the capacity of the organogel material to trap PAHs in aqueous phase (DEL-EPOC)
Four molecules will be selected among the list of the sixteen priority PAHs established by the US-EPA: naphthalene, anthracene, phenanthrene, benzo(a)pyrene. Each molecule will be first studied independently. Aqueous solution of the model compounds at sub-micromolar concentrations will be prepared for absorption by the porous organogel materials. The model compound decay will be monitored by HPLC and fluorescence detection or by GC-MS. The uptake kinetics will be then established. The equilibrium constant will be calculated for each molecule, together with the time necessary to reach equilibrium. The first tests will be undertaken with deionised water, and the second round of testing will use water with the same characteristics as that used by the local population (pH, conductivity, natural organic matter content, etc.). The laboratory tests will be undertaken under conditions similar to the storage conditions of water in the everyday life of the population (size of the container, temperature, time of storage). There will be an investigation of the compounds that could eventually leach from the material. We will also investigate a possible bacterial development on the materials. After use, the material can be recycled or destroyed. Calcination or composting is under consideration.
T5.3. Tests and in situ validation with volunteer families (GET- IRMCP-EPOC)
Like every innovation, Hydrosafe must induce change, should help to reduce the human exposure. Under the present circumstances, the goal is to bring a significant improvement in the daily life conditions of the families involved and to reduce risk by exposure to hydrocarbon derivatives in drinking water. In order to conceive, produce and validate Hydrosafe, efforts will be made to take into consideration the sociological conditions leading to a technological innovation from the earliest stage of the invention to the everyday life uses of the object, as evidenced by Rogers (1995). The advantages of the use of Hydrosafe must be clearly perceptible and it must be compatible with the existing values, past experiences and social habits of its users. The product must be easy to use and to understand. Furthermore, the people that will test the system will also help to develop confidence in the new product. Finally, considering Hydrosafe rapidity in trapping organic pollutants and the easy handling of the product, it is anticipated that volunteers’ families will easily and clearly see the results and willingly adopt its everyday use.