Facile Removal Research Articles

Facile removal of caffeine in 30 seconds using tea waste-derived porous carbon: Effect of surface area and adsorption technique

BackgroundThe release of contaminants from various pharmaceutical sources into water bodies has severely polluted the resources, making them unfit for utilization. Among the pharmaceutical wastes, caffeine has been identified as a serious pollutant due to its widespread consumption by the general public. Biomass-derived porous materials have been considered a suitable adsorbent material for wastewater treatment, owing to their low cost, reusability, and eco-friendly nature. However, the main drawback of adsorbents has been the low maximum adsorption capacity, which has not been given enough attention. MethodsIn this work, we have synthesized porous carbon from tea waste with high specific surface area (2260.82 m2/g) by activating with KOH in nitrogen atmosphere. Further, adsorption studies were performed using shaker and spin column technique. SignificanceThe material was used to remove caffeine in 30 s, using the spin column technique. The material can be recycled with the same spin column and can be reused up to three cycles without a decrease in performance. The maximum adsorption capacity of caffeine at room temperature was found to be 491.4 mg/g, outperforming many reported adsorbents. When considered together, this group of materials has the potential to be used as a cost-effective remedy for environmental-related concerns, especially for large-scale wastewater treatment applications.

Colossal C130 Fullertubes: Soluble [5,5] C130-D5h(1) Pristine Molecules with 70 Nanotube Carbons and Two 30-Atom Hemifullerene End-caps.

We report the seminal experimental isolation and DFT characterization of pristine [5,5] C130-D5h(1) fullertubes. This achievement represents the largest soluble carbon molecule obtained in its pristine form. The [5,5] C130 species is the highest aspect ratio fullertube purified to date and now surpasses the recent gigantic [5,5] C120-D5d(1). In contrast to C90, C100, and C120 fullertubes, the longer C130-D5h has more nanotubular carbons (70) than end-cap fullerenyl atoms (60). Starting from 39,393 possible C130 isolated pentagon rule (IPR) structures and after analyzing polarizability, retention time, and UV-vis spectra, these three layers of data remarkably predict a single candidate isomer and fullertube, [5,5] C130-D5h(1). This structural assignment is augmented by atomic resolution STEM data showing distinctive and tubular "pill-like" structures with diameters and aspect ratios consistent with [5,5] C130-D5h(1) fullertubes. The high selectivity of the aminopropanol reaction with spheroidal fullerenes permits facile separation and removal of fullertubes from soot extracts. Experimental analyses (HPLC retention time, UV-vis, and STEM) were synergistically used (with polarizability and DFT property calculations) to down select and confirm the C130 fullertube structure. Achieving the isolation of a new [5,5] C130-D5h fullertube opens the door to application development and fundamental studies of electron confinement, fluorescence, and metallic character for a fullertube series of molecules with systematic tubular elongation. This [5,5] fullertube family also invites comparative studies with single-walled carbon nanotubes (SWCNTs), nanohorns (SWCNHs), and fullerenes.

Non-conventional, burnt Shorea robusta leaf extract mediated green synthesis of zinc oxide nanoparticles and facile removal of eriochrome black T dye from water

The present study evaluates the synthesis of zinc oxide nanoparticles (ZnO NPs) using water extract of Sal leaves (Shorea Robusta) for efficient removal of Eriochrome black-T from the water and wastewater. The material is characterized using FESEM, FTIR, EDX, pHzpc, XRD, BET, and TGA analysis. XRD confirmed the synthesis of ZnO with an average crystallite size of 35.24 nm a surface area of 95.939 m2/g and a pore volume of 0.280 cm3/g. The pHzpc of the material is 7.45. The study evaluates the effects of contact time (0–100 min), pH (3–10), concentration (10–50 mg/L), and temperature (298–328K). The Langmuir isotherm model (R2 = 0.993) and pseudo-second-order kinetic model (R2 = 0.998) were found to be the best-fit models. The maximum uptake capacity is 265.554 mg/g. The interaction is spontaneous (ΔG° −12.889 to–14.898 kJ/mol), endothermic ΔH° (4.290–14.216 kJ/mol) with an increase in spontaneity at the solid-liquid junction. The dye-loaded ZnO NPs were successfully regenerated in dilute NaOH solution and 1:1 methanol water, achieving regeneration efficiencies of 78% and 60%, respectively. The reusability of the ZnO NPs was ascertained for up to three consecutive cycles.

Rapid on-demand in-situ gelling and dissociation of PEG bottlebrush hydrogel via light-mediated grafting-through polymerization for full-thickness skin wound repair

Developing light-triggered in situ forming dynamical hydrogels with on-demand dissolvable and antioxidation capacities to promote wound healing is highly desired yet challenging. Herein, we prepared an in situ forming bottlebrush hydrogel with on-demand dissolution capacity from two thioctic acid (TA)-functionalized poly(ethylene glycol)s (PEGs) telechelic (TA-PEGs) prepolymers via a light-mediated grafting-through polymerization strategy. In response to light irradiation, TA-PEGs could undergo rapid ring-opening polymerization to generate a highly branched bottlebrush network with dynamic disulfide bonds and simultaneously load water-soluble curcumin complexes with excellent antioxidant activity, enabling fast in situ gelation in 3 min to achieve perfect coverage of wound sites with different shapes. Furthermore, the resulting bottlebrush hydrogel dressing can achieve facile and painless removal of the dressing via rapid on-demand dissolution of the hydrogel during dressing changes. Meanwhile, thanks to its dynamical feature of the disulfide-based network, the hydrogel possesses excellent self-healing ability and shape adaptability that can maintain the interiority of the dressing during application and thus prolong its service life. In vitro evaluation demonstrates that this PEG bottlebrush hydrogel possesses favorable hemocompatibility, cytocompatibility, and antioxidant capacity. More importantly, in vivo experiments confirmed that the hydrogel promotes angiogenesis, dermal collagen synthesis, and alleviates the excessive ROS damage, thus providing more beneficial conditions to accelerate full-thickness skin wound healing.

Implementasi Manajemen Sarana dan Prasarana Dalam Meningkatkan Mutu Pendidikan di MTs Negeri 1 Lebak

This study aims to: Describe, constraints, and solutions from the Implementation of Facilities and Infrastructure Management in Improving the Quality of Education at MTs Negeri 1 Lebak. This research was conducted using a qualitative approach. Data collection techniques in this study used observation, interviews and documentation. The data obtained was then analyzed using qualitative data analysis consisting of: (a) data reduction, (b) data presentation, and (c) drawing conclusions. The research results show that: 1) Planning for facilities and infrastructure at MTs Negeri 1 Lebak, namely coordination meetings, determining the madrasah program, and determining needs. 2) Procurement of facilities and infrastructure at MTs Negeri 1 Lebak, namely carried out by the facilities and infrastructure, then proceed to the Head of TU and known by the Head of Madrasah to submit a proposal to the government 3) Arrangement of facilities and infrastructure at MTs Negeri 1 Lebak, namely proper maintenance by all residents of the madrasa accompanied by a list of persons in charge. 4) The use of facilities and infrastructure at MTs Negeri 1 Lebak, namely scheduling, but the obstacle faced is that the madrasa has 2 separate buildings, making it difficult for the learning process 5) Removal of facilities and infrastructure at MTs Negeri 1 Lebak, which is carried out by means of auctions and grants

Active Surveillance and Contact Precautions for Preventing Methicillin-Resistant Staphylococcus aureus Healthcare-Associated Infections During the COVID-19 Pandemic.

Statistically significant decreases in methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated infections (HAIs) occurred in Veterans Affairs (VA) hospitals from 2007 to 2019 using a national policy of active surveillance (AS) for facility admissions and contact precautions for MRSA colonized (CPC) or infected (CPI) patients, but the impact of suspending these measures to free up laboratory resources for testing and conserve personal protective equipment for coronavirus disease 2019 (COVID-19) on MRSA HAI rates is not known. From July 2020 to June 2022 all 123 acute care VA hospitals nationwide were given the rolling option to suspend (or re-initiate) any combination of AS, CPC, or CPI each month, and MRSA HAIs in intensive care units (ICUs) and non-ICUs were tracked. There were 917 591 admissions, 5 225 174 patient-days, and 568 MRSA HAIs. The MRSA HAI rate/1000 patient-days in ICUs was 0.20 (95% confidence interval [CI], .15-.26) for facilities practicing "AS + CPC + CPI" compared to 0.65 (95% CI, .41-.98; P < .001) for those not practicing any of these strategies, and in non-ICUs was 0.07 (95% CI, .05-.08) and 0.12 (95% CI, .08-.19; P = .01) for the respective policies. Accounting for monthly COVID-19 facility admissions using a negative binomial regression model did not change the relationships between facility policy and MRSA HAI rates. There was no significant difference in monthly facility urinary catheter-associated infection rates, a non-equivalent dependent variable, in the policy categories in either ICUs or non-ICUs. Facility removal of MRSA prevention practices was associated with higher rates of MRSA HAIs in ICUs and non-ICUs.

Polarity and functionality tailored conjugated microporous polymer coatings on silica microspheres for enhanced pollutant adsorption

Many sources of pollution that are generated by modern society are not addressable by conventional methods. Especially organic compounds, like pharmaceutics, are particularly hard to remove from waterbodies. Herein, a new approach is presented using conjugated microporous polymers (CMPs) to coat silica microparticles yielding specifically tailored adsorbents. The CMPs are generated with three different monomers: 2,6-dibromonaphthalene (DBN), 2,5-dibromoaniline (DBA) and 2,5-dibromopyridine (DBPN) respectively coupled to 1,3,5-triethynylbenzene (TEB) via Sonogashira coupling. By optimizing the polarity of the silica surface, all three CMPs were converted into microparticle coatings. The resulting hybrid materials feature the advantages of being adjustable in polarity and functionality, as well as morphology. Sedimentation allows facile removal of the coated microparticles after the adsorption. Further, the expansion of the CMP to a thin coating increases the accessible surface area compared to the bulk material. These effects were demonstrated by the adsorption of the model drug diclofenac. Thereby, the aniline-based CMP proved to be most advantageous due to a secondary crosslinking mechanism of amino and alkyne functionalities. An outstanding adsorption capacity of 228 mg diclofenac per gram of the aniline CMP within the hybrid material was achieved. This represents a five-fold increase compared to the value obtained by the pure CMP material underlining the advantages of the hybrid material.

Phosphonated Polyetheramine-Coated Superparamagnetic Iron Oxide Nanoparticles for Inhibition of Oilfield Scale

Oilfield scale is one of the significant problems in hydrocarbon production in the oil and gas industry. Many research groups have attempted to develop greener chemicals to meet environmental regulations. Magnetic nanoparticles are an intriguing technology due to their multiple properties, such as size effects, surface-to-volume ratio, magnetic separation, specificity, low toxicity, and the ability to control exposure and surface chemistry. In this project, we propose a new method to remove chemicals from the produced fluids by attaching the chemicals to superparamagnetic iron oxide nanoparticles (SPIONs), allowing a facile magnetic removal and reusing and recycling. In principle, the system is fully self-contained, and no chemicals or SPIONs are discharged, reducing the overall environmental footprint. We earlier reported synthesizing and using phosphonated polyetheramines (PPEAs) as environmentally friendly and potent scale inhibitors against carbonate and sulfate oilfield scales. Herein, we report the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with biocompatible trisodium citrate (TSC) as a stabilizer agent to avoid crystal grain growth SPIONs using a coprecipitation approach. The resultant SPIONs-TSC was further functionalized with a partially linear phosphonated polyetheramine (PPEA), as green SI, via electrostatic interaction, affording highly monodisperse SPIONs-TSC-PPEA. The synthesized SPIONs-TSC-PPEA was thoroughly characterized via various spectroscopic and analytical techniques. Moreover, to validate the proof of concept of inhibition, recovering, and recycling SPIONs-based scale inhibitors, a series of static jar tests and high-pressure dynamic tube-blocking tests at 80 bar and 100 °C under oilfield conditions were conducted. The results showed that SPIONs-TSC-PPEA gave excellent inhibition performance against the gypsum scale even when recycled four times. In addition, the morphology of the gypsum scales in the absence and presence of SPIONs-TSC-PPEA was determined using scanning electron microscopy (SEM).

Effective Endotoxin Removal from Chitosan That Preserves Chemical Structure and Improves Compatibility with Immune Cells.

Chitosan is one of the most researched biopolymers for healthcare applications, however, being a naturally derived polymer, it is susceptible to endotoxin contamination, which elicits pro-inflammatory responses, skewing chitosan's performance and leading to inaccurate conclusions. It is therefore critical that endotoxins are quantified and removed for in vivo use. Here, heat and mild NaOH treatment are investigated as facile endotoxin removal methods from chitosan. Both treatments effectively removed endotoxin to below the FDA limit for medical devices (<0.5 EU/mL). However, in co-culture with peripheral blood mononuclear cells (PBMCs), only NaOH-treated chitosan prevented TNF-α production. While endotoxin removal is the principal task, the preservation of chitosan's structure is vital for the synthesis and lysozyme degradation of chitosan-based hydrogels. The chemical properties of NaOH-treated chitosan (by FTIR-ATR) were significantly similar to its native composition, whereas the heat-treated chitosan evidenced macroscopic chemical and physical changes associated with the Maillard reaction, deeming this treatment unsuitable for further applications. Degradation studies conducted with lysozyme demonstrated that the degradation rates of native and NaOH-treated chitosan-genipin hydrogels were similar. In vitro co-culture studies showed that NaOH hydrogels did not negatively affect the cell viability of monocyte-derived dendritic cells (moDCs), nor induce phenotypical maturation or pro-inflammatory cytokine release.

Highly efficient and facile removal of As(V) from water by using Pb‐MOF with higher stable and fluorescence

Metal–organic framework (MOF) materials are promising adsorbents for removing As(V) from sodium arsenate aqueous solutions, because of their high porosity and functional modulability. Two novel Pb(II) complexes {[Pb2(bcabsa)(μ2‐OH)]}n (Pb (bcabsa)) and {[Pb (Hbcabsa)]·(4,4′‐bpy)(H2O)}n (Pb (bcabsabpy)) (H3bcabsa = 4‐(N,N′‐bis(4‐carboxy benzyl)amino)benzene‐sulfonic acid, 4,4′‐bpy = 4,4′‐bipyridine), were hydrothermally synthesized. Pb (bcabsabpy) was characterized by single‐crystal X‐ray diffraction (SC‐XRD), X‐ray photoelectron spectroscopy (XPS), photoluminescence, powder X‐ray diffraction (XRD), and infrared radiation (IR) before and after the adsorption of As(V). In addition, the capacity of Pb (bcabsabpy) to remove arsenic was also investigated. The experimental results showed that Pb (bcabsabpy) had high stability within pH 4–12 and a relatively high As(V) removal rate (&gt;90%) in the pH range of 4–10. The adsorption kinetics followed the pseudo‐second‐order kinetic model, whereas the adsorption isotherm was in agreement with the Langmuir equation. Pb (bcabsabpy) had a high adsorption capacity of As(V) in an aqueous solution (Qmax of 25.51 mg g−1). The fluorescence mechanism of the H3bcabsa, Pb (bcabsa), and Pb (bcabsabpy) are assigned to π‐π*, n‐π*, and π‐π* electron transition processes, respectively.

Tandem Efficient Bromine Removal and Silver Recovery by Resorcinol-Formaldehyde Resin Nanoparticles.

Halogen wastewater greatly threatens the health of human beings and aquatic organisms due to its severe toxicity, corrosiveness, and volatility. Efficient bromine removal is therefore urgently required, while existing Br2-capture materials often face challenges from limited water stability and possible halogen leaking. We report a facile and efficient aqueous Br2 removal method using submicron resorcinol-formaldehyde (RF) resin nanoparticles (NPs). The abundant aromatic groups dominate the Br2 removal by substitution reactions. An excellent Br2 conversion capacity of 7441 mg gRF-1 was achieved by RF NPs that outperform state-of-the-art materials by ∼2-fold, along with advantages including good water stability, low cost, and easy fabrication. Two recycling-coupled (electrochemical or H2O2-involved) Br2 removal routes further reveal the feasibility of in-depth halogen removal by RF NPs. The brominated resin can be downstream upcycled for silver recovery, realizing the harvesting of precious metal, reducing of heavy-metal pollution, and resource utilization of brominated resin.

Multifunctional Chitosan/Xylan-Coated Magnetite Nanoparticles for the Simultaneous Adsorption of the Emerging Contaminants Pb(II), Salicylic Acid, and Congo Red Dye

In this work, we develop chitosan/xylan-coated magnetite (CsXM) nanoparticles as eco-friendly efficient adsorbents for the facile removal of contaminants from water. Characterization of CsXM using Fourier Transform Infra-Red (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Transmission Electron Microscopy (TEM), Zeta potential measurements, and Brunauer-Emmet-Teller (BET) analysis, confirmed the successful preparation of a chitosan/xylan complex coated over magnetite, which is characterized by being mesoporous, thermally stable and of neutral charge. Three contaminants, Pb(II), salicylic acid (SA), and congo red (CR), were chosen as representative pollutants from three major classes of contaminants of emerging concern: heavy metals, pharmaceuticals, and azo dyes. Pb(II), SA, and CR at initial concentrations of 50 ppm were removed by 64.49, 62.90, and 70.35%, respectively, on applying 6 g/L of CsXM. The contaminants were successfully removed in ternary systems, with Pb (II) and SA being more competitive in their adsorption than CR. Adsorption followed the Freundlich isotherm model and the pseudo-second order kinetic model, while the binding was suggested to occur mainly via chemical chelation for Pb(II) and physical interaction for SA and CR, which demonstrates the multifunctional potential of the nanoparticles to capture different contaminants regardless of their charge.

Hierarchical Pt-In Nanowires for Efficient Methanol Oxidation Electrocatalysis.

Direct methanol fuel cells (DMFC) have attracted increasing research interest recently; however, their output performance is severely hindered by the sluggish kinetics of the methanol oxidation reaction (MOR) at the anode. Herein, unique hierarchical Pt-In NWs with uneven surface and abundant high-index facets are developed as efficient MOR electrocatalysts in acidic electrolytes. The developed hierarchical Pt89In11 NWs exhibit high MOR mass activity and specific activity of 1.42 A mgPt-1 and 6.2 mA cm-2, which are 5.2 and 14.4 times those of Pt/C, respectively, outperforming most of the reported MORs. In chronoamperometry tests, the hierarchical Pt89In11 NWs demonstrate a longer half-life time than Pt/C, suggesting the better CO tolerance of Pt89In11 NWs. After stability, the MOR activity can be recovered by cycling. XPS, CV measurement and CO stripping voltammetry measurements demonstrate that the outstanding catalytic activity may be attributed to the facile removal of CO due to the presence of In site-adsorbing hydroxyl species.

Penerapan Manajemen Sarana dan Prasarana Pendidikan di Sekolah Dasar

The purpose of this study was to determine the application of management of educational facilities and infrastructure at SDN 002 Tembilahan Kota, and the factors that influence it. The population in this study was the principal and all school personnel, totaling 29 people at the 002 Tembilahan City State Elementary School. The data in this study were collected using questionnaires, interviews and documentation techniques. Furthermore, the collected data is analyzed using the percentage formula. From the results of the study, it can be concluded as follows: The implementation of educational facilities and infrastructure at the 002 Tembilahan City State Elementary School, reached a score of 79.54%, and was categorized as good, because the figure of 79.54% lies in the 61% - 80% interval. The factors that influence the implementation of facilities and infrastructure management at the 002 Tembilahan State Elementary School are as follows: planning the needs of educational facilities and infrastructure, procurement of educational facilities, storage of facilities and infrastructure, inventory, maintenance and utilization of educational infrastructure facilities, and removal of damaged facilities and infrastructure.

Geopolymer composite spheres derived from graphene-modified fly ash/slag: Facile synthesis and removal of lead ions in wastewater

Geopolymer composite spheres derived from potassium-activated graphene-modified slag/fly ash powder were produced in a polyethylene glycol (PEG 400) solvent. The effect of graphene type (graphene oxide (GO) and few-layered graphene (GNP)) on the pore structure and lead ions (Pb2+) removal performance of the spheres were evaluated. The results showed that the composite spheres modified with GOs (0.1–0.4 wt%) and GNPs (1–4 wt%) could be spheroidized with an improved performance to adsorb Pb2+ in solution. The graphene-containing spheres reached a maximum BET surface area of 68.85 m2/g. Pseudo-second-order and Langmuir isotherm models could express the adsorption process, which was controlled by both monolayer adsorption and chemisorption. The obtained spheres also showed high adsorption capacities for Ni2+, Cu2+, Zn2+ and Cd2+ ions. Chemical, physical, electrostatic, ion exchange and cation-π interaction were attributed to the adsorption mechanism of the spheres. The spheres showed good cycling ability compared to those without graphene, which had potential application in heavy metal wastewater treatment.

Controlled Removal of Organic Dyes from Aqueous Systems Using Porous Cross-Linked Conjugated Polyanilines.

Porous organic materials, as a broad class of functional materials, offer a promising route for low-cost purification of contaminated wastewaters. We have synthesized a range of highly cross-linked conjugated porous polyanilines and optimized their porosity and water dispersibility by tuning reactant feed ratios, previously unreported in the synthesis of such networks. To demonstrate their ability to adsorb model dyes used in the textile industry, we exposed the networks to a range of cationic aromatic dyes, leading to absorption capacities of >100 mg/g, reported for the first time with respect to polyaniline networks. The versatility of the networks was further demonstrated by the preparation of gel composites, producing active gels for efficient and facile removal and recycling, ideal for real-world applications. Finally, chemical modifications of the networks were undertaken to target the removal of model anionic organic dye pollutants, showing the wide applicability of our approach.

Peelable Nanocomposite Coatings: "Eco-Friendly" Tools for the Safe Removal of Radiopharmaceutical Spills or Accidental Contamination of Surfaces in General-Purpose Radioisotope Laboratories.

Radioactive materials are potentially harmful due to the radiation emitted by radionuclides and the risk of radioactive contamination. Despite strict compliance with safety protocols, contamination with radioactive materials is still possible. This paper describes innovative and inexpensive formulations that can be employed as 'eco-friendly' tools for the safe decontamination of radiopharmaceuticals spills or other accidental radioactive contamination of the surfaces arising from general-purpose radioisotope handling facilities (radiopharmaceutical laboratories, hospitals, research laboratories, etc.). These new peelable nanocomposite coatings are obtained from water-based, non-toxic, polymeric blends containing readily biodegradable components, which do not damage the substrate on which they are applied while also displaying efficient binding and removal of the contaminants from the targeted surfaces. The properties of the film-forming decontamination solutions were assessed using rheological measurements and evaporation rate tests, while the resulting strippable coatings were subjected to Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and tensile tests. Radionuclide decontamination tests were performed on various types of surfaces encountered in radioisotope workspaces (concrete, painted metal, ceramic tiles, linoleum, epoxy resin cover). Thus, it was shown that they possess remarkable properties (thermal and mechanical resistance which permits facile removal through peeling) and that their capacity to entrap and remove beta and alpha particle emitters depends on the constituents of the decontaminating formulation, but more importantly, on the type of surface tested. Except for the cement surface (which was particularly porous), at which the decontamination level ranged between approximately 44% and 89%, for all the other investigated surfaces, a decontamination efficiency ranging from 80.6% to 96.5% was achieved.

The Management of Facilities and Infrastructures in Educational Institution

Educational institutions own equipment and resources called facilities and infrastructure that facilitate the delivery of educational services. Infrastructure management is required for successful infrastructure. Inventory is one of the key components of infrastructure management. It involves several steps, including management, implementation, organization, recording, and registration of inventory items. The study employs a qualitative paradigm and literary analysis methods. Primary books and scholarly publications comprising 40 references are used as research sources. The findings indicated that maintaining infrastructure quality and quantity is a goal of the invention focus. Activities involving inventory are fundamentally a continuous process. Additionally, the inventory of educational institutions provides data on the number, quality, wealth, planning, acquisition, and removal of facilities and infrastructure, as well as data on data accountability. Activities related to inventory include tracking purchases and creating reports.

Facile adsorptive removal of dyes and heavy metals from wastewaters using magnetic nanocomposite of zinc ferrite@reduced graphene oxide

• Incorporation of ZnFe 2 O 4 onto rGO improves the adsorption efficiency of rGO. • Pb (II) and MB dye were efficiently adsorbed onto the synthesized MrGO. • Adsorption of Pb(II) and MB onto MrGO follow Langmuir isotherm and PSO kinetic models. • The synthesized MrGO nanocomposite have been used for 5 consecutive cycles. Graphene-based nanomaterials can be tailored as green and excellent adsorbents for wastewater treatment. Herein, reduced graphene oxide was synthesized by a modified Hummer’s method and decorated with zinc ferrite nanoparticles for the efficient adsorptive removal of lead, and methylene blue dye from aqueous solutions. The characteristics of the nanocomposite adsorbent (ZnFe 2 O 4 @rGO, MrGO) were ascertained by various physicochemical tools including: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Field Emission scanning electron microscopy with energy dispersive X-ray spectrometry (FESEM-EDX), X-ray photoelectron spectroscopy (XPS), Zeta potential, and Vibrating sample magnetometer (VSM) analysis. Various parameters, influencing the adsorptive removal of pollutants, were thoroughly explored and optimized including the mass of adsorbent, initial concentration of adsorbate, and medium pH. The synthesized MrGO nano-adsorbent exhibited excellent adsorption capacities towards model pollutants of lead ions and methylene blue dye of 89.8 and 119.0 mg g −1 , respectively. A plausible mechanism of pollutants’ removal on the synthesized nanocomposite was attributed mainly to the vacancy defects and oxygen bearing functional groups of the MrGO nanoparticles’ surfaces. The adsorption isotherms conformed to the Langmuir, rather than the Freundlich, model and followed the PSO kinetic model suggesting a chemisorption process via pollutants monolayers on the MrGO nanoparticles’ surfaces. The synthesized MrGO nanocomposite was excellently stable and reusable for five consecutive cycles; and therefore, it can be a promising adsorbent for the effective removal of pollutants of heavy metals and dyes for environmental remediation purposes.

Selective co-crystallization separation of sucrose-6-acetate from complicated sucrose acylation system and facile removal of co-former: Process optimizations and mechanisms

The searching for the facial and highly efficient separation method of sucrose-6-acetate (SA-6) in the acylation process seems significant for the production of sucralose. In this work, an efficiently selective co-crystallization strategy of SA-6 from the complicated sucrose acylation mixture has been developed, i. e. firstly, selective co-crystallization using acetic acid (HAc) as a cheap and green co-former (operation I), and co-former removal by triethylamine (TEA) (operation II). The crystal structure of SA-6·HAc co-crystal in the operation I has been determined, it is a 3D hydrogen-bonding network with HAc inserting among the SA-6 layers, whose cavity size is 5.56 × 7.54 Å. And the optimization on two operations have been conducted, including HAc dosage, solvent/aliphatic amine types and dosage, separation time/temperature. Based on the optimal conditions, the high SA-6 separation efficiency of 90.33 % in 1.5 h can be achieved, during which relative selectivity coefficient (αX) is lower than 0.003, deacidification ratio (δ) is higher than 99.47 %, and the product purity is 99.86 % (wt). Furthermore, the selective co-crystallization and co-former removal mechanisms were proposed base on crystal structure and theoretical calculations, in which thermally stable co-crystals, proper solvent size and acid-base coupling drive these processes. This strategy can enhance the separation efficiency of acylation process in sucralose production greatly.