Remarkable Adsorption Capacity Research Articles

Highly selective cesium removal under acidic and alkaline conditions using a novel potassium aluminum thiostannate

The pH values of nuclear wastewater are extremely low or high, which make the efficient removal of 137Cs a major concern among the issues for safety management and environmental remediation. Existing metal sulfides for Cs+ adsorption have shown poor performance at acidic and alkaline conditions, and the reason has not been revealed yet. Herein, a novel potassium aluminum thiostannate (KAlSnS-3) adsorbent was designed and its Cs+ adsorption mechanism over a wide pH range was investigated. We hypothesized that Al3+ dopant on Sn4+ sites would allow stable adsorption for Cs+ upon its partial release at acidic and alkaline conditions. As a result, KAlSnS-3 demonstrated excellent adsorption performance across a broad pH range (1–13), and high selectivity toward Cs+, even under high salinity conditions (in tap water Kd = 3.12 × 104 mL/g; and in artificial seawater Kd = 3.42 × 103 mL/g). KAlSnS-3 also exhibited rapid adsorption kinetics (R = 97.6% in the first minute), a remarkable adsorption capacity (259.31 mg/g), and a high distribution coefficient (2.09 × 105 mL/g) toward Cs+. In addition, the high reusability of KAlSnS-3 was observed, suggesting its potential for real-world applications. The mechanism for enhancing performance at low and high pH values was discussed with the evidence of crystallinity, elemental concentrations, and binding energy of electrons based on the concept of electrostatic interactions and chemical affinity. In summary, this work provides insights into the mechanism of Cs+ removal under a wide pH range, and the impressive Cs+ adsorption performance indicates the application potential of KAlSnS-3 in wastewater treatment.

Efficient Splitting of Trans-/Cis-Olefins Using an Anion-Pillared Ultramicroporous Metal–Organic Framework with Guest-Adaptive Pore Channels

Trans- / cis -olefin isomers play a vital role in the petrochemical industry. The paucity of energy-efficient technologies for their splitting is mainly due to the similarities of their physicochemical properties. Herein, two new tailor-made anion-pillared ultramicroporous metal–organic frameworks (MOFs), ZU-36-Ni and ZU-36-Fe (GeFSIX-3-Ni and GeFSIX-3-Fe) are reported for the first time for the efficient trans -/ cis -2-butene ( trans -/ cis -C 4 H 8 ) mixture splitting by enhanced molecular exclusion. Notably, ZU-36-Ni unexpectedly exhibited smart guest-adaptive pore channels for trapping trans -C 4 H 8 with a remarkable adsorption capacity (2.45 mmol∙g −1 ) while effectively rejecting cis -C 4 H 8 with a high purity of 99.99%. The dispersion-corrected density functional theory (DFT-D) calculation suggested that the guest-adaptive behavior of ZU-36-Ni in response to trans -C 4 H 8 is derived from the organic linker rotation and the optimal pore dimensions, which not only improve the favorable adsorption/diffusion of trans -C 4 H 8 with optimal host–guest interactions, but also enhance the size-exclusion of cis -C 4 H 8 . This work opens a new avenue for pore engineering in advanced smart or adaptive porous materials for specific applications involving guest molecular recognition.

A coupling technology of capacitive deionization and carbon-supported petal-like VS2 composite for effective and selective adsorption of lead (II) ions

• ZAC@VS 2 disperses the modified tubular carbon material in VS 2 lamella. • ZAC@VS 2 has improved active sites and conductivity. • ZAC@VS 2 shows considerable specific capacitance and low charging resistance. • ZAC@VS 2 electrode displays a prominent heavy metal ions of lead (II) adsorption capacity and rate. • ZAC@VS 2 electrode has the superior ion selectivity to Pb 2+ than Fe 3+ and Na ± . The conventional separation technologies, like chemical precipitation and adsorption processes, cannot quickly and selectively separate and recycle heavy metal ions from waste. Due to its rich sulfur content and excellent electrical conductivity, vanadium disulfide is a potential material for effectively removing lead from wastewater. The vanadium disulfide material with selective adsorption ability was introduced into CDI technology to construct a coupling technology with both advantages. The N -doped modified ZIF@vanadium disulfide (ZAC@VS 2 ) composites were successfully synthesized by hydrothermal method. Electrosorption experiments show that ZAC@VS 2 material presents the remarkable saturated adsorption capacity to lead(II) ions (239.52 mg/g) in the 500 mg/L PbCl 2 solution. In the triplex blend system (Fe 3+ /Pb 2+ /Na + ) with each solute density of 100 mg/L, the saturated adsorption efficiency of 85.4% to Pb 2+ can still be maintained. In addition, compared with the Langmuir(R 2 =0.873) adsorption isotherm model, the Freundlich model (R 2 =0.922) can be better used to fit the adsorption process, which proves that the adsorption process is multilayered and heterogeneous. XPS tests and competitive adsorption experiments show that the electric double layer (EDL) and complexation together promote the selective adsorption of heavy metal ions by ZAC@VS 2 . ZAC@VS 2 composite electrode shows excellent performance in the removal of lead ions in battery waste liquid, indicating the potential of introducing ZAC@VS 2 into CDI to remove lead ions.

Facile fabrication of phenylenediamine residue derived N, O co-doped hierarchical hyperporous carbon for high-efficient chloroxylenol removal

• Hierarchical hyperporous carbon (HHPC) was derived from phenylenediamine residue. • One-step “carbonization-casting-activation” strategy was used for HHPC synthesis. • The HHPC shows superior chloroxylenol adsorption capacity. • In-situ N/O co-dopped carbon surface enhances the adsorption of chloroxylenol. The chloroxylenol (PCMX) has shown well virucidal efficacy against COVID-19, but the large-scale utilization of which will undoubtedly pose extra environmental threaten. In the present study, the recycled industrial phenylenediamine residue was used and an integrated strategy of “carbonization-casting-activation” using super low-dose of activator and templates was established to achieve in-situ N/O co-doping and facile synthesis of a kind of hierarchical hyperporous carbons (HHPC). The sample of HHPC-1.25–0.5 obtained with activator and template to residue of 1.25 and 0.5 respectively shows super-high specific surface area of 3602 m 2 /g and volume of 2.81 cm 3 /g and demonstrates remarkable adsorption capacity of 1475 mg/g for PCMX in batch and of 1148 mg/g in dynamic column adsorption test. In addition, the HHPC-1.25–0.5 exhibits excellent reusability and tolerance for PCMX adsorption under various ionic backgrounds and real water matrix conditions. The combined physio-chemistry characterization, kinetic study and DFT calculation reveal that the enhanced high performances originate from the hierarchical pore structure and strong electrostatic interaction between PCMX and surface rich pyridinic-N and carbonyl groups.

Efficient removal of Pb(II)/Cu(II) from aqueous samples by a guanidine-functionalized SBA-15/Fe3O4

A mesoporous guanidine functionalized Santa Barbara Amorphous-15(SBA-15)/Fe3O4 magnetic nanoadsorbent (Fe3O4@SBA-15-Gd) was prepared for decontamination of aqueous solutions from Pb(II) and Cu(II) heavy metals. The multistep fabrication route, including hydrothermal SBA-15 synthesis process, in situ magnetization by Fe3O4 magnetic nanoparticles (MNPs) (Fe3O4@SBA-15), post-synthetic method for composites’ modification by 3-aminopropyltriethoxysilane (APTES) (Fe3O4@SBA-15-NH2), and nucleophilic addition to cyanimide to prepare the magnetic Fe3O4@SBA-15-Gd nanoadsorbent was conducted. Moreover, the mesoporous SBA-15 was utilized to support Fe3O4 to diminish the MNPs agglomeration, and the guanidine functional group played a significant role in heavy metal adsorption. Various analyzing approaches were applied to validate the precise structure procedure. The novel adsorbent structure owes to the formation of bidentate chelating agent, guanidine groups, on the mesoporous SBA-15 support through a facile nucleophilic addition. An enhanced adsorption capability was acquired in this study. Hence, the Cu(II) and Pb(II) maximum adsorption capacity in optimized conditions reached ca. 344.82 mg/g and 303.03 mg/g. The obtained spherical-shaped MNPs in Fe3O4@SBA-15-Gd magnetic mesoporous nanoadsorbent presented average particles size ascertained to be ca. 63 nm. The Fe3O4@SBA-15-Gd nanoadsorbent rendered high porosity, high surface area, and abundant adsorption sites fabricated by cost-effective and accessible substance materials. Furthermore, the Freundlich model has explained the adsorption process, and the pseudo-second-order model describes the adsorption kinetics. The Fe3O4@SBA-15-Gd adsorbent was conveniently separated by an external magnet and regenerated three times without a notable decline in adsorption efficiency. Therefore, the prepared magnetic mesoporous nanoadsorbent is a privileged material for heavy metal elimination since it achieved remarkable adsorption capacity, yet more selectivity toward Cu(II) and Pb(II) adsorption via binding to the adsorbent’s chelating groups, and consequently, enhanced heavy metal ion amount decontamination.

Fabrication of a Metal‐Organic Framework Composite Modified with Biomass Activated Carbon (BAC) and Functionalized with NH2 for Efficient p‐Nitrophenol Adsorption

AbstractIn this study, a class of low‐cost, hydrophobic commercial activated carbon (AC) and biomass activated carbon (BAC) modified, NH2 functionalized NH2‐MIL‐53(Al)@(B)AC adsorbents with different AC loading (0∼15 %) was prepared via taking advantages of the MIL‐53(Al), (B)AC−NH2 group. The as‐prepared composites were used for phenolic adsorption. The results indicated that the removal rate of para‐nitrophenol (PNP) over NH2‐MIL‐53(Al)@AC‐10 % was 83.6 %, which is improved by 40.1 % when compared to that of parent NH2‐MIL‐53(Al) (59.4 %). This shows that combination of NH2‐MIL‐53(Al) with AC is an efficient approach to develop an adsorbent with remarkable adsorption capacity. The outstanding adsorption performance of NH2‐MIL‐53(Al)@AC adsorbent originated from the increased surface area and pore structure as well as modified surface property owing to the cooperation of NH2‐MIL‐53(Al) and AC. When BAC was fabricated on NH2‐MIL‐53(Al) instead of AC, the removal rate was further increased to 95.5 %. The adsorption capacity for PNP over NH2‐MIL‐53(Al)@BAC‐10 % is 181 mg g−1 in low concentration range (co=75∼300 mg L−1), which is superior to those reported in most literature. The mechanism for the strong adsorption performance of PNP onto NH2‐MIL‐53(Al)@(B)AC related to the π‐π and acid‐base interactions, and hydrophobic effect.

Scaled-up development of recyclable Pd@ZnO/CuO nanostructure for efficient removal of arsenic from wastewater

The purification of water from hazardous substances, like arsenic (As) containing media which causes chronic disorders, requires special types of technological approaches to tackle this problem. Among the technological advancements, adsorption is considered as one of the easiest techniques used for the treatment and purification of water. Herein, palladium (Pd) coated ZnO/CuO based nanocomposite was prepared successfully by a hydrothermal method and the product was characterized by XRD, HRTEM, SEM, EDS, TGA, FTIR and XPS techniques. The resultant adsorbent demonstrated remarkable adsorption capacity in the removal of harmful arsenic from water, which was 91.96 and 96.36 mg/g for both As(III) and As(V) respectively. Moreover, the effect of various parameters like —OH concentration and metal precursor on the morphology of Pd@ZnO/CuO nanocomposite has been studied. Consequently, both As(III) and As(V) were found to be well agreed with Langmuir and Freundlich isotherms, which ensures their adsorption through ion exchange and electrostatic interaction. Additionally, the whole process of arsenic removal was carried out at pH 4‒9 in the presence of various minerals. Finally, the adsorbent was reused and presented satisfactory results over five cycles, which render it as the best candidate for the elimination of arsenic from natural and industrial water samples.

Hollow-Structured Microporous Organic Networks Adsorbents Enabled Specific and Sensitive Identification and Determination of Aflatoxins.

Aflatoxin (AFT) contamination, commonly in foods and grains with extremely low content while high toxicity, has caused serious economic and health problems worldwide. Now researchers are making an effort to develop nanomaterials with remarkable adsorption capacity for the identification, determination and regulation of AFT. Herein, we constructed a novel hollow-structured microporous organic networks (HMONs) material. On the basis of Fe3O4@MOF@MON, hydrofluoric acid (HF) was introduced to remove the transferable metal organic framework (MOF) to give hollow MON structures. Compared to the original Fe3O4@MOF@MON, HMON showed improved surface area and typical hollow cavities, thus increasing the adsorption capacity. More importantly, AFT is a hydrophobic substance, and our constructed HMON had a higher water contact angle, greatly enhancing the adsorption affinity. From that, the solid phase extraction (SPE-HPLC) method developed based on HMONs was applied to analyze four kinds of actual samples, with satisfied recoveries of 85–98%. This work provided a specific and sensitive method for the identification and determination of AFT in the food matrix and demonstrated the great potential of HMONs in the field of the identification and control of mycotoxins.

An efficient pH‐responsive kappa‐carrageenan/tamarind kernel powder hydrogel for the removal of brilliant green and rose bengal from aqueous solution

AbstractThe objective of this study was to develop an eco‐friendly, cost‐effective, and efficient adsorbent using kappa‐carrageenan (KCG) and tamarind kernel powder (TKP) based cross‐linked 3‐D network hydrogel. The equilibrium swelling capacity of 1429% was achieved by optimization studies. The KCG/TKP hydrogel was characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, energy dispersive spectroscopy, and thermogravimetric analysis. This hydrogel was employed for the efficient removal of brilliant green (BG) and rose bengal (RB) dye from wastewater. BG and RB were used as a cationic and anionic model dye, respectively. The adsorption capacity of model dyes on KCG/TKP was investigated under different parameters like dye concentration, pH, temperature, and adsorbent amount. With remarkable adsorption capacity, the hydrogel demonstrated a strong dependence on the pH of the medium. The kinetics, adsorption isotherm, thermodynamic studies, and reusability were investigated. The KCG/TKP hydrogel follows pseudo‐second‐order kinetics and the Langmuir isotherm model for the adsorption of both BG and RB model dyes. Spontaneity and exothermic behavior of the adsorption process were revealed by thermodynamic findings. At pH 9, the maximum adsorption capacity of BG was 840.33 mg g−1 while the maximum adsorption capacity of RB was 168.06 mg g−1 at pH 5.

Hierarchical nano-porous carbon from semi-coke via a MgO template preparation strategy for ONP adsorption

O-Nitrophenol(ONP) industrial wastewater causes serious harm to human body and aquatic environment. In this paper, we adopted a recycled MgO template preparation strategy to design series of semicoke derived hierarchical porous carbons. The prepared samples were characterized by N2 adsorption and desorption and scanning electron microscope. The analysis showed that the HPC-1 had a high specific surface area of 723.3m2/g with a huge pore volume of 1.64 cm3/g and exhibited remarkable adsorption capacity of 503.02 mg/g in batch adsorption test for ONP. Adsorption isotherms and adsorption kinetics revealed the adsorption mechanism of ONP molecules on HPCs surfaces, which followed the langmuir monolayer adsorption and pseudo-second-order kinetic. Furthermore, the HPC-1 exhibited good reusability and recycling performance, reflecting its great potential in practical application.

Versatile Strategy for the Preparation of Woody Biochar with Oxygen-Rich Groups and Enhanced Porosity for Highly Efficient Cr(VI) Removal.

Biochar is widely used to remove hexavalent chromium [Cr(VI)] from wastewater through adsorption, which is recognized as a facile, cost-efficient, and high-selectivity approach. In this study, a versatile strategy that combines delignification with subsequent carbonization and KOH activation is proposed to prepare a novel woody biochar from waste poplar sawdust. By virtue of the unique multilayered and honeycomb porous structure induced by delignification and activation processes, the resultant activated carbonized delignified wood (ACDW) exhibits a high specific surface area of 970.52 m2 g–1 with increasing meso- and micropores and abundant oxygen-containing functional groups. As a benign adsorbent for the uptake of Cr(VI) in wastewater, ACDW delivers a remarkable adsorption capacity of 294.86 mg g–1 in maximum, which is significantly superior to that of unmodified counterparts and other reported biochars. Besides, the adsorption behaviors fit better with the Langmuir isotherm, the pseudo-second-order kinetic model, and the adsorption diffusion model in batch experiments. Based on the results, we put forward the conceivable adsorption mechanism that the synergistic contributions of the capillary force, electrostatic attraction, chemical complexation, and reduction action facilitate the Cr(VI) capture by ACDW.

Investigating chromium Cr(VI) removal using imidazolium based ionic liquid-chitosan composite adsorptive film

In this study, we prepared a novel promising composite adsorptive film of chitosan modified with 1-butyl-3-methylimidazolium acetate (Chitosan-[BMIM][OAc]) to combine the unique features of ionic liquid into the biosorbent to remove Cr(VI) from contaminated water. The film was characterized through Fourier Transform Infrared Radiation (FT-IR) to ensure proper chemical modification. Batch adsorption studies were systematically conducted to study the effect of parameters like pH, adsorbent dosage, contact time, and the initial concentration of Cr(VI) ions as well as evaluate Cr(VI) removal efficiency. The composite adsorptive film exhibited excellent removal efficiency of almost 87% at optimum pH values (3) and adsorbent dosage (2 g/L). Furthermore, the composite film shows fast kinetics by achieving 87% efficiency within 60 min of contact time. A remarkable adsorption capacity of 125.63 mg/g based on Langmuir isotherm has been demonstrated from the results. After adsorption, FT-IR studies investigation revealed the involvement of OH and NH functional groups in adsorption through electrostatic attraction. The environmentally benign adsorbent synthesized from chitosan biopolymer and [BMIM][OAc] can potentially serve as an excellent adsorbent for Cr(VI) removal from water.

Functionalized dual modification of covalent organic framework for efficient and rapid trace heavy metals removal from drinking water

A key challenge in trace heavy metals removal from drinking water by adsorption technology is to achieve high adsorption capacity and rapid uptake speed of adsorbent. Herein, we report a functionalized double modified covalent organic framework (DMTD–COF–SH) bearing high-density sulfur and nitrogen chelating groups provided simultaneously by 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and 1,2-ethanedithiol, which was prepared via a facile one-pot thiol-ene “click” reaction. PXRD, FTIR, XPS, SEM, BET and 13C MAS NMR confirmed their successful graft, and DMTD was found to be more easily grafted on the COF surface layer than 1,2-ethanedithiol. The as-prepared DMTD–COF–SH showed remarkable adsorption capacity and ultrafast uptake dynamics to trace heavy metals owing to the synergistic effects resulting from densely populated sulfur and nitrogen chelating groups within ordered COF mesopores and at the COF surface. On the basis of the drinking water treatment units standard NSF/ANSI 53–2020, when the adsorbent dosage was 10 mg/30 mL and 20 mg L−1 calcium ions coexisted, the lead concentration decreased from initial 150 μg L−1 to 2.89 μg L−1 within 10 s, far below the allowable limit of world health organization (WHO) drinking water standard (10 μg L−1), and the maximum adsorption capacity meeting the standard attained 14.22 mg g−1. The adsorbent also exhibited excellent stability, wide applicable pH range and outstanding adsorption performance for coexisting trace lead, mercury, cadmium, chromium (VI) and copper in tap water, indicating that the DMTD–COF–SH material has excellent application prospect for trace heavy metals removal from drinking water.

A Membrane‐Supported Bifunctional Poly(amidoxime‐ethyleneimine) Network for Enhanced Uranium Extraction from Seawater and Wastewater

Uranium extraction from natural seawater and wastewater are quintessential requirements to supply uninterrupted carbon-free nuclear energy and to prevent potential radiochemical and toxicological effects, respectively. Owing to the complexity and low-concentration uranium of these water samples, the design and synthesis of sorbent materials for uranium extraction with meaningful efficiencies remains a grand challenge. Herein, we reported a novel three-dimensional bifunctional network of hyperbranched poly(amidoxime-ethyleneimine) (PAO-h-PEI) using PEI as the skeleton material via cyanoethylation, crosslinking and then amidoximation. As a result of the synergistic supramolecular strategy, the PAO-h-PEI membrane achieved a remarkable adsorption capacity of 985.7 mg/g for aqueous uranium solution, which was 2.5 folds that of the monofunctional h-PEI membrane (387.6 mg/g). The PAO-h-PEI membrane also exhibited good selectivity towards uranium in the presence of various metal ions, high-content salt, and natural organic matter as well as common anions. According to the XPS and FTIR results, the utilization of amines as the second ligand enhanced uranyl binding by providing additional coordination sites or by interacting with oxime to force N-OH dissociation. The good reusability (adsorption rate of 93% after six adsorption-desorption cycles) and satisfactory adsorption performance in extracting low-concentration uranium in real seawater demonstrate its practicability.

A Review on Removal of Heavy Metals from Water by Adsorption

Substantial contamination of heavy metals in drinking water has been an issue to consumers since long. The persisting contamination level has been monitored by various agencies and researchers, which direct towards constant deterioration of water quality. The quality of water is degrading exponentially from rural to urban areas in a significant manner. Industrial effluents, sewage and agricultural waste are the prime sources of contamination of water resources. Various heavy metals such as nickel, chromium, lead, arsenic, cadmium, mercury and copper may be present in industrial effluents. Though different methods such as chemical precipitation, ion exchange, membrane filtration, coagulation – flocculation and electro dialysis are known, amongst which adsorption being the most versatile and economically viable has been extensively adopted by various researchers for trace level of concentrations. In this review, several low cost adsorbents are reported in the literature have been studied at length. Different types of adsorbents like nanosorbent, biosorbents, carbonaceous material and metal based adsorbents have been considered for the review paper. The review paper evaluates the possibilities of utilizing various adsorbents for efficient removal of different heavy metals from water. Study reflected towards remarkable adsorption capacity, efficiency and cost effectiveness of adsorbents utilized by researchers. The boundless use of low cost adsorbents for treatment of wastewater are strongly recommended due to their availability,

Balancing the CO2 adsorption properties and the regeneration energy consumption via the functional molecular engineering hierarchical pore-interface structure

How to combine the green fabrication process of advanced materials with the engineering of microscope surface functionalization, simultaneously constructing the relationship between the micro-structure and macroscopic energy consumption from the molecular-level, is the significant issue for revealing the process energy consumption towards ultra-low emission flue gas CO2 storage in science-engineer field. Herein, following the research-line of ‘molecular interface structure → CO2 adsorption properties → regeneration energy consumption’, we facilely synthesized an amine-grafted hierarchical porous material (1,2-epoxyhexane (EH) modified Polyethyleneimine (PEI) grafted into glucose-based carbon sphere (GCS)), which presents excellent performance on CO2 adsorption and lower regeneration energy consumption. As for (EH modified PEI)-grafted glucose-based carbon sphere (EH@PEI-GCS), the strategy of increasing the effective amines ratio and reducing the pore blockage is helpful to construct a molecular-modified porous 3D-interface achieving a CO2 adsorption capacity of 5.34 mmol/g and a CO2/N2 (the ratio of Volume: 15%:85%) separation factor of 100.5 at 313 K and 1 bar. Impressively, compared with the different modified molecule configurations, the EH@PEI-GCS can dramatically improve the water resistance, thermal/cycle stability and lower the regeneration energy consumption, simultaneously without remarkable adsorption capacity losing. Comprehensively, it is critical to declare the relationship between the molecular-modified pore surface structure and regeneration energy consumption, and even to bridge the Micro-hierarchical materials science with Macro-energy engineer field.

Thiolated Polyethyleneimine-Based Polymer Sponge for Selective Removal of Hg2+ from Aqueous Solution.

Polymer sponges with molecular recognition provide a facile approach to water purification and industrial separation with easy operation. Herein, a thiolated polyethyleneimine (PEI)-based polymer sponge was prepared through cryo-polymerization of PEI, followed by grafting of PEI and then post-modification of the amine functionalities present within the hyperbranched structure with methyl mercaptoacetate, which afford high density of thiol functional groups on the surface of the sponge. The developed sponge was characterized by scanning electron microscopy and element analysis, and the adsorption kinetic and isotherm studies were conducted in detail. The sponge presents a remarkable maximum adsorption capacity of 2899.7 mg/g, which can be attributed to its high density of thiol functionalities. The sponge also shows excellent selectivity toward Hg2+ against other metal ions and natural organic matter, indicating its great potential in removing mercury from real water bodies. In addition, the sponge can be chemically regenerated and exhibits good reusability, which decreases the economic and environmental impacts. Hence, the high removal efficiency, high selectivity toward mercury, and good reusability of the sponge material highlight it as a promising sorbent for mercury removal in water pollution treatment.

Adsorption of fluoride and DB-53 dye onto PLA/rGO nanoparticles: Mathematical modeling and statistical studies

World Health Organization considered hazardous dye and fluoride removal to be an emergency issue in the water treatment process. In this investigation, fluoride and DB-53 dye adsorption was carried out using perovskite LaAlO3 (PLA) anchored with green synthesized rGO via the solvothermal process. BET characterization of PLA/rGO shows enhanced specific surface area (250 m2g−1) than PLA (5.91 m2g−1). PLA/rGO showed remarkable adsorption capacity of fluoride (qmax = 173.1 mgg−1) and DB-53 dye (qmax = 37.78 mgg−1) individually. The Fractal-like-pseudo-second order and Sips isotherm model well fitted with experimental statistical computation data R2 (1.000). The field water studies of fluoride removal and competing ions effect proved the novelty of the material. The potentiality of the PLA/rGO is proved by fluoride removal upto six effective cycles. Further, PLA/rGO exhibited high antibacterial properties compared to PLA because of their opposite electric charged nature of bacterial cell walls and surface charge of the nanocomposite. Hence, the present material study is multifunctional and interesting in the adsorption of fluoride and DB-53 dye with antibacterial properties.

Facile synthesis of DTC-Chm-GO nanocomposite with remarkable adsorption capacity and antibacterial activity

In this study, a novel dithiocarbamate functionalized magnetic chitosan graphene oxide (DTC-Chm-GO) nanocomposite was synthesized for the first time and used for simultaneously dyes and heavy metal ions adsorption as well as bacterial disinfection in complex wastewater. The maximum adsorption capacities of DTC-Chm-GO for the four pollutants calculated from Langmuir isotherm were 507.61, 520.83, 416.67, 349.65 mg·g−1 for methylene blue (MB), crystal violet (CV), Pb2+, Cu2+, respectively, which was attributed to the abundant functional groups on the surface of DTC-Chm-GO. Besides, the adsorption mechanism of MB was dependent on electrostatic interaction, π-π interaction and cation-π interaction, while Pb2+ removal mechanism could be related with electrostatic interaction and coordinate covalent bonds. In addition, the synthesized DTC-Chm-GO nanocomposite exhibited excellent antibacterial activity towards both E. coli and S. aureus. Thus, the DTC-Chm-GO could be an ideal candidate in environmental remediation, intelligent separation, bacterial inactivation and so on.

Waste eliminated by waste under COVID-19 pandemic: Mixed plastic waste derived N,O-rich porous carbon nano-coral reefs for chlorophenol pollutants efficient capture

Both increasing emission of chlorophenol chemicals and plastic waste pollution are severe global environmental challenges, which is worth being explored to respond with a "waste eliminated by waste" coupling treatment strategy. Herein, we propose a one-step recyclable nano-MgO template strategy to prepare in-situ N, O-doped novel porous carbon coral reefs (PCNCR) directly derived from the mixture of real waste PET and melamine formaldehyde resin. The template precursor can be conveniently recycled by facile acetic acid pickling, vacuum evaporation and drying, and the whole preparing process does not involve any toxic solvents, massive consumption of pore-forming agents, or discharge of salty wastewater. The obtained PCNCRs have hierarchical porous structures and abundant N, O-doped species, and the textural parameters can be modulation linearly by varying the mass ratio of magnesium acetate to mixed waste plastics. The optimized PCNCR-1.25 exhibited remarkable adsorption capacity for chlorophenol contaminants (777.5 mg/g for 4-Chloro-3,5-dimethylphenol, PCMX and 538.74 mg/g for 4-Chloro-3-methylphenol, PCMC) in aqueous solution. Adsorption isotherm fitting studies revealed chlorophenol contaminants tended to be rapidly adsorbed on the PCNCR surface in the form of monolayer. And the system reached adsorption equilibrium at about 15 min, which was described by linear driving force model. Reusability test verified that PCNCR-1.25 had excellent adsorption stability for chlorophenol in continuous adsorption-regeneration cycles. DFT calculation illustrated the enhancement of chlorophenol adsorption by heteroatom species, especially nitrogen dopants. This work highlighted a low-cost and sustainable approach to defuse the dual environmental threat of chlorophenol emissions and plastic waste pollution simultaneously.