p. 1

before centrifugation after centrifugation corning corning sediments supernatant pellet

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p. 2

step 5 results of our experiments results from the spectroscopy absorbance versus wavelength nm up water 2h up water 1 night quan y of carbon released in 50ml of water a er 1 night of s u p water 1 night we made complementary experiments and we conclude that about 1 of the imprisoned carbon of the sediments is released into the water it s important to know that we measured the dissolved carbon because it was the easiest experiment to do but we also know that the other elements heavy metals behave almost the same way accordind to protee reseachers c released in the water c stayed in the sediment results from dissolved carbon 40 35 30 25 20 15 10 5 0 up water salty water ph6 salty water ph8 salty water ph10 initial supernatant concen mg.l-1 of di erent in dissolved carbon 1h 1 night 0/10 years conclusion time is a very important factor the longer sediments stay in water the more pollutants they free the sediments poten l of releasing is very important because to eliminate all the carbon present in the sediment we should repeat the experiment more than 100 example of the lead in the lazaret bay 1 released in 1 night means a concentra 77 higher than the maximum concentra allowed for aquafarming discussion and per for a clean dredging ves our awareness campaign the problem of the sediments is not well known by the people the inhabitants do not know the reason why the renova on of the harbour has been delayed in order to reply to this we made a conference in la seyne we appeared in newspapers var ma n and le seynois distributed into all the post-boxes of the town and printed in 35 000 exemplaries we published a gaze e to explain with simple words the problem of the sediments it can be found in all public places in la seyne laseyne.info a local media broadcast our project by making three movies published on the most visited website in la seyne finally we created a web site and a facebook group where we publish all our it allows exchange between us and all the curious who want to know more about our project cartochim and the bay contract contrat de baie in partnership with the navy and the laboratory protee of the university of toulon for the inventory of the bay needs by making corings and by mapping the di erent concentra di erent chemical species measures adapted to the roadstead of toulon environmental prot previsions of the dredging for the arrival of new frigates in 2013 need to win in bathymetry what do the dredged sediments become it is expensive to burry the heavily polluted sediments in a type 1 dump 1300 euros per ton but we could also give the sediments to the pla orm of research and treatment sedimed between la seyne and toulon there the sediments will be treated experimentally in order to ways of valorisa on or to make them less toxic this is why they need toxic dredged sediments to achieve scale tests ways of valorisa the sand can be used for road pr n of concrete or bailou or beaches the polluted part o he sediments can enter into the composi on o ndustrial cement because it contains aluminium silica and iron which then become very useful example of a clean dredging the geote our the chela for a clean dredging membrane the sediments are isolated and the pollutants cannot be released anymore in the water the sediments are pumped towards a waste container through an opening in the geotex the wasted waters are pumped towards a system of treatment there are resins which are chemically re ve capable of capturing heavy metals contained in the remobiliza on of sediments and of preven pollutants this is possible thanks to the a ni es between the components of the resin and the pollutants for example clays bind with heavy metals and charcoal with the organic contaminants a we propose to adapt a geote e by con resin between 2 layers of membrane this chela already exists for road engineering but not in there would be no the seawater with our resin problem to take the geotex e and the chela out of the water per ves there is informa about us and our project on the town hall s web site and on the rectorship web site we are very proud because thanks to our project the president of the bay contract has agreed that ate in the monitoring of the rst we dredging and the analysis next november next year we will take part in the wold water forum in marseille this awareness campaign permi ed us to broadcast our project inform the people and maybe for the youngest to encourage scien voca ons.

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