Redox-neutral electrochemical decontamination of hypersaline wastewater with high technology readiness level.

Industrial hypersaline wastewaters contain diverse pollutants that harm the environment. Recovering clean water, alkali and acid from these wastewaters can promote circular economy and environmental protection. However, current electrochemical and advanced oxidation processes, which rely on hydroxyl radicals to degrade organic compounds, are inefficient and energy intensive. Here we report a flow-through redox-neutral electrochemical reactor (FRER) that effectively removes organic contaminants from hypersaline wastewaters via the chlorination-dehalogenation-hydroxylation route involving radical-radical cross-coupling. Bench-scale experiments demonstrate that the FRER achieves over 75% removal of total organic carbon across various compounds, and it maintains decontamination performance for over 360 h and continuously treats real hypersaline wastewaters for two months without corrosion. Integrating the FRER with electrodialysis reduces operating costs by 63.3% and CO2 emissions by 82.6% when compared with traditional multi-effect evaporation-crystallization techniques, placing our system at technology readiness levels of 7-8. The desalinated water, high-purity NaOH (>95%) and acid produced offset industrial production activities and thus support global sustainable development objectives.

Property Enhancement of Waste Printed Circuit Boards Powders Reinforced Polypropylene by In Situ Magnesium Hydroxide Impregnation from Waste Lye.

Using alkali pretreatment can effectively remove residual variable-valence metals from non-metallic powder (WPCBP) in waste printed circuit boards. However, substantial amounts of waste lye are generated, which causes secondary pollution. On this basis, this study innovatively utilized waste alkali lye to prepare nano-magnesium hydroxide. When the dispersant polyethylene glycol 6000 was used at a dosage of 3 wt.% of the theoretical yield of magnesium hydroxide, the synthesized nano-magnesium hydroxide exhibited well-defined crystallinity, good thermal stability and uniform particle size distribution, with a median diameter of 197 nm. Furthermore, the in situ method was selected to prepare WPCBP/Mg(OH)2 hybrid filler (MW) and the combustion behavior, thermal and mechanical properties of PP blends filled with MW were evaluated. The combustion behavior of the PP/MW blends increased with the increasing hybrid ratio of Mg(OH)2, and the MW hybrid filler reinforced PP blends showed better thermal and mechanical properties compared to the PP/WPCBP blends. Furthermore, the dynamic mechanical properties of the PP/MW blends were also increased due to the improved interfacial adhesion between the MW fillers and PP matrix. This method demonstrated high economic and environmental value, providing a new direction for the high value-added utilization of WPCBP.

Glucans with Different Degrees of Polymerization from Leuconostoc mesenteroides CICC6055: Analysis of Physicochemical Properties and Intestinal Prebiotic Function.

This study explored the physicochemical properties and prebiotic activities of glucans and oligoglucans. Oligoglucans were obtained through the fermentation of Leuconostoc mesenteroides CICC6055 and the glucansucrase of strain CICC6055, while glucans were obtained only through fermentation. Thin-layer chromatography and high-performance liquid chromatography identified enzymatically synthesized oligoglucans with a higher yield. Differential scanning calorimetry and derivative thermogravimetry analyses revealed the heat resistance of the glucans and oligoglucans at 280-300 °C. Fourier transform-infrared spectroscopy and nuclear magnetic resonance analyses demonstrated that their main chains were linked with α-1,6-glycosidic bonds accompanied by glucose residue branching. In vitro fermentation experiments demonstrated that they not only improved the contents of short-chain fatty acids but also raised the abundance of predominant flora, such as Bacteroides, Firmicutes, Verrucomicrobia, and Proteobacteria. These results implicate glucansucrase as an efficacious tool for the enzyme synthesis of oligoglucans. Furthermore, both polysaccharides with different degrees of polymerization may be beneficial in maintaining a healthy human gut.

Output-Feedback stabilization for stochastic nonlinear systems with Markovian switching and time-varying powers.

This paper investigates the output-feedback stabilization for stochastic nonlinear systems with both Markovian switching and time-varying powers. Specifically, by developing a novel dynamic gain method and using the Itô formula of Markovian switching systems, a reduced-order observer with a dynamic gain and an output-feedback controller are designed. By using advanced stochastic analysis methods, we show that the closed-loop system has an almost surely unique solution and the states are regulated to the origin almost surely. A distinct feature of this paper is that even though there is no Markovian switching, our design is also new since it can deal with nonlinear growth rate, while the existing results can only deal with constant growth rate. Finally, the effectiveness of the design method is verified by a simulation example.

Enhancing the Reduction Kinetics of LiSF6 Batteries by Dispersed Cobalt Phthalocyanines on Porous Carbon.

Reducing SF6 (as gas cathode) in Li batteries is a promising concept for the double benefit of mildly converting greenhouse SF6 and providing a high theoretical energy density of 3922 Wh kg-1 . However, the reduction process is hampered by its sluggish kinetics. Here, cobalt phthalocyanine (CoPc) molecules immobilized on porous carbon matrix are, for the first time, introduced to the LiSF6 chemistry to deliver an enhanced energy density. It is revealed that the high redox potential of Co(II)Pc/[Co(I)Pc]- (≈2.85 V) facilitates the formation of Co(I)N4 sites to catalyze the SF6 electrochemical reduction. By using highly porous holey nitrogen-doped carbon nanocages as carbon matrix, the LiSF6 cells deliver a high discharge voltage of 2.82 V at 50 mA gC+CoPc -1 and an unprecedented areal capacity of 25 mAh cm-2 at 0.1 mA cm-2 , much superior to previous results. This work opens up new possibilities for high-efficiency conversion of SF6 in lithium batteries.