Enhanced removal of Co(II) and Ni(II) from high-salinity aqueous solution using reductive self-assembly of three-dimensional magnetic fungal hyphal/graphene oxide nanofibers

In Situ Synthesis of NH2-MIL-53-Al/PAN Nanofibers for Removal Co(II) through an Electrospinning Process

In this study, researchers developed a novel composite material called NH2-MIL-53-Al/PAN, which consists of metal-organic frameworks (MOFs) grown on electrospun PAN nanofibers (NFs). The successful formation of the composite was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR), and the hydrophilicity of NH2-MIL-53-Al/PAN was demonstrated by the water contact angle (WCA). Batch experiments were conducted to investigate the adsorption performance of Co(II) under different conditions. The maximum adsorption capacity reached 58.72 mg/g, and almost 95% of the adsorption was achieved within the first 6 h. The adsorption process was found to be spontaneous and endothermic and followed the pseudo-second-order kinetics and Langmuir models. Chemisorption and molecular layer adsorption are the main mechanisms of adsorption, and X-ray photoelectron spectroscopy (XPS) analysis further reveals that the interaction between the adsorbent and cobalt is a coordination interaction. In this study, NH2-MIL-53-Al was grown in situ on PAN to ensure effective loading of MOFs and prevent agglomeration during the NF mixing process. This approach successfully addressed the challenge of exposing active sites within the embedded MOF crystals. Additionally, it overcame the difficulty of recycling traditional MOF adsorbents. As a result, the exceptional performance of MOF NFs offers a promising solution for the efficient removal of cobalt-containing wastewater.

Development of nanofibrous scaffolds containing polylactic acid modified with turmeric and hydroxyapatite/vivianite nanoparticles for wound dressing applications

Damaging the outer layer of the body (the skin) has been a common issue for decades. Fabrication of nanofibrous membranes via the electrospinning technique for the sake of making the wound healing process more facile has caught a lot of interest. For this purpose, a polymeric scaffold of polylactic acid (PLA) was doped with nanoparticles with different concentrations of turmeric/hydroxyapatite/vivianite/graphene oxide. The obtained membrane was tested by XRD, SEM, FTIR, and XPS. The surface topography of the scaffold has experienced changes upon adding different concentrations of the nanoparticles. The contact angle was measured by water droplets. It accentuated change in CA starting from 43.9o for pure condition of PLA to 67.7o for PLA/turmeric/vivianite. The thermogravimetric analysis (TGA) test stated that the PLA scaffold features are thermally stable in relatively high-temperature conditions initiating from room temperature to about 300 °C, meeting the maximum loss in mass of about 5 %. The cell viability was carried out in prepared vitro for the sample which contains PLA/turmeric/vivianite/GO, it was elucidated that the IC50 was around 3060 μg/ml.

Recent Progress in Multifunctional Graphene-Based Nanocomposites for Photocatalysis and Electrocatalysis Application

The global energy shortage and environmental degradation are two major issues of concern in today's society. The production of renewable energy and the treatment of pollutants are currently the mainstream research directions in the field of photocatalysis. In addition, over the last decade or so, graphene (GR) has been widely used in photocatalysis due to its unique physical and chemical properties, such as its large light-absorption range, high adsorption capacity, large specific surface area, and excellent electronic conductivity. Here, we first introduce the unique properties of graphene, such as its high specific surface area, chemical stability, etc. Then, the basic principles of photocatalytic hydrolysis, pollutant degradation, and the photocatalytic reduction of CO₂ are summarized. We then give an overview of the optimization strategies for graphene-based photocatalysis and the latest advances in its application. Finally, we present challenges and perspectives for graphene-based applications in this field in light of recent developments.

Combination mechanism of the ternary composite based on Fe3O4-chitosan-graphene oxide prepared by solvothermal method

Magnetic nanohybrid combining chitosan and graphene have demonstrated promising application in environmental remediation. Herein, ternary composite MCG based on Fe₃O₄, chitosan (CS) and graphene oxide (GO) was facilely prepared via solvothermal method. The as prepared composite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman, Brunauer/Emmett/Teller-Barret/Joyner/Halenda (BET-BJH) and thermo gravimetric-differential thermal analysis (TG-DTA). The combination mechanism of MCG was unveiled via employing the hard-soft acid-base (HSAB) theory and spectroscopic investigations including X-ray photoelectron spectroscopy (XPS), Ultraviolet-visible (UV-Vis) and fluorescent emission spectra. Particularly, combination mechanism of MCG was elucidated by the probable site to site interaction of the couplet components in MCG, as follows. (1) CS-Fe₃O₄. The primary interaction is N(NH₂)-Fe(III), electron donates from N to Fe, transforming one half of the amino groups of chitosan into positive N⁺. (2) GO-CS. Amidation reaction is the primary interaction form, converting the other half of the amino groups of chitosan into -C(O)NH-. (3) GO-Fe₃O₄. Dominant interactions are those of epoxy, hydroxyl and aromatic ring with Fe(III). Moreover, MCG exhibits fair adsorption performance on divalent heavy metals in six consecutive cycles. These explorations may shed light on the design of efficient adsorbent based on Fe₃O₄-chitosan-graphene architecture.

Electrochemical detection of copper(II) in environmental samples using Penicillium sp. IITISM_ANK1 based biosensor

Detection of toxic metals at the lowest of their concentration in a variety of matrices has become a necessity due to the widespread and persistent nature of the contaminant. In this context, biosensors provide a viable alternative to the large sophisticated instrumentation. This study focuses on the development of a cost-effective fungal biomass-based biosensor that can be used for the detection of Cu(II). The fungal cells were pretreated with formaldehyde and studied with various spectroscopic studies. It was observed that the carbonyl groups along with amine groups played role in the sorption of copper ions which were stripped in an electrolytic solution to quantify the metal. Herein the dried fungal biomass was chemically activated and used to prepare a novel graphite paste electrode by repurposing a plastic pipette tip. The factors affecting the detection signal were optimized in further study. The electrochemical characterization revealed that the prepared bio-electrode was capable of detecting Cu in the range of 1 × 10^-7 M to 2 × 10^-5 M.

Recent advances in the construction of biocomposites based on fungal mycelia

In recent years, environmental problems have become increasingly serious, significantly effecting the ecosystem and human health. To deal with the problem of environmental pollution in an eco-conscious way, sustainable composite biomaterials are being produced. Mycelium-based composite biomaterials combine biological systems with substrates such as nanomaterials or agricultural and industrial wastes, which can complement each other's advantages or turn waste into a useful resource. Such materials can solve practical wastewater problems as well as replace plastic products, thus reducing plastic pollution and contributing to the green transition of the environment. In this review, we summarized the recent findings of studies on these materials, indicating future research directions.

Biodegradation of di-n-octyl phthalate by Gordonia sp. Lff and its application in soil

A previous isolated Gordonia sp. (Lff) was used to degrade di-n-octyl phthalate (DOP) contamination in both aqueous solution and soil. The influence of temperature, pH, inoculum size, salt content and initial concentration of DOP on DOP degradation by Lff were analysed. The response of soil bacterial community to DOP and Lff was also analysed by Illumina MiSeq sequence method. Results showed that the optimal temperature, pH, inoculum size and salt content were 35^oC, 8.0, 5% and <5%, respectively. Under the optimal condition, more than 91.25% of DOP with different initial concentrations (100-2000 mg/L) could be degraded by Lff. Kinetics analysis indicated that biodegradation of DOP by Lff could be described by first-order kinetics (R² > 0.917) with the half-life (t_1/2) changing irregularly between 0.58 and 0.83 d. In addition, Lff enhanced the removal of DOP in soil and alleviated the toxicity of DOP on soil microorganisms. Furthermore, its influence on soil bacterial community is not obvious. These results suggested that Lff was effective in remediating DOP contamination in different environments.

Simultaneous Removal of Cu2+, Cd2+ and Pb2+ by Modified Wheat Straw Biochar from Aqueous Solution: Preparation, Characterization and Adsorption Mechanism

As an eco-friendly and efficient adsorbent for removal of potential toxic metals from aqueous solution, biochar has received widespread attention. In the present study, wheat straw biochar (BC) and corresponding modified biochar (HNC) were used to remove Cu²⁺, Cd²⁺ and Pb²⁺ from an aqueous solution. The influence of the environment factors on metals adsorption and adsorption mechanism were discussed in detail. The results showed that the HNC had porous structures and owned ample functional groups (-OH, -COOH and C-N groups) compared with the BC. In the single system, the adsorption capacities of HNC for Cu²⁺, Cd²⁺ and Pb²⁺ at a pH of 5.5 were 18.36, 22.83 and 49.38 mg/g, which were 76.89%, 164.36% and 22.75% higher than that of the BC, respectively. In addition, the adsorption process of Cu²⁺ and Cd²⁺ on BC and HNC fitted to the Langmuir isotherm model and pseudo-second-order kinetics, but the adsorption of Pb²⁺ on BC and HNC fitted to the Langmuir isotherm model and pseudo-first-order kinetics. Adsorption isotherms indicated that the adsorption of Cu²⁺, Cd²⁺ and Pb²⁺ by BC and HNC was a spontaneous endothermic process. The competitive adsorption of mixed metal ions (Cu²⁺, Cd²⁺ and Pb²⁺) revealed that HNC was more preferential to adsorb Cu²⁺ compared with Cd²⁺ and Pb²⁺. Furthermore, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that the main adsorption mechanisms were surface complexation and precipitation, and the adsorbed Cu²⁺, Cd²⁺ and Pb²⁺ on HNC mainly exist as CuO, Cd(OH)₂, Pb₃O₄ and Pb(OH)₂.

The dynamics of public spending on sustainable green economy: role of technological innovation and industrial structure effects

In order to achieve the goal of sustainable green economic development, it is necessary to conduct a comprehensive assessment of the efficiency of the green economy and compare it with emission reductions. The green economy idea is a much-discussed solution to economic growth. Therefore, this study investigated the impact of government spending on the performance of the green economy of various countries under the "Belt and Road" (BRI) initiative project. The data were analyzed using the BRI economy panel data from 2008 to 2018. The generalized method of moments (GMM) was used to estimate the effect of government expenditures on education and research and development (R&D) on green economic performance index (GEE) in BRI countries. The results reveal that during the study period, BRI countries have experienced an upward transition towards green development, except for Pakistan and Bangladesh; their GEE decreased gradually from 2010 to 2018. Further, the findings of the system GMM revealed that both education and R&D have a positive impact on the green economy. Moreover, the compositional and technological effects of the overall sample were verified with the GMM process. Nevertheless, the sub-sample results revealed a heterogeneous impact on countries with a high per capita GDP. Following the results, useful policy measures for promoting sustainable green economic development have been proposed.

A molecular modeling on the boron trichloride gas detection by S- and Cr-doped graphyne

Here, we scrutinize the adsorption of boron trichloride (BCl₃) on pure, S-doped, and Cr-doped graphyne by means of density functional theory (DFT) calculations. BCl₃ interacts weakly with pure graphyne, so it cannot be employed as a sensor. Despite the strengthening of interaction through S-doping, we cannot still employ the S-doped sheet as a sensor. Nevertheless, there is a considerable increase in the sensitivity and reactivity of the sheet through substituting the transition metal Cr for the C. There is a reduction in the HOMO-LUMO gap of Cr-doped graphyne from 2.18 to 1.38 eV when BCl₃ is adsorbed, thereby increasing the electrical conductivity to a great extent. Hence, it is possible to convert the considerable change in conductivity into an electronic signal, which demonstrates the encouraging nature of Cr-doped graphyne as a sensor to detect BCl₃. Additionally, the adsorption process reduces the work function of graphyne to a great extent, which demonstrates that we can also employ it as a work function-type sensor for detecting BCl₃.

Sequestration of free and chelated Ni(II) by structural Fe(II): Performance and mechanisms

Ni(II) and chelated Ni(II) in wastewater are of environmental concern. This study explores the sequestration potential of structural Fe(II) in solid phase (≡Fe(II)) on Ni(II) and EDTA-Ni(II) using freshly prepared ferrous hydroxyl complex (FHC) as the Fe(II)-bearing mineral. The 1 mM Ni(II) could be completely sequestrated in 20 min by 3 mM FHC, although the sequestrated Ni(II) was partially released after 20 min. It is calculated that up to 156 mg Ni(II)/g Fe(II) can be sequestrated by ≡Fe(II) under neutral pH and anaerobic condition. According to the characterizations of the solid products, the large surface area for Ni(II) adsorption and the high ≡Fe(II) reduction capacity for Ni(II) reduction are the main contributors to the Ni(II) sequestration. After the reaction, the FHC is transformed to stable Fe-Ni layered double hydroxides. The concomitant ions can be either promotional or inhibitory to the sequestration performance depending on the ion type. The combination of FHC and Fe(III) can effectively sequestrate EDTA-Ni(II), whereas FHC alone has a low efficiency. Fe(III) substitutes Ni(II) from the EDTA-Ni(II), benefiting the subsequent Ni(II) sequestration by ≡Fe(II). This study demonstrates that ≡Fe(II) suspension is an cost-effective option for remediating Ni(II)-containing wastewater.

Assessing the role of financing in sustainable business environment

Speedy economy-wide transition to less carbon-intensive energy generations sources needs extra sizable financing on ground-breaking, nevertheless, risky and less carbon-intensive generation sources. Maximizing the maximum non-government financing needs using the appropriate policy tools, however, fiscal strategies and directives have been thoroughly studied, systematic quantifiable indications about the impacts of government explicit financing is inadequate. We equally give an initial measurable calculation of the impact of government explicit financing on non-government financing into conventional electricity generation sources for 22 OECD nations in the year 2001-2018. Applying FGLS and non-dynamic and non-static GMM regressors, we discover that government financing unilaterally has an explicit and nevertheless reliably the most impacts on non-government financing movements compared to feed-in tariffs (FiTs), taxes, and renewable purchase obligations (RPS) in all and regarding wind and solar sources differently. Ramifications for policy geared towards fast-tracking the energy transition are deliberated. We highlighted those important dedications to scale-up wind and solar energy demands organized by financiers such as asset funding. Furthermore, to arrive at the energy crossover to a carbon-free power system, government and non-government financiers have to continue financing and expand their activities in financing studies, demonstration, and initial scale-up. We reveal that the delivery of government finance is directly correlated with non-government funding movements. Furthermore, we postulate that government policy incentives for non-government financing, nevertheless, have impacts of unconventional energy sources share on non-government financing more than those of FiTs. Ultimately, the supply of conventional fuels is a significant impediment to solar energy financing, while the existence of other sources of cleaner energies promotes non-government climate finance.

Assessing the role of financing in sustainable business environment

Speedy economy-wide transition to less carbon-intensive energy generations sources needs extra sizable financing on ground-breaking, nevertheless, risky and less carbon-intensive generation sources. Maximizing the maximum non-government financing needs using the appropriate policy tools, however, fiscal strategies and directives have been thoroughly studied, systematic quantifiable indications about the impacts of government explicit financing is inadequate. We equally give an initial measurable calculation of the impact of government explicit financing on non-government financing into conventional electricity generation sources for 22 OECD nations in the year 2001-2018. Applying FGLS and non-dynamic and non-static GMM regressors, we discover that government financing unilaterally has an explicit and nevertheless reliably the most impacts on non-government financing movements compared to feed-in tariffs (FiTs), taxes, and renewable purchase obligations (RPS) in all and regarding wind and solar sources differently. Ramifications for policy geared towards fast-tracking the energy transition are deliberated. We highlighted those important dedications to scale-up wind and solar energy demands organized by financiers such as asset funding. Furthermore, to arrive at the energy crossover to a carbon-free power system, government and non-government financiers have to continue financing and expand their activities in financing studies, demonstration, and initial scale-up. We reveal that the delivery of government finance is directly correlated with non-government funding movements. Furthermore, we postulate that government policy incentives for non-government financing, nevertheless, have impacts of unconventional energy sources share on non-government financing more than those of FiTs. Ultimately, the supply of conventional fuels is a significant impediment to solar energy financing, while the existence of other sources of cleaner energies promotes non-government climate finance.

Preparation of new bio-based chitosan/Fe2O3/NiFe2O4 as an efficient removal of methyl green from aqueous solution

Modified chitosan with various functional groups has high potential as an efficient adsorbent in removing water pollution. In this study, new magnetic adsorbent, bio-based chitosan/Fe₂O₃/NiFe₂O₄, was successfully prepared by green chemistry route involving mixing of chitosan as core moiety and Fe₂O₃/NiFe₂O₄ nanocomposite, and slow evaporation of solvent. Synthesized chitosan/Fe₂O₃/NiFe₂O₄ was characterized by FT-IR, TGA, XRD, VSM and FE-SEM. The FT-IR and XRD results confirmed that the successful preparation of chitosan/Fe₂O₃/NiFe₂O₄. Uniform dispersion of Fe₂O₃/NiFe₂O₄ nanoparticles with low aggregation was confirmed by FE-SEM. The as-prepared magnetic chitosan/Fe₂O₃/NiFe₂O₄ was developed as solid phase adsorbent to remove methyl green (MG) dye from aqueous solutions. Several important parameters such as contact time, pH, temperature and adsorbent dosage were investigated systematically. The high and fast MG dye removal (≈ 80%) occurs after 30 min. The optimal conditions for MG removal was recorded at pH = 8, contact time of 60 min, adsorbent dosage of 0.2 g and 25 °C and displayed a high MG dye removal percentage of 96.51% and adsorption capacity of 77.22 mg/g.

Investigating fullerene-oxide nanostructure as an adsorbent of ammonia: Complexation efficiency by density functional theory

A model of OC20 fullerene-oxide (FO) was investigated in this work for adsorbing the ammonia (NH3) substance by the hypothesis of formations of bimolecular complexes of the two substances. To affirm such hypothesis, the models of singular NH3 and FO were optimized to reach the minimized energy structures and all possibilities of their interactions configurations were examined. As a consequence, three NH3@FO bimolecular complex models were obtained for reaching the point of complex formations. Details of interactions indicated both direct and indirect contributions of the oxidized region of FO to interactions with both H and N atomic sites of NH3. In this regard, CPLX3 with two types of H. . . O and N. . . C interactions was seen to be at the highest strength of adsorption and complex formation in comparison with CPLX1 and CPLX2 models including only one interaction of each of H. . . O and N. . . C type, respectively. Moreover, the obtained electronic molecular orbital features revealed the sensor function of FO material versus the NH3 substance. As a consequence, the hypothesis of NH3@FO complexes formation was affirmed with two proposed functions of removal and detection for the investigated FO material. All results of this work were obtained by details through performing density functional theory (DFT) calculations.

Influences of modified biochar on metal bioavailability, metal uptake by wheat seedlings (Triticum aestivum L.) and the soil bacterial community

A 6 weeks pot culture experiment was carried out to investigate the stabilization effects of a modified biochar (BCM) on metals in contaminated soil and the uptake of these metals by wheat seedlings. The results showed that the application of BCM significantly increased the soil fertility, the biomass of wheat seedling roots increased by more than 50%, and soil dehydrogenase (DHA) and catalase (CAT) activities increased by 369.23% and 12.61%, respectively. In addition, with the application of BCM, the diethylenetriaminepentaacetic acid extractable (DTPA-extractable) Cd, Pb, Cu and Zn in soil were reduced from 2.34 to 0.38 mg/kg, from 49.27 to 25.65 mg/kg, from 3.55 mg/kg to below the detection limit and from 4.05 to 3.55 mg/kg, respectively. Correspondingly, the uptake of these metals in wheat roots and shoots decreased by 62.43% and 79.83% for Cd, 73.21% and 66.32% for Pb, 57.98% and 68.92% for Cu, and 40.42% and 43.66% for Zn. Furthermore, BCM application decreased the abundance and alpha diversity of soil bacteria and changed the soil bacterial community structure dramatically. Overall, BCM has great potential for the remediation of metal-contaminated soils, but its long-term impact on soil metals and biota need further research.