The fabrication of a fully bio-sourced adsorbent of Cd(Ⅱ)by covalent immobilization of quinine on cellulose paper is described.The double bond of commercially available quinine was converted to a terminal alkyne function which was reacted with cellulose paper,chemically modified with azide functions,through a 1,3-dipolar cycloaddition,leading to Cell-Quin.The adsorption efficiency of Cell-Quin was investigated to determine the optimal pH,contact time and dose of adsorbent,ultimately leading to high levels of removal.The mechanism of adsorption of Cell-Quin was deeply rationalized through kinetic experiments and isotherm modeling.We also showed that Cell-Quin could adsorb other heavy metals such as Cu(Ⅱ),Pb(Ⅱ),Ni(Ⅱ)and Zn(Ⅱ). 相似文献
Journal of Material Cycles and Waste Management - This study contributes towards showing the potential end-of-life application of common wastes namely: Waste Toner powder (WTP) and African star... 相似文献
The largest beach replenishment project ever in France was completed in February 2014 in Dunkirk on the coast of northern France. A volume of 1.5 × 106 m3 of sand extracted from a navigation channel was placed on the beach to build up a 150 to 300 m wide supratidal platform in front of a dike, called « Digue des Alliés », which protects several residential districts of Dunkirk from marine flooding. High resolution topographic surveys were carried out during 2½ years to monitor beach morphological changes, completed by a hydrodynamic field experiment conducted in February 2016. Approximately ?138,200 m3 of sand, corresponding to 9.2% of the initial nourishment volume, were eroded over the nourishment area in about 2 years. An obvious decrease in erosion eastward with a shift from erosion to accumulation was observed, suggesting an eastward redistribution of sand. This longshore sand drift is beneficial for the eastward beach of Malo-les-Bains where most of the recreational activities are concentrated. Hydrodynamic measurements showed that waves and wave-induced currents play a major role on the longshore sand redistribution compared to tidal flows. Strong relationships were observed between cumulative offshore wave power and beach volume change during distinct beach survey periods (R2 = 0.79 to 0.87), with more significant correlations for northerly waves. A slight decrease in erosion during the second year compared to the first year after nourishment suggests that the loss of sand should decrease after an initial phase of rapid readjustment of the beach shape towards equilibrium. 相似文献
Environment Systems and Decisions - Globally we are experiencing a decline in aggregate natural capital. Many primary industries and enterprises are highly dependent on renewable and non-renewable... 相似文献
Imprinting Disorders (ImpDis) are a group of congenital syndromes associated with up to four different types of molecular disturbances affecting the monoallelic and parent-of-origin specific expression of genomically imprinted genes. Though each ImpDis is characterized by aberrations at a distinct genetic site and a specific set of postnatal clinical signs, there is a broad overlap between several of them. In particular, the prenatal features of ImpDis are non-specific. Therefore, the decision on the appropriate molecular testing strategy is difficult. A further molecular characteristic of ImpDis is (epi)genetic mosaicism, which makes prenatal testing for ImpDis challenging. Accordingly, sampling and diagnostic workup has to consider the methodological limitations. Furthermore, the prediction of the clinical outcome of a pregnancy can be difficult. False-negative results can occur, and therefore fetal imaging should be the diagnostic tool on which decisions on the management of the pregnancy should be based. In summary, the decision for molecular prenatal testing for ImpDis should be based on close exchanges between clinicians, geneticists, and the families before the initiation of the test. These discussions should weigh the chances and challenges of the prenatal test, with focus on the need of the family. 相似文献
Environmental Chemistry Letters - The global production of biogas has increased threefold during the last decade to partly replace fossil fuels, yet biogas production by anaerobic digestion... 相似文献
For the prediction of metal mixture ecotoxicity, the BLM approach is promising since it evaluates the amount of metals accumulated on the biotic ligand on the basis of water chemistry, i.e., species (major cations) competing with metals, and related toxicity. Based on previous work by Farley et al. (2015) (MMME research project), this study aimed at modeling toxicity of Cd:Cu mixtures (0:1 - 1:1 - 1:0 - 1:2 - 1:3 - 2:1 - 3:1 - 4:1 - 5:1 - 6:1) to the crustacean Daphnia magna(48-h immobilization tests) and the microalga Pseudokirchneriella subcapitata (72-h growth inhibition tests). The 2012 version of the USGS model was chosen, assuming additivity of effects and accumulation of metals on a single site. The assumption that EDTA could contribute to toxicity through metals complexing was also tested, and potential effects due to reduction of ions Ca2+ absorption by metals were considered. Modeling started with parameter values of Farley et al. (2015) and some of these parameters were adjusted to fit modeled data on observed data. The results show that toxicity can be correctly predicted for the microalgae and that the hypothesis of additivity is verified. For daphnids, the prediction was roughly correct, but taking into account CuEDTA led to more realistic parameter values close to that reported by Farley et al. (2015). However, It seems that, for daphnids responses, metals interact either antagonistically or synergistically depending on the Cu:Cd ratio. Furthermore, synergy could not be explained by additional effects linked to a reduction of Ca absorption since this reduction, mainly due to Cd, increased inversely to synergy. Finally, the USGS model applied to our data was able to predict Cu:Cd mixture toxicity to microalgae and daphnids, giving rise to estimated EC50s roughly reflecting EC50s calculated from observed toxicity.
Environmental Science and Pollution Research - Laboratory testing with spiked sediments with organic contaminants is a valuable tool for ecotoxicologists to study specific processes such as effects... 相似文献