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Two sodium alginate-based Pb2+-imprinted thermosensitive hydrogels (SPIT (without ɛ-PL) and SPPIT (with ɛ-PL)) were synthesized, with sodium alginate and ɛ-polylysine (ɛ-PL) as the matrix, N-isopropylacrylamide as the monomer. Characterization with differential scanning calorimeter, Fourier transform infrared spectroscopy, thermogravimetric analyzer, scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy confirmed the aimed structure of the hydrogels. The adsorption capacity of SPIT and SPPIT for Pb2+ was 98.64 mg/g and 153.49 mg/g, respectively. Washing the Pb2+-loaded adsorbent with 10 °C deionized water, SPIT and SPPIT achieved a desorption efficiency of 94.59 % and 97.51 %, respectively. After 10 cycles of adsorption-desorption process, the adsorption capacity and desorption efficiency remained at about 80–88 % of the original ones, expressing excellent reusability. In a mixture containing eight metal ions (Pb2+, Cu2+, Mg2+, Ca2+, Cd2+, Na+, K+, Fe3+), the adsorption capacity of SPIT to Pb2+ was 92.49 mg/g, and that of SPPIT was 102.49 mg/g, much higher than that to the other ions (1.50–11.38 mg/g on SPIT, 9.48–27.45 mg/g on SPPIT), showing excellent adsorption selectivity. The introduction of ɛ-PL enhanced the adsorption capacity, antibacterial ability and stability of the hydrogel, ensuring better application potential in real wastewater. • Two Pb2+-imprinted adsorbents were prepared with sodium alginate as the matrix. • The differential scanning calorimeter test confirmed the reversible thermosensitivity of the adsorbents. • Washing with cold water (5-10 °C) could regenerate the Pb2+-loaded adsorbents. • After 10 cycles of reuse, 80–88 % of the adsorption capacity was remained. • The adsorptive selectivity coefficient of adsorbent was up to 33.99. [ABSTRACT FROM AUTHOR]

The adsorption process of deionized water droplets on the parallel flow interface between ionic liquid [BMIM][PF6] and mineral oil is investigated in U-shaped microchannels. Three flow patterns of the efficient adsorption, moderate adsorption, and inefficient adsorption based on the adsorption efficiency were observed. The dimensionless droplet length D / W > 0.72 is conducive to efficient adsorption of droplets. When droplet shape factor β > 1, the lubrication pressure generated within the curved liquid film has a more significant hindrance on the adsorption process, and the reverse lubrication pressure at the outlet of the liquid film is the main reason for the rupture of the liquid film. An increase in the velocity of phase interface A-B movement can lead to an increase in lubrication pressure. A correlation model is established between the dimensionless adsorption length L * and the dimensionless adsorption time t *, and the influence of Laplace pressure is analyzed. [Display omitted] [ABSTRACT FROM AUTHOR]

2,4,6-trinitrophenol (TNP) has various industrial applications and is also extremely used by militaries and terrorists to make various explosives. Owing to their extensive industrial and military use and higher water solubility, their huge quantity is released into the environment and thus become a momentous environmental pollutant. TNP is highly toxic, poorly biodegradable, and a vigorous poison, strongly carcinogenic, and could cause severe diseases in humans and other animals. Thus, TNP present in the industrial wastewater and landfill leachate must be removed due to its detrimental effects on natural ecosystems. In the present review, the nature of TNP and its decontamination approaches are discussed, as well as their detailed mechanisms. The challenges that arise while applying TNP decontamination approaches were discussed and some future directions are highlighted for enhancing the efficiency of these approaches in a sustainable and friendly manner. [Display omitted] • Trinitrophenol (TNP) is a highly explosive and toxic pollutant, causing severe threats to human health and the environment. • Biodegradation, adsorption, photocatalytic degradation, and electrocatalytic degradation were employed to decontaminate TNP. • Incomplete biodegradation and secondary pollution generation in adsorption are the major challenges. • Photodegradation is a suitable treatment for complete remediation compared to conventional treatments. • Mechanistic understanding of the photodegradation of TNP via experimental and theoretical studies needs further exploration. [ABSTRACT FROM AUTHOR]

The efficiency of saturated Activated Carbon (AC) electrochemical regeneration was evaluated. Reactor configurations in cathodic/anodic process, applied current effect on the properties of AC and Methylene Blue MB-AC interactions and adsorption/desorption mechanisms were studied. The efficiency was measured by adsorption capacity adsorption/regeneration cycles and changes in the adsorbent characteristic were analyzed through FTIR, BET, Optical Microscopy (OM) and SEM before and after the regeneration. The energy consumption was analyzed to assess the economic feasibility. It was found that the electrochemical treatment was efficient in returning the AC adsorption capacity, maximum efficiencies of approximately 79% and 84% were reached when the Carbon Fiber Cloth-AC electrode was subjected to anodic and cathodic currents, respectively, at a current of 0.1 A. In addition, the material demonstrated good stability through adsorption-regeneration cycles by cathodic process, with the material's adsorption capacity being almost totally recovered for 8 consecutive cycles. The removal percentage around 80% was kept after the cycles, with optimal conditions when the electrode was subjected to cathodic currents, NaCI as electrolyte at a current of 0.1 A for 2 h. The characterization techniques provided results that allow to explain the higher and prolonged efficiency of the cathodic current. Furthermore, these reactor configurations achieved an electrical energy consumption of 2.3 and 2.1 kWh kg-1 of material for cathodic and anodic, respectively. These results indicate that the electrochemical is an economical and environmental suitable technique capable of restore carbon adsorbents to be reusable for several water treatment cycles. [ABSTRACT FROM AUTHOR]

Various magnetic carbon materials have been employed for nuclide adsorption, yet there exists a research gap concerning their application in electro-adsorption for nuclide removal. In this study, a magnetic carbon nanotube nanocomposite (Fe 3 O 4 /CNT) was successfully synthesized as an electrode material through the hydrothermal method, involving the modification of minute Fe 3 O 4 nanoparticles onto the surface of carbon nanotubes (CNT). Electrochemical assessments revealed that the Fe 3 O 4 /CNT nanocomposite exhibited a higher specific capacitance compared to Fe 3 O 4 and CNT individually. The HRTEM image reveals a heterojunction structure formed directly between Fe 3 O 4 and CNT, which facilitates electron transmission. The Fe 3 O 4 /CNT nanocomposite was utilized as an electrode in a capacitive deionization (CDI) device for U (VI)-contaminated wastewater purification. Experimental results demonstrated that the maximum U (VI) adsorption capacity of the Fe 3 O 4 /CNT electrode reached 287.53 mg/g at 298 K, and the adsorption process conformed to the Langmuir isotherm model. Kinetic analysis further indicated that the adsorption of U (VI) by Fe 3 O 4 /CNT followed a pseudo-second-order kinetic model. Additionally, the Fe 3 O 4 /CNT nanocomposite was transformed into a flowable electrode liquid and applied in a flow-electrode capacitive deionization (FCDI) system for U (VI) removal from aqueous solutions. Leveraging its superparamagnetic properties, the Fe 3 O 4 /CNT flow-electrode within the FCDI system could be rapidly recovered via a straightforward magnetic separation procedure. Notably, after nine consecutive runs of the FCDI device, the Fe 3 O 4 /CNT flow-electrode successfully concentrated a low-concentration U (VI) solution of 120 mg/L into a high-concentration solution of 1230 mg/L, thereby achieving the goal of water resource conservation and reduced storage requirements. [Display omitted] • The high-performance Fe 3 O 4 /CNT nanocomposite was prepared through a one-pot method. • The Fe 3 O 4 /CNT has a higher specific capacitance because of the synergistic effect. • The Fe 3 O 4 /CNT can be used as an electrode for CDI and FCDI devices to remove U (VI). • The Fe 3 O 4 /CNT flow-electrode can be quickly recovered by magnetic separation. [ABSTRACT FROM AUTHOR]

• The continuous adsorptive removal of phenol using low-cost activated carbon was studied. • Effects of electromagnetic field (EMF), and electric potential (EP) in the phenol removal were studied. • EMF enhanced the removal performance of activated carbon electrodes on the aluminum substrate. In this study, we introduce an electrode configuration setup to study the effect of an electromagnetic field (EMF) and electric potential (EP) on phenol removal in a continuous adsorption process. Feed water contaminated with dissolved phenol was exposed to EMF and passed through charged activated carbon electrodes prepared from Phoenix dactylifera (palm tree) biowaste. This study investigated the effects of magnetic field exposure, electric potential, feed salinity, and electrode substrate type. The results revealed that the highest adsorption uptake capacity of 47.2 mg/g was achieved using an aluminum substrate (AS) with EMF at zero salinity. The phenol adsorption kinetics followed a pseudo-second-order adsorption rate and diffusion model, indicating that intraparticle diffusion was the primary rate-limiting mechanism. The increased phenol adsorption uptake capacity brought on by the EMF may result from the improved mass transfer and mobility of the adsorbate and, consequently, the increased effectiveness of the internal diffusion of the pollutants. Finally, a regeneration efficiency of 99 % was achieved using NaOH at a salinity of 5,000 ppm. [ABSTRACT FROM AUTHOR]

[Display omitted] • The leaching effect of albite was sorted as follows: hydrochloric acid > potassium hydroxide > deionized water. • The adsorption of H 3 O+, OH− and H 2 O molecules on the surface of albite resulted in the loose framework of albite. • The H+ and K+ in solution exchanged with Na+ in albite and caused the leaching of Na element in albite. The mechanism of inorganic acid and alkali promoted weathering of albite is still unclear. In this work, the mechanism was investigated through leaching experiments and DFT simulations. The results showed that the leaching effect of albite was sorted as follows: hydrochloric acid > potassium hydroxide > deionized water. The H 3 O+ dehydrogenated by breakage of O–H bond, and then the proton bonded with the O atom to form a silicon hydroxyl group on the surface of albite. The O atom in OH− bonded with the three-coordinated Al atom to form the four-coordinated Al. The H 2 O molecule was adsorbed on the surface of albite by hydrogen bond. Meanwhile, the adsorption of H 3 O+, OH− and H 2 O on the (0 0 1) surface of albite caused the elongation of Si–O and Al–O bonds in the bulk phase, resulting in the loose framework of albite. Compared to the interaction mode of water molecules and albite, the H+ in hydrochloric acid and K+ in potassium hydroxide exchanged with Na+ in albite, which caused that the albite lattice was contracted and expanded, respectively. As a result, the surface of albite was damaged, and further caused the Na element was released from the albite crystal to liquid phase. [ABSTRACT FROM AUTHOR]

The adsorption phenomenon on surfaces is investigated both with and without the presence of an external electric field. A simple interpretation of the adsorption coefficient and desorption time, as they appear in Langmuir's isotherm model, is presented. A model for electrosorption is proposed, which explicitly takes into account the applied external voltage and the reaction field resulting from the adsorbed charges. Both saturation, stemming from the finite density of adsorption sites, and non-saturation regimes are considered. The case of a system in contact with a reservoir of particles is also analyzed for its experimental importance. The model's validity is assessed by analyzing experimental data published by several research groups. A comparative study of the proposed model is conducted in relation to the commonly used pseudo-first and pseudo-second order models. Unlike the latter models, the proposed model allows for the assessment of the impact of the external voltage on the model parameters. The model takes into account ion generation resulting from electrolysis phenomena. [Display omitted] [ABSTRACT FROM AUTHOR]

Bioelectrochemical system is a prospective strategy in organic-contaminated groundwater treatment, while few studies clearly distinguish the mechanisms of adsorption or biodegradation in this process, especially when dense biofilm is formed. This study employed a single chamber microbial electrolysis cell (MEC) with two three-dimensional electrodes for removing a typical organic contaminant, 2,4-dichlorophenol (DCP) from groundwater, which inoculated with anaerobic bacteria derived from sewage treatment plant. Compared with the single biodegradation system without electrodes, the three-dimensional electrodes with a high surface enabled an increase of alpha diversity of the microbial community (increased by 52.6% in Shannon index), and provided adaptive ecological niche for more bacteria. The application of weak voltage (0.6 V) furtherly optimized the microbial community structure, and promoted the aggregation of microorganisms with the formation of dense biofilm. Desorption experiment proved that the contaminants were removed from the groundwater mainly via adsorption by the biofilm rather than biodegradation, and compared with the reactor without electricity, the bioelectrochemical system increased the adsorption capacity from 50.0% to 74.5%. The aggregated bacteria on the surface of electrodes were mainly dominated by Delftia tsuruhatensis (85.0%), which could secrete extracellular polymers and has a high adsorption capacity (0.30 mg/g electrode material) for the contaminants. We found that a bioelectrochemical system with a three-dimensional electrode could stimulate the formation of dense biofilm and remove the organic contaminants as well as their possible more toxic degradation intermediates via adsorption. This study provides important guidance for applying bioelectrochemical system in groundwater or wastewater treatment. [Display omitted] • Bioelectrochemical system was used to treat chlorophenol-contaminated groundwater • External electricity led to the aggregated biofilm on three-dimensional electrode • The dense biofilm enhanced the adsorption of chlorophenols from 50% to 74.5% • The aggregations on electrode were dominated by Delftia tsuruhatensis (85%) • Delftia tsuruhatensis was enriched for the first time in bioelectrochemical system [ABSTRACT FROM AUTHOR]

• Aggregates swell due to the "adsorption-swelling" and "adsorption-filling" effects. • The "adsorption-swelling" effect was most prominent with fraction size 2 ∼ 1 mm. • The "adsorption-filling" effect was most prominent with fraction size < 0.053 mm. Soil aggregates swell when infiltrated by water, and their size can increase in two ways. First, aggregates can attach to one another with water acting as a bridge (i.e., adsorption), and water can enter the aggregate pores (i.e., swelling). This is defined as the "adsorption-swelling" effect. Second, clay can fill the pores of macroaggregates and microaggregates (i.e., filling) when adsorption occurs. This is defined as the "adsorption-filling" effect. However, the size range of aggregates affected by these effects and the extent of their influence on aggregate swelling are still unclear. Therefore, different initial size fractions (5 ∼ 2, 2 ∼ 1, 1 ∼ 0.5, 0.5 ∼ 0.25 and 0.25 ∼ 0.053 mm) of soil aggregates from the black soil zone of Northeast China were studied. The size range of swollen aggregates, the "adsorption-swelling" rate (V) of initial size fractions, and the "adsorption-filling" rate (E) of size fractions < 0.053 mm were measured and calculated in three experimental treatments that involved the following procedures: i) wet-sieving of each initial size fraction in deionized water (WS); ii) wet-sieving of each initial size fraction of air-dried aggregates after they were soaked in absolute ethanol (WS as); and iii) the size fraction < 0.053 mm air-dried aggregates were mixed with each initial size fraction of air-dried aggregates in absolute ethanol and then wet-sieved (WS af). The results were as follows: i) the size fraction 2 ∼ 0.053 mm were swollen. ii) V decreased exponentially with decreasing initial particle size, with a maximum value of 32.30% at a size fraction of 2 ∼ 1 mm; and iii) the "adsorption-filling" effect of size fraction < 0.053 mm was obvious in the size fraction < 2 mm swelling aggregates with a maximum of 29.54%. The "adsorption-swelling" and "adsorption-filling" effects had greater impacts on soils with high contents of the size fractions 2 ∼ 1 and < 0.053 mm. This study provides a theoretical basis for understanding the swelling mechanisms of soil aggregates. [ABSTRACT FROM AUTHOR]

Selective capture of radioactive 99TcO 4 - from highly alkaline nuclear waste is highly desirable for environmental remediation and waste disposal. However, the combined features of adsorbents with excellent chemical stability and high capture selectivity for 99TcO 4 - have not yet been achieved. Herein, we report an ultra-stable 3D pyridinium salt-based polymeric network (TMP-TBPM) nanotrap with remarkable radiation, acid and base stability for selective capture of ReO 4 - via hydrophobic engineering and steric hindrance, a non-radioactive surrogate of 99TcO 4 -. The batch capture experiments show that TMP-TBPM has high capture capacity (918.7 mg g−1) and fast sorption kinetics (94.3 % removal in 2 min), which can be attributed to the high density of pyridinium salt-based units on the highly accessible pore channels of 3D interconnected low-density skeleton. In addition, the introduction of abundant alkyl and tetraphenylmethane units into the 3D framework not only greatly enhanced the hydrophobicity and stability of TMP-TBPM, but also significantly improved the affinity toward 99TcO 4 -/ReO 4 -, enabling reversible and selective capture of 99TcO 4 -/ReO 4 - even under highly alkaline conditions. This study exhibits the great potential of 3D pyridinium salt-based polymeric network nanotrap for 99TcO 4 -/ReO 4 - capture from highly alkaline nuclear waste, providing a new strategy to construct high-performance cationic polymeric sorbents for radioactive wastewater treatment. [Display omitted] • Robust 3D pyridinium salt-based polymeric network for selective capture of ReO 4 −. • The first example of 3D pyridinium salt-based polymeric network for ReO 4 - capture. • TMP-TBPM has excellent capture performance and high selectivity for 99TcO 4 -/ReO 4 -. • TMP-TBPM can selectively and reversibly capture 99TcO 4 -/ReO 4 - under alkaline conditions. [ABSTRACT FROM AUTHOR]

Polysaccharide-based hydrogel adsorbents become popular because of their high adsorption capacity and fast adsorption rate, but their low removal rate and poor pH resistance have always been fatal shortcomings. Herein, a feasible strategy was proposed to strengthen the ability of hydrogel adsorbent to remove organic pollutants (i.e., dye) by incorporating natural rectorite (REC) into chitosan- g -poly (2-acrylamido-2-methyl-propane-sulfonic-acid) hydrogel network to form a rectorite-in-polymer network structure. The introduction of less dosage of REC (1.2 wt%) into the hydrogel facilitates to improve its adsorption capacities toward methylene blue (MB) in deionized water, tap water, seawater, Yangtze River water, and Yellow River water (1083.39–1303.49 mg/g); while incorporating higher content of REC (15.8 wt% REC) helps to improve the removal rate (99.6% for MB in real waters), which are greatly superior to commercial activated carbons. The adsorbent keeps high adsorption efficiency in a broad pH range (2–11), and can be reused for >4 times. [Display omitted] • Synthesized chitosan-based hydrogel has a rectorite-in-polymer composite network. • The hydrogel shows high adsorption capacity (1303.49 mg/g) and removal rate (99.6 %). • Removal efficiency keeps high in real waters (Yangtze River, Yellow River, seawater). • The hydrogel's adsorption capacity far exceeds that of commercial activated carbon. • This method is universal to enhance the removal efficiency of hydrogel adsorbent. [ABSTRACT FROM AUTHOR]

• WO 3 –WS 2 decorated polypyrrole nanocomposite are investigated for removing heavy metals and supercapacitor application. • Compared to WO 3 –WS 2 and PPy, WO 3 –WS 2 /PPy showed superior heavy metal removal efficiency. • WO 3 -WS 2 /PPy based electrodes exhibit remarkable supercapacitive properties. • Even after 5000 cycles, WO 3 -WS 2 /PPy exhibits outstanding stability and capacity retention of 81%. Nowadays, developing a simple, economic, and scalable approach for environmental remediation and producing energy storage devices remains challenging. Herein, we report a novel WO 3 –WS 2 decorated polypyrrole (WO 3 –WS 2 /PPy) nanocomposite for the removal of heavy metals, i.e., Cd(II) and Ni(II) and high-performance supercapacitor electrodes. The WO 3 –WS 2 /PPy showed significant improvement in the removal of Cd(II) (95.33%) and Ni(II) (89.95%), while WO 3 –WS 2 and PPy revealed removal efficiency of 87.02 and 77.01% for Cd(II) and 82.97 and 74.66% for Ni(II), respectively. For the competitive adsorption experiment, Cu2+/Zn2+ causes a significant influence, while Na+/K+/Mg2+/Ca2+ exerted less effect on the adsorption of the aforementioned metal ions. The WO 3 –WS 2 /PPy exhibited higher selectivity toward Cd2+ than Ni2+. Along with, the WO 3 –WS 2 decorated PPy based electrode showed a high specific surface area and support conductive networks, which synergistically improved charge storage capability. The WO 3 -WS 2 /PPy-based electrodes exhibit superior electrochemical performance with excellent rate capability, offering the high specific capacitance value of 624 F/g at 3 A/g current density and retaining capacitance stability of 81% after 5000 cycles in 1 M Na 2 SO 4 electrolyte solution. The outcomes of this research infer that WO 3 -WS 2 /PPy is a promising candidate for wastewater treatment and high-performance energy storage applications. [ABSTRACT FROM AUTHOR]

The extensive application of copper in numerous industries leads to its accumulation in the environment, imposing severe toxic and carcinogenic health effects to human. In this article, the recent advances of abatement technologies for copper containing industrial wastewater were reviewed, including adsorption, electrochemical, and precipitation/crystallization processes. Adsorption is effective in treating dilute copper wastewater. Several adsorbents derived from biomass and clay have been developed, as well as the nano-sized and composite adsorbents. Electrochemical treatments such as electrodialysis, electrocoagulation, and capacitive deionization are also in demand due to its versatility, minimal use of chemical reagents, and compact design. Precipitation and crystallization techniques, including the emerging fluidized bed homogeneous crystallization process, are improved not only to provide effective removal but also to recover copper as sparingly soluble salts which can be further utilized for other industrial and scientific purposes. The abatement technologies for Cu(II) were compared to provide guidelines for the selection of processes based on the characteristics of wastewater. Ultimately, the limitation of the processes was summarized to reveal the perspectives in future research. [Display omitted] • Adsorbents are based on clay, metal oxide and carbons with functionalization. • Principle, advantage and limitation of electrochemical methods were reviewed. • Fluidized-bed crystallization was included in precipitation approach. • The majority of the reference is within the past five years. [ABSTRACT FROM AUTHOR]

A three-dimensional electrode reactor (3DER) was developed and evaluated for the degradation of recalcitrant pharmaceutical compounds such as diclofenac (DCF) and acetylsalicylic acid (ASA) from water, using for the first-time activated carbon monoliths (AC m) fabricated by 3D printing as a third electrode in the oxidation process. The degradation and mineralization percentages for the 3DER system were 81% and 74% respectively, which was up to 2.5 times higher than the system without using a third electrode. On the other hand, synergy calculations were performed, obtaining values of up to 35% when the integrated adsorption-oxidation technology was used compared to the degradations obtained by both processes sequentially. Operating parameters such as initial AC m saturation time (60 and 240 min) and applied voltage (0.6 and 0.9 V) were evaluated. Kinetic constants (k app) were 3.2 times larger when the saturation time was shorter and the voltage higher. In addition, AC m regeneration tests were carried out to evaluate the regeneration of the material during the process, obtaining regenerations of up to 99%. Finally, the energy consumption by order of magnitude (EEO) was calculated for the best operating conditions in the 3DER, obtaining a value of 2.06 kWh/m3, which implies 50% less energy than the system without AC m. Despite the challenges in understanding the integrated processes in adsorption-electrooxidation, this study proposes compact and well-structured structures as an alternative for process optimization in 3DER. [Display omitted] • Adsorption-Electrooxidation with 3D printed structures is studied for the first time. • The efficiency increases with introducing a third electrode in the electrochemical reactor. • Best degradations are obtained at higher voltages and low initial adsorption times. • Energy consumption was lower with the adsorption-electrooxidation integrated process. [ABSTRACT FROM AUTHOR]

The availability and accessibility of clean and secure water supplies are pressing technological and scientific issues worldwide. As a result of global water constraints, wastewater treatment and reuse are being evaluated as feasible alternatives to fresh water for agricultural irrigation and domestic and industrial purposes. Boron carbon nitride (BCN) nanosheets have been studied intensively in the last decade in batteries, biosensors, and capacitors, and for use as catalysts, and they have recently been used in wastewater treatment. BCN materials, along with their synthesis processes, characteristics, and application areas in water and wastewater treatment, are discussed thoroughly in this paper. Additionally, synthesis processes for ternary BCN compounds, including chemical vapor deposition, ion beam-aided deposition, magnetron sputtering, and pulsed laser deposition, are described. BCN materials have also been explored because of their flexible electrical features, excellent mechanical strength, outstanding unreactivity, and significant stability, which make them appropriate for a range of severe environment applications. Thus, the use of BCN materials as photocatalysts and adsorbents and in electrochemical reduction and capacitive deionization are also discussed thoroughly. The highest ammonia production of 172,226.5 μg/h.mg.cat and faradic efficiency of 95.3% have been obtained using the BCN@Cu/CNT catalyst, whereas the ammonia production and FE values for metal-free BCN are 7.75 μg/h.mg.cat and 13.8%. Moreover, the maximum attained adsorption capacities of BCN nanosheets for Pb2+ and Hg2+ are 210 and 625 mg/g, respectively. Overall, this review indicates that essential work on BCN nanosheets is still needed. Future research should focus on the development of BCN nanostructures to encourage multidisciplinary research. [Display omitted] • BCN nanosheets improved performance for water treatment is summarized. • Synthesis methods for ternary BCN nanosheets are explored. • BCN as photocatalysts, adsorbents, and in electrochemical reduction are discussed. • Metal-loaded BCN nanosheets were elaborated as effective water treatment strategy. • Metal and ammonia production potential of BCN increased with metal modification. [ABSTRACT FROM AUTHOR]

• CPPS-2-18 electrode is fabricated by adsorbing the redox mediator(AR18) into the nanopores of CPPS-2 through electrosorption. • AR18 confined into the nanopores can play crucial role on enhancing the electrochemical properties of CPPS-2-18. • Due to the confined effect, the shuttle behavior of the ions in the electrolyte is inhabited well. • The electrochemical properties of the electrode are improved by confining AR18 into the nanopores. The limitation of low energy density of carbon-based supercapacitors can be broken through introducing redox mediators into the electrolyte. Herein, biomass porous carbon CPPS-2 with a high specific surface area of 1649 m2/g was prepared by KOH activation. Capitalizing on the adsorption property of porous carbon, redox mediator, acid red 18 (AR18), was confined into the nanopores of CPPS-2 to fabricate the CPPS-2-18 electrode. After adsorbing 2.72 mg AR18, the specific capacitance of CPPS-2-18 is 568F/g at a current density of 1 A/g in 1 M H 2 SO 4 , which is as same as that of CPPS-2 in 1 M H 2 SO 4 + 10 mM AR18, however, the rate performance and coulombic efficiency of CPPS-2-18 are higher than those of CPPS-2. The results reveal that the redox reaction in nanopores of CPPS-2-18 is more reversible than that on the surface of CPPS-2. Meanwhile, the symmetric supercapacitor based on CPPS-2-18 achieves a maximum energy density of 23Wh/kg and power density of 6000 W/kg. Besides, the self-discharging behavior of CPPS-2 is restrained by confining AR18 into the nanopores. [ABSTRACT FROM AUTHOR]

• A porous nanofiber membrane with dense distribution of La nanorods was prepared. • Exceptional high utilization ratio of La (0.98). • LPS was easily separated from solution. • The LPS can reduce total phosphorus to less than 10 μg/L in natural lake water. • Phosphate was effectively captured in a wide pH range of 4–10. As phosphate is one of the key causes of water eutrophication, its removal from aquatic ecosystems is essential. Adsorption methods have been widely used to remove phosphate from water bodies. However, most of the adsorbents are unstable and difficult to separate from solution. In this paper, we used a simple electrospinning method to prepare a new, well-dispersed, lanthanum (La)-based porous polyacrylonitrile nanofiber (LPS) with more active sites, which improve its phosphate removal efficiency. The maximum phosphate adsorption capacity on LPS was 218.5 mg P/g (La) (50.4 mg P/g). After complete adsorption, the P/La molar ratio on LPS was 0.98. After 48 h of oscillation, the leakage of La from LPS in deionized water was only 74 μg/L, effectively ruling out secondary pollution of the water-body. Moreover, unlike most adsorbents, LPS has the advantage that it can be readily isolated from water. After treatment with LPS, the total phosphorus (TP) of a water sample from Yangzonghai Lake (Yunnan, China) was reduced to 4.2 μg/L, a value lower than the concentration threshold of eutrophication (10 μg/L) set by the United States Environmental Protection Agency (USEPA) and the first category of the surface water environmental quality standard (10 μg/L) set by China for lakes and reservoirs. [ABSTRACT FROM AUTHOR]

[Display omitted] • CDI technology effectively removed Pb2+ from slightly-polluted water. • The doping of NCDs improved the structural and electrochemical properties. • A monolithic mesh electrode was prepared by electrospinning method. • The Langmuir isotherm and the pseudo-first-order model fitted the electrosorption. • The hydrated radius and valence affected the order of ion adsorption. Capacitive deionization (CDI) technology is an effective method for the removal of Pb2+ from slightly-polluted water. In this study, reduced graphene oxide/nitrogen-doped carbon quantum dots (rGO/NCDs) composites with different NCDs mass ratios were successfully synthesized by hydrothermal method and the preparation process of CDI electrode was optimized by electrospinning method to obtain monolithic mesh-like structure. The results showed that the doping of NCDs improved the structural and electrochemical properties of the composites. rGO/25%NCDs composite possessed well-developed three-dimensional porous structure, high specific surface area (347.65 m2/g) and excellent specific capacitance (284.0 F/g). The prepared CDI electrodes had a fish scale-like graded interfacial structure, and this unique structure made the electrodes exhibit superhydrophilic property. The results of CDI tests showed that the electrosorption capacity of rGO/25%NCDs electrode could reach 19.26 mg/g which was higher than that of the pure rGO electrode and many reported electrodes, when the initial concentration of Pb2+ was 5 mg/L and the voltage was −1.0 V. The adsorption process was consistent with the Langmuir adsorption isotherm and the pseudo-first-order kinetic model. In addition, the study on the competitive adsorption in a co-existed system revealed that the electrosorption capacity was strongly dependent on the ionic valence rather than hydrated radius. [ABSTRACT FROM AUTHOR]

In this study, adsorption of a non-steroidal anti-inflammatory drug such as Diclofenac (DCF) on a commercial carbonaceous aerogel honeycomb monolith (NANOLIT®-NQ40) was ascertained. Based on, the overall design of an adsorption treatment should include a feasible regeneration process for the spent adsorbent. In this work, the adsorption/desorption process was ameliorated by coupling of electrochemical technology (anodic/cathodic polarisation). It was determined that the anodic polarisation enhanced the DCF removal and it was related with the applied voltage and the disposition of the electrodes into the bulk solution. Anodic polarisation at optimal conditions (voltage 0.9 V, electrodes gap 2.5 cm and electrolyte concentration higher than 1 mM) provoked an enhancement (around 30%) in the DCF adsorption rate. The spent aerogel regeneration method for the adsorbed or electro-adsorbed DCF was investigated and cathodic polarisation proved to be a viable regeneration alternative attaining the total regeneration of aerogel. The electro-desorption mechanism seemed to be linked to the generation of repulsive intermolecular forces in the aerogel surface. Finally, the sequential electro-adsorption/electro-desorption process was performed in successive cycles. The results confirmed the feasibility of this strategy, maintaining the efficiency with no structural changes in the monolith after several cycles being the electro-reversible adsorption of pollutants on aerogel a promising technology for the removal of pharmaceuticals from wastewater. [Display omitted] • Removal of Diclofenac (DCF) by adsorption on carbonaceous aerogel honeycomb monolith. • Amelioration of adsorption/desorption process of DCF by anodic/cathodic polarisation. • Optimization of DCF electro-adsorption process: electrode gap, electrolyte, voltage. • Successful sequential electro-adsorption/desorption cycles and monolith regeneration. [ABSTRACT FROM AUTHOR]