Extraction of Sm(III)and Nd(III) with N,N,N’,N’-tetrabutyl-3-oxy-diglycolamidefrom hydrochloric acid

The extraction behavior of Sm(III) and Nd(III) with N,N,N’,N’-tetrabutyl-3-oxa-diglycolamide (TBDGA) in 70% kerosene-30% n-octanol from hydrochloride acid wasstudied. The effect of hydrochloric acid concentration, extractant concentration,and temperature on the distribution of rare earth elementswas investigated. The extraction mechanism was established and the stoichiometry of the main extracted species was confirm to be SmCl3•2TBDGA and NdCl3•2TBDGA for Sm(III) and Nd(III), respectively. The extraction distribution ratio decreases with an increase in temperature, which demonstrates that the extraction reaction is exothermic. The IR spectra of the loaded organic phase and free extractant were recorded and discussed

Electric-field controle of the pH-dependent redox process of cytochrome c immobilized on gold electrode

The pH-dependent redox processes of cytochrome c (cyt c) immobilized on a gold electrode that was coated with a self-assembled monolayer (SAM) of mercaptounadecanoic acid (MUA) were studied by electrochemical methods combined with quartz crystal microbalance (QCM) and surface enhanced infrared absorption (SEIRA) spectroscopy. Variation of the solution pH in the range from 4.0 to 10.0 determines the surface charge of the SAM, for which an apparent p

A mosaic community of macrophytes for the ecological remediation of eutrophic shallow lakes

The restoration of macrophytes in eutrophic shallow lakes has been the focus of active research in the past decade. The approach of building up a mosaic community of macrophytes (MCMs) to improve water quality and remediate the ecosystems of lakes is proposed in this paper. Several species of floating, floating-leaved, and submerged macrophytes were introduced in experimental enclosures in eutrophic shallow lakes. These macrophytes were intercropped in small patches and formed mosaic communities of spatial and temporal combinations (spatial and seasonal mosaic patterns) in the lakes. Macrophytes can improve water transparency quickly and the MCM system can stabilize this clear water state over a long time in turbid eutrophic shallow lakes. The constructed MCM created heterogeneous habitats that are favourable for different macrophytes and for the growth and succession of other organisms, as well as for removing water pollutants. When the eutrophic water flowed through the MCM system at a retention time of 7 days, the removal efficiency rates of the MCM system for algae biomass, NH4+–N, TN, TP and PO43−–P were 58%, 66%, 60%, 72% and 80%, respectively