Amino-Thiol Bifunctional Polysilsesquioxane/Carbon Nanotubes Magnetic Composites as Adsorbents for Hg(II) Removal

Amino-thiol bifunctional polysilsesquioxane/carbon nanotubes (PSQ/CNTs) magnetic composites were prepared by sol-gel method with two types of functional siloxanes coating on carboxyl CNTs simultaneously. The composites were served as efficient adsorbents for removing Hg(II) in aqueous solution and the adsorption properties were investigated systematically. The optimal pH of bifunctional composites for Hg(II) removal is at pH 4.5. The thermodynamic fitting curves are more consistent with the Langmuir model and the adsorption capacities of the bifunctional composites for Hg(II) varied from 1.63 to 1.94 mmol g−1 at 25°C according to the Langmuir model. The kinetics curves are more fitted to the pseudo-second-order model and the composites could selectively adsorb Hg(II) in a series of binary metal ions solution. The elution regeneration tests showed that the adsorption rate could still reach 78% after repeat cycle three times. It is expected that the bifunctional PSQ/CNTs magnetic composites can be potentially applied to remove low concentration Hg(II) from waste water.

D-Penicillamine prolongs survival and lessens copper-induced toxicity in Drosophila melanogaster

ABSTRACT D-penicillamine (DPA) is an amino-thiol that has been established as a copper chelating agent for the treatment of Wilson’s disease. DPA reacts with metals to form complexes and/or chelates. Here, we investigated the survival rate extension capacity and modulatory role of DPA on Cu2+-induced toxicity in Drosophila melanogaster. Adult Wild type (Harwich strain) flies were exposed to Cu2+ (1 mM) and/or DPA (50 μM) in the diet for 7 days. Additionally, flies were exposed to acute Cu2+ (10 mM) for 24 h, followed by DPA (50 μM) treatment for 4 days. Thereafter, the antioxidant status [total thiol (T-SH) and glutathione (GSH) levels and glutathione S-transferase and catalase activities] as well as hydrogen peroxide (H2O2) level and acetylcholinesterase activity were evaluated. The results showed that DPA treatment prolongs the survival rate of D. melanogaster by protecting against Cu2+-induced lethality. Further, DPA restored Cu2+-induced depletion of T-SH level compared to the control (P < 0.05). DPA also protected against Cu2+ (1 mM)-induced inhibition of catalase activity. In addition, DPA ameliorated Cu2+-induced elevation of acetylcholinesterase activity in the flies. The study may therefore have health implications in neurodegenerative diseases involving oxidative stress such as Alzheimer’s disease.

Inorganic and Hybrid (Organic–Inorganic) Lamellar Materials for Heavy metals and Radionuclides Capture in Energy Wastes Management—A Review

The energy industry (nuclear, battery, mining industries, etc.) produces a large quantity of hazardous effluents that may contain radionuclides (137Cs and 90Sr in particular) and heavy metals. One of the hardest tasks of environmental safety and sustainable development is the purification of wastewater holding these pollutants. Adsorption is one of the most powerful methods for extracting toxic compounds from wastewater. This study reviews the usefulness of clay minerals as adsorbent for removing these hazardous elements to clean up energy production processes. Phyllosilicates are able to extract several heavy metals from effluent, as widely examined. A particular focus is given to synthetic phyllosilicates and their abilities to entrap heavy metals with a special attention paid to those synthesized by sol-gel route. Indeed, this method is attractive since it allows the development of organic–inorganic hybrids from organosilanes presenting various functions (amino, thiol, etc.) that can interact with pollutants. Regarding these pollutants, a part of this review focuses on the interaction of lamellar materials (natural and synthetic phyllosilicates as well as layered double hydroxide) with heavy metals and another part deals with the adsorption of specific radionuclides, cesium and strontium.