Avec leur statut original, quels rôles pour les sociétés d'aménagement régional dans les politiques de l'eau et de l’irrigation ?

Les sociétés d’aménagement régional (SAR) opérateurs régionaux de la gestion de l’eau avec un mandat d’aménagement du territoire ont un statut original de sociétés commerciales. Elles jouent un rôle majeur dans la réalisation des investissements nécessaires à l’irrigation dans le Sud de la France. Une interview de trois cadres de ces sociétés permet de cerner comment elles peuvent jouer ce rôle. La relation avec les irrigants se fait par des contrats de droit privé impliquant généralement un comptage des quantités d’eau distribuée et une attention particulière au prix de l’eau. La vente d’eau à différents usagers agricole, urbain ou industriel permet d’équilibrer les comptes. Ces sociétés apportant à l’État la garantie d’organisations structurées, la répartition de l’eau, la création de ressource avant l’équipement des exploitations irrigantes, le conseil d’État recommande de leur donner plus de poids. / Regional development companies (SAR), regional organizations of water management with a role of regional planning and development have, in France, an original status of corporations. They play a major role in making the necessary investments in irrigation in the South of France. An interview with three managers of these companies can identify how they can play this role. Relationship with irrigators is done by private contracts generally involving water measurement and special attention to water price. The sale of water to different users agricultural, urban or industrial balances the accounts. As these companies bring to the state the guaranty of structured organizations, balanced distribution of water, creating resource before farm equipment, the State Council recommends to give them more weight

Mineralogical attenuation for metallic remediation in a passive system for mine water treatment

Passive systems with constructed wetlands have been consistently used to treat mine water from abandoned mines. Long-term and cost-effective remediation is a crucial expectation for these water treatment facilities. To achieve that, a complex chain of physical, chemical, biological, and mineralogical mechanisms for pollutants removal must be designed to simulate natural attenuation processes. This paper aims to present geochemical and mineralogical data obtained in a recently constructed passive system (from an abandoned mine, Jales, Northern Portugal). It shows the role of different solid materials in the retention of metals and arsenic, observed during the start-up period of the treatment plant. The mineralogical study focused on two types of materials: (1) the ochre-precipitates, formed as waste products from the neutralization process, and (2) the fine-grained minerals contained in the soil of the wetlands. The ochre-precipitates demonstrated to be poorly ordered iron-rich material, which gave rise to hematite upon artificial heating. The heating experiments also provided mineralogical evidence for the presence of an associated amorphous arsenic-rich compound. Chemical analysis on the freshly ochre-precipitates revealed high concentrations of arsenic (51,867 ppm) and metals, such as zinc (1,213 ppm) and manganese (821 ppm), indicating strong enrichment factors relative to the water from which they precipitate. Mineralogical data obtained in the soil of the wetlands indicate that chlorite, illite, chlorite–vermiculite and mica–vermiculite mixedlayers, vermiculite, kaolinite and goethite are concentrated in the fine-grained fractions (<20 and <2 μm). The chemical analyses show that high levels of arsenic (up to 3%) and metals are also retained in these fractions, which may be enhanced by the low degree of order of the clay minerals as suggested by an XRD study. The obtained results suggest that, although the treatment plant has been receiving water only since 2006, future performance will be strongly dependent on these identified mineralogical pollutant hosts.Fundação para a Ciência e a Tecnologia (FCT

Pressurised electro-osmotic dewatering of activated and anaerobically digested sludges: Electrical variables analysis

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