Abstract
The safe treatment of heavy metals in wastewater is directly related to human health and social development. In this paper, a new type of recyclable adsorbent is synthesized through the ...oxidation of enhancer and modification with magnetic nanoparticles. The new adsorbent not only inherits the advantages of multiwall carbon nanotubes (6O-MWCNTs), but also exhibits a new magnetic property and further improved adsorption capacity, which is conducive to the magnetic separation and recovery of heavy metals. The adsorption results indicate that multiwall magnetic carbon nanotubes (6O-MWCNTs@Fe
3
O
4
) have a good performance for Pb(II) selective adsorption, with a maximum adsorption capacity of 215.05 mg/g, much higher than the existing adsorption capacity of the same type of adsorbents. Under the action of an external magnetic field, 6O-MWCNTs@Fe
3
O
4
that adsorbed metal ions can quickly achieve good separation from the solution. The joint characterization results of FTIR and XPS show that under the action of both coordination and electrostatic attraction, the C=O bond in the –COOH group is induced to open by the metal ions and transforms into an ionic bond, and the metal ions are stably adsorbed on the surface of 6O-MWCNTs@Fe
3
O
4
. Pb(II) has a stronger attraction than Cu(II) and Cd(II) to the lone pair of electrons in oxygen atoms to form complexes, due to the covalent index of Pb (6.41) is more larger than that of Cu (2.98) and Cd (2.71).These data provide a new type of recyclable adsorbent for the efficient treatment of heavy metal ions in wastewater and enrich relevant theoretical knowledge.
The reduction kinetics of zinc ferrite in CO was investigated under isothermal conditions at different CO concentration and roasting temperature with the help of the thermogravimetric analysis (TGA). ...The reduction of zinc ferrite was a step-wise mechanism. As the model fitting results suggest, the first stage was controlled by the rate of first-order (when CO = 4%) or the second-order (when CO = 6%, 8%) reaction, with the
E
a
in 4%, 6%, and 8% of CO being 91.45 kJ mol
−1
, 73.08 kJ mol
−1
, and 73.49 kJ mol
−1
, correspondingly. Also, the diffusion of reactant proves to constitute the rate-determining step in the second stage, and the reaction model is R2 (contracting cylinder), wherein the
E
a
in 4%, 6%, and 8% of CO is 80.81 kJ mol
−1
, 59.11 kJ mol
−1
, and 59.19 kJ mol
−1
, correspondingly. The generation of magnetite and zinc oxide is the chemical reaction control, and the generation of ferrous oxide, metal iron was the diffusion control. The increase in the CO concentration from 4% to 6% or 8% could decrease the
E
a
and increase the reaction order, consequently, the reductive roasting was accelerated.
Industrial waste salt is classified as hazardous waste to the environment. The organic impurity and its occurrence in industrial waste salt affect the salt resource utilization. In this paper, ...composition quantitative analysis, XRD, TG-DSC, SEM/FIB-SEM coupled with EDS, FTIR, XPS and GC-Ms were chosen to investigate the organic impurity and its occurrence in industrial waste salt. The organic impurities owe small proportion (1.77%) in the specimen and exhibit weak thermal stability within the temperature of 600°C. A clear definition of organic impurity, including 11 kinds of organic compounds, including aldehyde, benzene and its derivatives etc., were detected in the industrial waste salt. These organic impurities, owing (C-O/C-O-C, C-OH/C = O, C-C/CHx/C = C etc.)-containing function group substance, are mainly distributed both on the surface and inside of the salt particles. Meanwhile, the organic substance may combine with metal cations (Ni2+, Mg2+, Cu2+ etc.) through functional groups, such as hydroxide, carbonyl etc., which increases its stability in the industrial waste salt. These findings provide comprehensive information for the resource utilization of industrial waste salt from chemical industry etc.
In this paper, a two-step hydrothermal method was used to prepare NiCo
2
S
4
/N-CNT nanocomposites with excellent cycling performance. N-doped carbon nanotubes occur coordination effect; it is ...conducive to enhancing the overall electrochemical effects of NiCo
2
S
4
. Besides, the introduction of carbon nanotubes (CNTs) greatly improved the cycling stability of the materials. Electrochemical tests show that the NiCo
2
S
4
/N-CNT composite materials have an ultra-high specific capacitance of 1428 F g
−1
at 1 A g
−1
, while the capacitance of pure NiCo
2
S
4
is 733.5 F g
−1
. After 4000 charge and discharge cycles, the capacitance of NiCo
2
S
4
/N-CNT electrode materials still maintains 80.2%, while the retention rate of NiCo
2
S
4
materials is only 60.2%. Compared with the electrochemical performance of NiCo
2
S
4
materials reported by most people, it has greatly improved. Therefore, the NiCo
2
S
4
/N-CNT composite material is a promising electrode material.
Graphical abstract
Using oxalic acid as a reducing agent, hydroquinone (HQ), graphene (GO), and acidified carbon nanotubes (CNTs) were compounded directly to synthesize reduced graphene oxide (rGO)/CNTs/HQ hydrogels by ...a one-step hydrothermal method, and the phase composition and electrochemical properties were studied. During the hydrothermal reaction, the π bond in the hydroquinone molecule will be compounded with the large π bond on the surface of rGO due to the π-π interaction. At the same time, CNTs play a role of spacer and support in rGO/CNTs/HQ and improve the conductivity of rGO/CNTs/HQ. The prepared rGO/CNTs/HQ has a mass-specific capacitance of 219 Fg
−1
at 0.5 Ag
−1
; at 10 Ag
−1
, the mass-specific capacitance retains 81%, confirming its excellent rate performance; After 2000 cycles, the mass ratio capacitance retains 94%, and the cycle performance is excellent.
The preparation process of indium oxide semiconductor nanomaterials was improved gradually, and ultimately, ordered In
2
O
3
fibers with hollow structure were successfully synthesized by ...electrospinning method with a special-made collector. Compared with the other samples, the ordered sample has the biggest specific surface area, the minimum grain size, and the minimum conduction resistance. So it also has the best gas sensitivity, which is more than twice that of other samples.
The H9N2 subtype of avian influenza virus (AIV) is widely prevalent in poultry and wild birds globally, and has become the predominant subtype circulating in poultry in China. The H9N2 AIV can ...directly or indirectly (by serving as a “donor virus”) infect humans, posing a significant threat to public health. Currently, there is a lack of in-depth research on the prevalence of H9N2 viruses in Shanxi Province, central China. In this study, we isolated 14 H9N2 AIVs from October 2020 to April 2022 in Shanxi Province, and genetic analysis revealed that these viruses belonged to 7 different genotypes. Our study on animals revealed that the H9N2 strains we identified displayed high transmission efficiency among chicken populations, and exhibited diverse replication abilities within these birds. These viruses could replicate efficiently in the lungs of mice, with one strain also demonstrating the capacity to reproduce in organs like the brain and kidneys. At the cellular level, the replication ability of different H9N2 strains was evaluated using plaque formation assays and multi-step growth curve assays, revealing significant differences in the replication and proliferation efficiency of the various H9N2 viruses at the cellular level. The antigenicity analysis suggested that these isolates could be classified into 2 separate antigenic clusters. Our research provides crucial data to help understand the prevalence and biological characteristics of H9N2 AIVs in central China. It also highlights the necessity of enhancing the surveillance of H9N2 AIVs.
The ammonium tungstate solution obtained by leaching scheelite with phosphate contains a large amount of phosphorus. For production of qualified ammonium paratungstate products, phosphorus must be ...deeply removed from the ammonium tungstate solution. In this study, a novel process for ammonium phosphate recovery and deep phosphorus removal from the solution was proposed. First, ammonium phosphate was crystallized and separated from the ammonium tungstate solution by blowing ammonia and cooling. Results showed that the crystallization ratio of phosphorus was above 95% under the conditions of an ammonia concentration of 4.18 mol/L, an initial phosphorus concentration ranging from 15 g/L to 30 g/L, a holding time of 60 min and the temperature of 20°C. Then, the small portion of phosphorus remaining in the ammonium tungstate solution was further deeply removed by basic magnesium carbonate percipitation. The phosphorus removal efficiency was above 99% and tungsten loss was less than 0.22% under the following conditions: the basic magnesium carbonate stoichiometric ratio was 1.5, the initial phosphorus concentration was ranging from 0.5 to 4 g/L, the reaction time was 120 min and temperature was 25°C. After phosphorus removal, the concentration of phosphorus in the ammonium tungstate solution was below 10 ppm, which meant deep phosphorus removal was achieved.
To date, there have been three epidemic waves of H5N8 avian influenza worldwide. The current third epidemic wave began in October 2020 and has expanded to at least 46 countries. Active and passive ...surveillance were conducted to monitor H5N8 viruses from wild birds in China. Genetic analysis of 10 H5N8 viruses isolated from wild birds identified two different genotypes. Animal challenge experiments indicated that the H5N8 isolates are highly pathogenic in chickens, mildly pathogenic in ducks, while pathogenicity varied in BALB/c mice. Moreover, there were significant differences in antigenicity as compared to Re-11 vaccine strain and vaccinated chickens were not completely protected against challenge with the high dose of H5N8 virus. With the use of the new matched vaccine and increased poultry immune density, surveillance should be intensified to monitor the emergence of mutant strains and potential worldwide spread
wild birds.
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