Synthesis, interfacial and chelating properties of new sugar-based surfactants

NADÈGE FERLIN; ERIC GRAND; DIEGO GRASSI; CARLOS OJEDA; MARIANO CASTRO; ALICIA FERNANDEZCIRELLI; JOSÉ KOVENSKY

Paris, Francia

Congreso; 7th World Surfactants Congress (CESIO 2008); 2008

European Committee of Organic Surfactants and their Intermediates (CESIO)

Metals and heavy metals are nowadays considered as a problem of public health since they are very toxic and dangerous depending on their concentration. Although they can be of natural occurrence (volcano is one of the main natural sources of concentrated metals in the environment), pollution by metals and especially by heavy metals, results from human activities (ore extraction, mine wastes and oxidation of mineral sulphurs, metallurgy, domestic wastes, transports, agriculture, mud from refining station for water, hunting…). Their harmfulness is provided by their accumulation in the soils and water, then in plants and animals. Some of them are necessary to the organisms in small amounts (Ni, Cu, Zn…) while others are toxic (Hg, Pb…), even in small quantities. Remediation of polluted soils and water is a technological problem, and numerous technologies can be employed depending on the pollutant and the polluted material. Among the different treatments of the pollution, it exist biological treatments and chemical treatments. The most used biological treatment is phytoremediation which is the absorption of the metal by a plant organism because of its needs. A wide range of chemical treatments are possible. Some technologies to remove soil pollution are transfers from soil to water by solubilisation. This can be done by acidification and/or the use of a chelating agent like EDTA. To remove a metal from water, a precipitation can be effected after an oxidation or a pH change. Others technologies are floculation, cationic exchange, reverse osmosis with a membrane, electroremediation or flotation. The later methodology, flotation, eliminates metallic pollutants of an aqueous phase by addition of surfactants, after complexation of the metal by the surfactant, air is bubbled to make a foam rich in metallic particles which can be removed from water.