Point de vue du concessionnaire : gestion des sédiments du Rhône

Effects of a physico-chemical treatment of a dredged sediment on its ecotoxicity after discharge in laboratory gravel pit microcosms

“…Nitrate concentrations were close to 10 or 16 mg/L in all waters, with no significant change due to sediment addition. The immersion of treated sediment led to an increase of ions (K + , Na + , Mg 2+ , Ca 2+ , SO 4 2− , Cl − ) of surface and ground waters, corroborated by the observed increase of conductivity, whereas the raw Table 2 Evolution of groundwater quality (detectable metals) downstream LGPs following sediment addition ((): potability limits; DL: detection limit).…”

“…For the RS LGP, sampling of RS pore water was not possible due to clogging of the U-shape glass tube designed to collect water. For major ions, concentrations were highest for the treated sediment (TS) and the lacustrian sediment beneath, especially for Mg 2+ , Ca 2+ , Cl − and SO 4 2− , whereas moderate concentrations of RS lacustrian sediment indicate significant but moderate release of salts from RS.…”

“…In France, 2.5-3.5 millions of tons of sediments are annually dredged from rivers and canals [1][2][3][4]. Dredged sediments of navigation canals are often contaminated wastes which pose a threat for the environment when they are disposed in unsafe conditions.…”