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The heteroatoms and transition metal co-doped carbon-based catalysts are an important way to improve the catalytic activity of oxygen reduction reaction (ORR). Herein, we reported a facile method to obtain iron, nitrogen, and sulfur co-doped cellulose paper carbon fibers as catalysts (Fe–N–S/CFs) for ORR in microbial fuel cells (MFCs) with the adsorption recovery of Congo red molecules from dye wastewater. The thermal treatment promoted the etching of carbon surface by ferric ions, resulting in increased surface roughness for forming the defective carbon structure. The rich active species and defective carbon formed on the etched surface to enhance the electroactive surface area and effective sites. Fe–N–S/CFs catalysts achieved high half-wave potential due to the synergy effect between chemical components and defect structures. The assembled single-chamber air cathode MFC gained a high maximum power density of 1773 ± 40 mW m−2 versus Pt/C MFC of 1325 ± 94 mW m−2. This work provides a strategy for recovering dye molecules from wastewater to prepare non-precious metal catalysts for enhancing ORR activity. • Mg(OH) 2 @PF was employed to efficiently adsorb Congo red from the dye wastewater. • Congo red/Mg(OH) 2 @PF co-calcined with iron nitrate to fabricate Fe–N–S/FCs catalyst. • The Fe–N–S/CFs showed the excellent ORR performance with the active specie of FeN x. • The assembled air cathode MFCs achieved high maximum power density (1773 ± 40 mW m−2). [ABSTRACT FROM AUTHOR]

The pulp and paper industry consumes a huge amount of water and releases more polluted and colored wastewater every year. Many conventional techniques are used in the treatment of paper industry wastewater. However, for color removal from paper mill effluent, there is no proven method so far, on an industrial scale. Due to high energy input and high cost, there is an urgent need to find out a new technique that must be sustainable, economical, and environment friendly. Various methods have been investigated on bench scale and pilot scale also but no proven method for color removal on an industrial scale. The paper provides an overview of the color removal techniques from different sources of pulp and paper mill wastewater discharged by various industries. The review described various components involved in various processes for color removal from paper mill waste water. The present works focus on processes like chemical, chemical/physical, biological, physicochemical, and electrochemical applied in color removal from paper mill wastewater. The present review gives key information on the effectiveness, use, betterment, and limitations of numerous methods of treatment targeted at color removal from paper mill wastewater using various techniques still under evolution. • A critical study made on color removal from paper mill effluent using various methods. • Examined color removal efficiencies using conventional and advanced techniques. • Study on Cost analysis in color removal from paper mill effluent. • Future research suggestions described for better implementation of the processes. [ABSTRACT FROM AUTHOR]

Environmental pollution poses a major problem now a day. Several dyes, in the form of industrial waste, pollute water body and may cause adverse effects to human health. In this paper ADME and toxicity of fives Phenothiazinium group of dyes Methylene blue (MB), Azure A (AA), Azure B (AB), Azure C (AC) and Toluidine Blue O (TBO) were predicted using Swiss ADME and Protox II tools. Results showed these dyes may herm for living organism due to their carcinogenic, mutagenic and hepatotoxic properties. Removal efficiency of these dyes using okra plant product were determined using spectroscopic, thermodynamic and molecular modeling study. It was revealed that these dyes adsorb on the surface of okra leaf mostly at pH 7.0 and the adsorption isotherms were found to fit in Langmuir and Freundlich isotherm model, while Temkin model fails to do this. Mucilage present in different parts of okra plant plays a significant role on removal of these dyes and is able to remove near about 71–92 % of dyes from water body by itself. As this process did not fit in any of above said adsorption isotherm model, it may be suggested that some other mechanism may happen. Further studies explore that these dyes bound to the hydrophobic pocket of mucilage with binding affinity in the order of 105 M−1 and the bindings were exothermic in nature with enthalpy change in the range of − 2.94 to − 4.28 kcal/mole. Molecular docking study validate all the experimental results obtained from spectroscopic and thermodynamic study and enlighten the role of structure of dyes on their binding affinity to mucilage. This paper will help to systematically understand the role of okra plant products on removal efficiency of Phenothiazinium group of dyes with their structural variations. [Display omitted] • Swiss ADME and Protox II showed phenothiazinium group of dyes may be hazardous to human health. • These dyes can be removed from water body using okra plant product and the optimum pH of removal is 7.0. • Dyes adsorb on okra leaf and the adsorption fit to Langmuir, and Freundlich model. • Removal of dyes using okra plant product follow pseudo 1st order kinetics. • The dyes can bound to mucilage through exothermic reaction process, and the binding controlled by overall structure of dyes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pore opening-induced pore blocking is the mechanism for the limit to LCP. • LCP is described for desorption of condensate from closed cavities with wedge-like opening. • Experimental LCP for carbons at P/P 0 ∼ 0.4 is reproduced in simulations at boiling points. • Experimental LCP for silica at P/P 0 ∼ 0.5 is described correctly in simulations. • LCP is relatively insensitive to the geometrical aspects of the cavity. The limit to the lower closure point (LCP) observed experimentally in the desorption isotherm of gases in porous solids has been commonly attributed to the homogeneous cavitation of the condensate in cavities. It was proposed recently that the experimental limit to LCP could be described in simulations with the ink-bottle pore, provided that the length of the uniformly sized conduit connecting the closed cavity to the surrounding is shorter than 2 nm, and the evaporation is by way of pore blocking mechanism, rather than homogeneous cavitation. To substantiate this assertion, that deviates from the commonly belief of homogeneous cavitation, we further investigated in this paper with cavities having wedge-like pore opening , that better mimics real solids, and offer further explanation on the limit of the LCP to the pore blocking as the mechanism of evaporation with simulations of argon and nitrogen adsorption over a range of temperatures that are commonly used experimentally. It was found that simulation results correctly captured the experimental observations for carbon-based materials and silica-based materials in that the limit of LCP shifts to higher reduced pressures for weaker adsorbing silica, compared to stronger adsorbing carbon and for a given adsorbent it also shifts to higher reduced pressure for higher temperatures. [ABSTRACT FROM AUTHOR]

Although studies dealing with adsorption/desorption (and/or retention/release) of pollutants present in environmental compartments is a classical field of research, recent papers are focusing on some weak points of investigations and publications within the area. In addition, an increasing number of works are being published related to new possibilities and alternatives in this kind of research works, many of them in relation to the use of artificial intelligence (AI). Considering the existence of eventual controversies, eventual mistakes, and the convenience of suggesting alternatives to go ahead in the future, in this work, after taking into account some relevant publications in the previous literature, a simple workflow is proposed as a kind of protocol to revise successive steps that could guide the direction to follow when programing research dealing with the retention/release of pollutants in soils and sorbent materials. [Display omitted] • Recent papers show weak points of publications on pollutants adsorption/desorption. • Increasing works on the use of artificial intelligence in this kind of research. • A protocol is proposed to guide programing research on pollutants retention/release. [ABSTRACT FROM AUTHOR]

[Display omitted] Owing to the numerous potential applications of ZnO nanomaterials, the development of ZnO-based nanocomposites has become of great scientific interest in various fields. In this paper, we are reporting the fabrication of a series of ZnO/C nanocomposites through a simple "one-pot" calcination method under three different temperatures, 500 ℃, 600 ℃, and 700 ℃, with samples labeled as ZnO/C-500, -600, and -700, respectively. All samples exhibited adsorption capabilities and photon-activated catalytic and antibacterial properties, with the ZnO/C-700 sample showing superior performance among the three. The carbonaceous material in ZnO/C is key to expanding the optical absorption range and improving the charge separation efficiency of ZnO. The remarkable adsorption property of the ZnO/C-700 sample was demonstrated using Congo red dye, and is credited to its good hydrophilicity. It was also found to exhibit the most notable photocatalysis effect due to its high charge transfer efficiency. The hydrophilic ZnO/C-700 sample was also examined for antibacterial effects both in vitro (against Escherichia coli and Staphylococcus aureus) and in vivo (against MSRA-infected rat wound model), and it was observed to exhibit synergistic killing performance under visible-light irradiation. A possible cleaning mechanism is proposed on the basis of our experimental results. Overall, this work presents a facile way of synthesizing ZnO/C nanocomposites with outstanding adsorption, photocatalysis, and antibacterial properties for the efficient treatment of organic and bacterial contaminants in wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed micelles of cationic and non-ionic surfactants were studied in aqueous solution. • Mixed surfactant-modified zeolite (MSMZ) and SMZ were prepared and characterized. • The adsorption capacity of MSMZ for removal of DFS was higher than that of SMZ. • The experimental adsorption data of DFS by SMZ was correlated by Sips model. • The removal of DFS on MSMZ was strongly dependent on positive surface charge on zeolite. In this paper, the surfactant-modified clinoptilolite zeolite (with two methods) were used to remove diclofenac sodium (DFS) as a widely used drug in an aqueous solution. Clinoptilolite was modified by using pure cationic surfactant (cetyltrimethylammonium chloride, CTAC) and the mixed surfactants of CTAC + Triton-X100 (TX100). In the new approach, the synergistic effects between CTAC and TX100 were determined by surface tension measurements in different mole fractions and the optimum ratio (y 1 ≈ 0.8) was identified with the maximum synergism. According to the mole fraction of this composition, the surface of clinoptilolite was modified by mixed surfactants (MSMZ) for the adsorption of DFS and then results compared with modified zeolite with pure cationic surfactant (SMZ). The raw and modified (SMZ and MSMZ) zeolites were characterized by Fourier transform infrared spectroscopy (FT–IR), BET analysis, the scanning electron microscopy (SEM) images, Zeta potential and X-ray. The experimental data of adsorption in equilibrium conditions were also analyzed using different adsorption isotherm models (Langmuir, Freundlich, Hill, Khan, Sips, Redlich-Peterson and Toth) in non-linear forms, and finally, the best model consistent with experimental data is determined (SMZ:Sips and MSMZ:Toth). According to the best isotherm model, the amount of absorption capacity in MSMZ was obtained almost 57% higher than SMZ. In addition, the kinetic adsorption data were correlated with eight various models in order to selection the best model for these systems. The kinetic adsorption data were well described by fractal-like pseudo-first-order (FL-PFO) and IKL models for SMZ and MSMZ adsorbents, respectively. Eight error functions were used to estimate the best fitted isotherm and kinetic models. [ABSTRACT FROM AUTHOR]

Due to the imperative global energy transition crisis, hydrogen storage and adsorption technologies are becoming popular with the growing hydrogen economy. Recently, complex hydrides have been one of the most reliable materials for storing and transporting hydrogen gas to various fuel cells to generate clean energy with zero carbon emissions. With the ever-increasing carbon emissions, it is necessary to substitute the current energy sources with green hydrogen-based efficient energy-integrated systems. Herein, we propose an input-output model that comprehends complex hydrides such as lithium and magnesium alanates, amides and borohydrides to predict, estimate, and directly analyse hydrogen storage and adsorption. A critical and thorough comparative analysis of the respective complex hydrides for hydrogen adsorption and storage is discussed, elucidating the storage applications in water bodies. Several industrial scale-up processes, economic analysis, and plant design of hydrogen storage and adsorption approaches are suggested through volumetric and gravimetric calculations. [Display omitted] • The paper demonstrated the following highlights and key points. • There is a dire need to shift towards modern sustainable renewables. • This research gave projections of hydrogen storage in metal hydrides. • The work gave negative useable hydrogen for lithium amide. • The model compared the gravimetric & volumetric values with USDOE conjecture. [ABSTRACT FROM AUTHOR]

Adsorption is a promising way to remove persistent organic pollutants (POPs), a major environmental issue. With their high porosity and vast surface areas, MOFs are suited for POP removal due to their excellent adsorption capabilities. This review addresses the intricate principles of MOF-mediated adsorption and helps to future attempts to mitigate organic water pollution. This review examines the complicated concepts of MOF-mediated adsorption, including MOF synthesis methodologies, adsorption mechanisms, and material tunability and adaptability. MOFs' ability to adsorb POPs via electrostatic forces, acid-base interactions, hydrogen bonds, and pi-pi interactions is elaborated. This review demonstrates its versatility in eliminating many types of contaminants. Functionalizing, adding metal nanoparticles, or changing MOFs after they are created can improve their performance and remove contaminants. This paper also discusses MOF-based pollutant removal issues and future prospects, including adsorption capacity, selectivity, scale-up for practical application, stability, and recovery. These obstacles can be overcome by rationally designing MOFs, developing composite materials, and improving material production and characterization. Overall, MOF technology research and innovation hold considerable promise for environmental pollution solutions and sustainable remediation. Desorption and regeneration in MOFs are also included in the review, along with methods for improving pollutant removal efficiency and sustainability. Case studies of effective MOF regeneration and scaling up for practical deployment are discussed, along with future ideas for addressing these hurdles. [ABSTRACT FROM AUTHOR]

This research paper presents a direct approach to synthesize AgNPs deposited on polyoxometalate/ZIF-8 on-site (referred to as AgNPS@PW@ZIF-8) to develop a highly efficient photocatalyst in the water treatment. Phosphotungestic acid (PW) serves a multi-purpose in this context: it acts as a bridge layer between AgNPs and Zeolitic Imidazolate Framework-8 (ZIF-8), a local reducing agent, and a catalyst for electron transfer during the photocatalysis process. A comprehensive characterization of the resulting nanostructure was performed utilizing an array of techniques, such as XRD, FTIR, EDX, TEM, BET, Raman, and TGA. The nanostructure that was created exhibited effective removal of Congo red at different pH levels via a combination of simultaneous adsorption and photocatalysis. After 60 min at pH 7, the dye molecules were completely eliminated in the presence of 0.5 g/L AgNPS@PW@ZIF-8 at room temperature. The charge transfer can be facilitated by the PW bridge layer connecting AgNPs and ZIF-8, owing to the photoactive characteristics and strong electron transfer capabilities of PW molecules. Strong electron transferability of PW between Ag nanoparticles and ZIF-8 facilitates charge transfer and significantly improves the photocatalytic performance of ZIF-8. Moreover, the nanostructure demonstrated great structural stability and recyclability, sustaining a high efficiency of removal throughout five consecutive cycles through the implementation of a simple procedure. Widespread applications of the developed nanostructure in aquatic environments for adsorption and photocatalytic reactions are possible. • AgNPS@PW@ZIF-8 exhibited highly efficient adsorbent/photocatalyst in CR removal. • Charge transfer can be facilitated by the PW bridge layer connecting AgNPs and ZIF-8. • The nanostructure showed high structural stability and recyclability. [ABSTRACT FROM AUTHOR]

The structure and properties of basic metal-organic frameworks (MOFs) continue to exhibit low Cd(II) uptake and selectivity. Assembly of same zinc-based MOF building blocks into a dual-zinc MOF@MOF composite could offer a promising avenue for efficiently capturing Cd(II) from aqueous solutions. This paper reports a dual-zinc MOF@MOF (Zn-BTC@ZIF-8, DZM) adsorbent, which was constructed for boosting the performances of adsorption and separation. The adsorption behavior of Cd(II) onto DZM from aqueous solution is thoroughly examined at room temperature. Results indicates that the DZM demonstrates significant capability in capturing Cd(II), attributed to the synergistic effects of Zn-BTC and ZIF-8 with diverse active sites, appropriate pore sizes and shapes, stable dual zinc bonding interaction, and more. The maximum Cd(II) uptake capacity reached 150 mg/g, with rapid attainment of adsorption equilibrium within just 20 min, surpassing the performance of other reported adsorbents in the literature. The adsorption data align well with both the Freundlich and pseudo-second-order kinetic models. The process of adsorption is a process of spontaneous heat absorption and increasing degrees of freedom. Particularly noteworthy is the sustained effectiveness of DZM in capturing Cd(II) even after the fifth cycle. This research introduces a fresh approach to crafting desirable MOF@MOF configurations, thereby advancing their potential utility in Cd(II) removal from water. [Display omitted] • A new-style dual-zinc MOF@MOF (Zn-BTC@ZIF-8) adsorbent was first constructed. • The Zn-BTC@ZIF-8 composite exhibits adsorption performance toward Cd(II). • Double MOF structure is beneficial to expose more active sites and facilitate Cd(II) capture. [ABSTRACT FROM AUTHOR]

[Display omitted] The phenomenon that calcium alginate does not exhibit high adsorption capacity as a carrier material has not been reasonably explained or solved. In this paper, a new viewpoint that the orbital energy level of metal ions and the binding degree of the α-l-guluronate and β-d-mannuronate units affect the adsorption performance of the composite was innovatively proposed. Taking barium alginate (BA) as an example, the possibility of replacing calcium alginate is discussed. Barium alginate/graphene oxide (BA/GO) membranes and three-dimensional (3D) barium alginate-bentonite-graphene oxide derived (3D-BA) hydrogels were prepared by vacuum freeze-drying to remove methylene blue. The structure and morphology of the prepared adsorbents were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy. The effects of adsorbent dosage, doping ratio, temperature, contact time, pH value and initial dye concentration on the adsorption performance of BA composites were investigated. The adsorption capacities of the BA/GO and 3D-BA materials were 1011.3 and 710.3 mg/g, respectively. The BA/GO membrane exhibited stable filtration performance against high concentrations of dyes. Benefiting from the strong interaction between bentonite, sodium alginate and Ba2+, the 3D-BA hydrogel showed higher thermal stability and better adsorption efficiency than other materials. The Elovich kinetic model and Sips equation can appropriately describe the adsorption process. The results show that barium alginate is a better carrier material than calcium alginate. [ABSTRACT FROM AUTHOR]

[Display omitted] Polyacrylonitrile (PAN)-based materials have been studied for decades as uranium (U(VI)) adsorbents, because the further products of abundant nitrile groups, amidoxime (AO) groups, show great affinity for U(VI) ions. However, excessive amidoximation could cause the shrinkage of PAN fibers, resulting in decreased adsorption performance. Hence, an amino-reinforced amidoxime (ARAO) swelling layer was constructed on the PAN fiber surface (PAN-NH 2 -AO) by modification of the strongly hydrophilic amino group to prevent shrinkage. The molecular chains in the ARAO swelling layer would be swelled due to the adsorption of a large amount of water. Simultaneously, U(Ⅵ) ions can penetrate into the ARAO swelling layer with water molecules and coordinate with amino or AO groups, leading to increased adsorption performance. PAN-NH 2 -AO exhibited maximum U(VI) and water adsorption capacities of 492.61 mg g−1 and 20.32 g g−1 at 25 ℃ with a swelling ratio of 20.73%, respectively. The adsorption capacity of PAN-NH 2 -AO was 0.312 mg g−1 after a 91-day immersion in Yellow Sea, China. The study of the adsorption thermodynamics and kinetics of PAN-NH 2 -AO showed that the adsorption process was spontaneous homogeneous chemical adsorption. This paper proposes a novel method to obstruct amidoximation induced shrinkage and to maximize the potential application of PAN-based materials. [ABSTRACT FROM AUTHOR]

The paper demonstrates the capability of using cockle shells as an adsorbent for phosphorus removal from simulated petrochemical wastewater, focusing on the actual condition of the petrochemical facultative pond. In this study, the physicochemical properties of shell powder were determined, such as the functional groups, surface morphology, crystalline structure, and surface area using FTIR, SEM, EDX, XRD, and BET. It was observed that the optimum conditions for effective phosphorus removal are under the presence of rotational speed (125 rpm), higher dosage (7 g/L), and larger surface area (smaller particle size) of the shell powder. Fine powder achieved up to 52.27% of phosphorus removal after 40 min compared to coarse powder which could only give 16.67% removal. Additionally, calcined shell powder demonstrated a higher phosphorus removal rate, i.e., up to 62.37%, compared to raw shell powders. The adsorption isotherm was studied using Langmuir and Freundlich models, but the isothermal data fit better for the Freundlich model (R2 = 0.9836). Overall, this study has successfully generated a greener and low-cost adsorbent. [Display omitted] • The paper discussed the preparation of adsorbent from raw and calcined cockleshell. • The physical and morphological analysis of the adsorbent has been studied. • The removal factors for phosphorous adsorption have been studied. [ABSTRACT FROM AUTHOR]

Two flaws in concepts were identified and discussed in the paper ("Removal of Pb(II) from contaminated waters using cellulose sulfate/chitosan aerogel: Equilibrium, kinetics, and thermodynamic studies". J. Environ. Manag. 286, 112167; https://doi.org/10.1016/j.jenvman.2021.112167). In the literature, the Radke–Prausnitz model is expressed in different forms, but some of them are incorrect. The first flaw is related to the nonlinear form of the Radke–Prausnitz model. The nonlinear form of this three parameters model is expressed correctly as q e = A R P B R P C e β A R P + B R P C e β – 1 . The units of two parameters are A RP (L/kg) and B RP [(mol/kg)/(mol/L) β ] by considering q e (mol/kg) and C e (mol/L). The limitation for its exponent is 0≤ β ≤ 1. This model is developed by two authors (Radke and Prausnitz). The correct paper (DOI: 10.1021/i160044a003) cited as reference of this model is "Radke, C.J., Prausnitz, J.M., 1972. Adsorption of organic solutes from dilute aqueous solution of activated carbon. Ind. Eng. Chem. 11, 445–451". The second is the misconception about the unit of the Langmuir constant (K L ; L/mg). The correct unit of K L is litre per milligram of adsorbate (i.e., Pb ions), not litre per milligram of adsorbent (the cellulose sulfate/chitosan aerogel material as reported by Najaflou and co-workers. They proposed a new equation [ K L (L/mg) × m/V (mg/L)] to convert the Langmuir constant and then applied it to calculate the thermodynamic parameters of the adsorption process. The m / V is a solid/liquid ratio (g/L or kg/L). However, this conversion and application are mistakes that were thoroughly discussed in this paper. The correction is K E q o = 1 γ A d s o r b a t e × K L L m o l × C o m o l L , with C ° (1 mol/L by definition) being the standard state of solute and γ A d s o r b a t e (dimensionless) being the activity coefficient of adsorbate in solution. To avoid unexpected mistakes, the present authors suggest that researchers should have a correct citation (citing the original reference instead of using secondary references) and check the consistency of units (i.e., the constants of adsorption models) carefully. [ABSTRACT FROM AUTHOR]

Wastewater containing toxic substances is a major threat to the health of both aquatic and terrestrial ecosystems. In order to treat wastewater, nanomaterials are currently being studied intensively due to their unprecedented properties. The unique features of nanoparticles are prompting an increasing number of studies into their use in wastewater treatment. Although several studies have been undertaken in recent years, most of them did not focus on some of the nanomaterials that are now often utilized for wastewater treatment. It is essential to investigate the most recent advances in all the types of nanomaterials that are now frequently employed for wastewater treatment. The recent advancements in common nanomaterials used for sustainable wastewater treatment is comprehensively reviewed in this paper. This paper also thoroughly assesses unique features, proper utilization, future prospects, and current limitations of green nanotechnology in wastewater treatment. Zero-valent metal and metal oxide nanoparticles, especially iron oxides were shown to be more effective than traditional carbon nanotubes (CNTs) for recovering heavy metals in wastewater. Iron oxide achieved 75.9% COD (chemical oxygen demand) removal efficiency while titanium oxide (TiO 2) achieved 75.5% COD. Iron nanoparticles attained 72.1% methyl blue removal efficiency. However, since only a few types of nanomaterials have been commercialized, it is important to also focus on the economic feasibility of each nanomaterial. This study found that the large surface area, high reactivity, and strong mechanical properties of nanoparticles means they can be considered as a promising option for successful wastewater treatment. [Display omitted] • The current state of nanotechnology research for wastewater treatment is reviewed. • Iron oxides showed to be more effective than traditional CNTs. • Iron oxide achieved 75.9% COD removal efficiency while TiO 2 could remove 75.5%. • Long-term effects on wastewater treatment could be achieved by using nanocomposites. • Before nanotechnology to be widely used, it must become affordable and commercialized. [ABSTRACT FROM AUTHOR]

Large amounts of process water with considerable concentrations of recalcitrant organic contaminants, such as polycyclic aromatic hydrocarbon (PAHs), phenolic compounds (PCs), and benzene, toluene, ethylbenzene, and xylene (BTEX), are generated by several segments of oil and gas industries. These segments include refineries, hydraulic fracturing (HF), and produced waters from the extraction of shale gas (SGPW), coalbed methane (CBMPW) and oil sands (OSPW). In fact, the concentration of PCs and PAHs in process water from refinery can reach 855 and 742 mg L−1, respectively. SGPW can contain BTEX at concentrations as high as 778 mg L−1. Adsorption can effectively target those organic compounds for the remediation of the process water by applying carbon-based adsorbents generated from organic feedstocks. Such organic feedstocks usually come from organic waste materials that would otherwise be conventionally disposed of. The objective of this review paper is to cover the scientific progress in the studies of carbon-based adsorbents from organic feedstocks that were successfully applied for the removal of organic contaminants PAHs, PCs, and BTEX. The contributions of this review paper include the important aspects of (i) production and characterization of carbon-based adsorbents to enhance the efficiency of organic contaminant adsorption, (ii) adsorption properties and mechanisms associated with the engineered adsorbent and expected for certain pollutants, and (iii) research gaps in the field, which could be a guidance for future studies. In terms of production and characterization of materials, standalone pyrolysis or hybrid procedures (pyrolysis associated with chemical activation methods) are the most applied techniques, yielding high surface area and other surface properties that are crucial to the adsorption of organic contaminants. The adsorption of organic compounds on carbonaceous materials performed well at wide range of pH and temperatures and this is desirable considering the pH of process waters. The mechanisms are frequently pore filling, hydrogen bonding, π−π, hydrophobic and electrostatic interactions, and same precursor material can present more than one adsorption mechanism, which can be beneficial to target more than one organic contaminant. Research gaps include the evaluation of engineered adsorbents in terms of competitive adsorption, application of adsorbents in oil and gas industry process water, adsorbent regeneration and reuse studies, and pilot or full-scale applications. [Display omitted] • Organic contaminants are a concern in process water (PW) from oil and gas operations. • Scientific progress in carbon-based adsorbents for organic contaminants is covered. • Adsorption efficiency is enhanced with production conditions of carbon-based material. • Future study must focus on real PW to assess adsorption efficiency and competitivity • Research gaps include regeneration/reuse and environmental impacts of spent adsorbent. [ABSTRACT FROM AUTHOR]

The release of uranium from uranium tailings into the aqueous environment is a complex process controlled by a series of interacting geochemical reactions. In this paper, uranium tailings from a uranium tailings pond in southern China were collected at different depths by means of borehole sampling and mixed to analyze the fugacity state of U. Static leaching experiments of U at different pH, oxidant concentration and solid-to-liquid ratios and dynamic leaching experiments of U at different pH were carried out, and the adsorption and desorption behaviour of U in five representative stratigraphic media were investigated. The results show that U is mainly present in the residue state in uranium tailings, that U release is strong in the lower pH range, that the leached U is mainly in the form of U(VI), mainly from the water-soluble, Fe/Mn oxides and exchangeable fraction of uranium tailings, and that the reduction in U leaching at higher pH is mainly due to the combined effect of precipitation formation and larger particle size of platelets in uranium tailings. Experiments with different oxidant concentrations and solid-liquid ratios showed that the oxygen-enriched state and low solid-liquid ratios were favorable for the leaching of U from uranium tailings. Adsorption and desorption experiments show that U is weakly adsorbed in representative strata, reversibly adsorbed, and that U is highly migratory in groundwater. The present research results have important guiding significance for the management of existing uranium tailings ponds and the control of U migration in groundwater, which is conducive to ensuring the long-term safety, stability and sustainability of uranium mining sites. [Display omitted] • The leaching of U from uranium tailings was tested under different geochemical conditions. • Adsorption behaviour of U in representative geotechnical media in uranium tailings pond areas. • The release of U from uranium tailings is mainly from the water-soluble state. • Low pH, oxygen enrichment and low solid to liquid ratio conditions favour the release of U from uranium tailings. [ABSTRACT FROM AUTHOR]

Industries today place a high premium on environmentally friendly supplies that may effectively inhibit metal dissolution at a reasonable cost. Hence, in this paper, we assessed the corrosion inhibition effectiveness of the Thiazole derivative namely, 2, 2-Dithio Bisbenzothiazole (DBBT) against mild steel (MS) corrosion in 1 M HCl. Several experimental approaches, including gravimetric analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and surface exploration using scanning electron/atomic force microscopy (SEM/AFM) and contact angle (CA), were utilized to conduct the measurements. In 1 M HCl corrosive medium at 298 K in the subsistence of 800 ppm of DBBT, this experiment indicated DBBT as an environment-friendly and sustainable corrosion inhibitor (CI) for MS, demonstrating an inhibition efficiency (IE %) of 97.71%. To deliver a deeper knowledge of the mechanism behind inhibitive behavior, the calculated thermodynamic and activation characteristics were applied. The calculated Gibbs free energy values indicated that the CI interacted physically and chemically with the MS surface, validating physio-chemical adsorption. The findings of the EIS research revealed that an upsurge in the doses of the CI is escorted by an upsurge in polarization resistance (R p) from (88.05 → 504.04) Ωcm2, and a diminution in double layer capacitance (C d l ) from (97.46 → 46.33) μFcm−2 at (50 → 800) ppm respectively, affirming the inhibitive potential of DBBT. Additionally, the greatest displacement in E c o r r value being 76.13 mV < 85 mV, indicating that DBBT act as a mixed-form CI. To study the further impacts of DBBT on the inhibition capabilities of the compound under investigation, density functional theory (DFT) and molecular dynamics (MD) simulation were employed. Chemical and electrochemical approaches are in agreement with the computational analysis indicating DBBT is the most efficient CI. [Display omitted] • The inhibition efficiency of DBBT on mild steel corrosion in 1.0 M HCl was studied. • High inhibition efficiency was attributed to the adsorption of the inhibitor molecules on the metal surface. • Langmuir adsorption isotherm exhibited the best fit to the experimental data. • The greatest displacement in E c o r r value demonstrates that DBBT acts as a mixed-type inhibitor. • Theoretical analysis displayed a correlation between inhibitive properties and molecular parameters. [ABSTRACT FROM AUTHOR]

Micro-nano plastics (MNPs) are emerging contaminants that can easily enter the food chain, posing risks to both the aquatic ecosystem and human health. Various physical, biological, and chemical methods have been explored to remove MNPs from water, and recently, adsorption technology has gained attention as an effective approach. Among the potential candidates, carbon-based adsorbent has emerged as a promising choice due to their low cost, eco-friendly nature, and sustainability. This paper summarizes recent advancements in MNP removal using carbon-based adsorbents, with a focus on the modification methods and adsorption mechanisms. Additionally, the factors influencing the adsorption performance and the methods for characterizing the adsorption mechanism are analyzed. Finally, the advantages and disadvantages of carbon-based adsorbents over other adsorbents are discussed, along with the current state of sustainable recycling and future research prospects. [Display omitted] • Typical carbon-based adsorbents for MNPs adsorption were carefully overviewed. • Different modification technologies were introduced for enhancing MNPs adsorption. • Adsorption mechanism and corresponding characterization methods were discussed. • Important factors affecting the adsorption performance of MNPs were analyzed. [ABSTRACT FROM AUTHOR]

The utilization of phthalates and bisphenol A (BPA) as the major component in plastic and its derivative industry has raised concerns among the public due to the harmful effects caused by these organic pollutants. These pollutants are found to exhibit unique physicochemical properties that allow the pollutants to have prolonged existence in the environment, thus causing damage to the environment. Since phthalates and bisphenol A are used in a variety of industrial applications, the industry must recover these compounds from its water before releasing the pollutants into the environment. As a result, these materials have a promising future in industrial applications. Therefore, the discovery of new quick and reliable abatement technologies is important to ensure that these organic pollutants can be detected and removed from the water sources. This review highlights the use of the adsorption method to remove phthalates and BPA from water sources by employing novel modified adsorbent magnetite functionalized covalent organic frameworks (MCOFs). MCOFs is a new class of porous materials that have demonstrated promising features in a variety of applications due to their adaptable structures, significant surface areas, configurable porosity, and customizable chemistry. The structural attributes, functional design strategies, and specialized for environmental applications before offering some closing thoughts and suggestions for further research were discussed in this paper in addition to developing an innovative solution for the industry to the accessibility for clean water. [Display omitted] • Magnetite nanoparticles covalent organic frameworks (MCOFs) used to adsorb phthalates and bisphenol A (BPA) from water. • Phthalates and bisphenol A are widely used in industrial applications and must be recovered from water sources before releasing to the environment. • MCOFs showcases promising features due to their structural attributes, functional design strategies and customisable chemistry. • Covalent organic frameworks (COFs) are potential surface coating agents for magnetite nanoparticles (MNPs) for versatile applications usage. • MCOFs are cogent strategy in fulfiling the second and sixth goals of United Nations Sustainable Development Goals (SDGs). [ABSTRACT FROM AUTHOR]

This comment discussed the calculation of equilibrium constant and thermodynamic parameters in the paper of Kayalvizhi et al. (2022). This paper is of high academic value, however, there are some calculation and quotation errrors. The equilibrium constant K evolved from the distribution coefficient has a dimension of L/g, which is not the standard equilibrium constant, therefore, it cannot be used to calculate the thermodynamic parameters. This comment firstly analyzed the calculation errors made by Kayalvizhi et al. (2022), then established the relationship between distribution coefficient and standard equilibirum constant, and recalculated the thermodynamic parameters by using the correct distribution coefficient equation. As a research paper, authors not only provide the originality and novelty, but also give its correct results. This comment can bring to the attention of readers, authors, editors and reviewers about the thermodynamic calculation. At the same time, it is helpful to avoid the misuse and propagation of the incorrect equation in the area of adsorption thermodynamics. • The thermodynamic calculation by using distribution coefficient has a dimensional problem. • The relationship between distribution coefficient and standard equilibirum constant was derived. • The correct methods for computing thermodynamic parameters provided here. [ABSTRACT FROM AUTHOR]

This paper evaluates the potential use of date palm leaf biochar as a climate change solution through CO 2 capture and sequestration. The pyrolysis of date palm leaf was performed at different temperatures 300°, 400°, 500°, and 600 °C. The physicochemical characteristics of the synthesized biochar were examined using Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX), Fourier transforms infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). Direct gas-solid interaction was carried out in an integrated Fluidized Bed Reactor (FBR), connected with a gas analyzer for maximum and effective mixing between the biochar and CO 2. LabView program was used as data acquisition for an instantaneous calculation of CO 2 adsorption. This study showed that the date palm biochar as porous carbon-based materials has high CO 2 adsorption capacity through physisorption and chemisorption progressions. The adsorption results showed a maximum CO 2 capture percentage of 0.09 kg CO 2 /kg, 0.15 kg CO 2 /kg, 0.20 kg CO 2 /kg, and 0.25 kg CO 2 /kg palm biochar synthesized at 300 °C, 400 °C, 500 °C, and 600 °C, respectively. This paper paid attention to the inexpensive technology applied in CO 2 sequestration, where fluidization provides well mixing of biochar particles with low operation cost. • This study aims to prepare different biochar from date palm leaf (DPL) waste and evaluate its CO 2 capture and sequestration capacity. • Biochar samples were pyrolyzed at different temperatures and were characterized using SEM-EDS, FTIR, TGA, and XRD. • The gas-solid reaction was achieved in the integrated fluidized bed reactor on the different DPL biochar particles. Results indicated that the DPL biochar has a high CO 2 adsorption capacity. • The CO 2 sequestration of the DPL ranged from 07 to 25%, based on different temperatures of biochar pyrolysis. [ABSTRACT FROM AUTHOR]

The overuse of thiamethoxam (THM) has threatened the survival of living organisms and it is necessary to find an environmentally friendly material to remove THM frequently detected in water. Biochar prepared from cow manure modified with ZnCl 2 (Zn-CBC) was used to remove THM. Compared to the unmodified cow manure biochar (CBC), the removal ratio of THM by Zn-CBC was enhanced 35 times. In the mechanistic analysis, SEM and BET showed that Zn-CBC had a good pore structure and its specific surface area (166.502 m2 g−1) increased to 17 times that of CBC, indicating that Zn-CBC had good pore adsorption properties. The adsorption kinetic and isotherm implied that the main mechanism was chemisorption including π-π interaction and H-bonding. Furthermore, the stable graphitized structure of Zn-CBC allowed for efficient adsorption and reusability. In addition, this study constructed an intelligent prediction model using batch experiment data, and the high R2 (0.978) and low RMSE (0.057) implied that the model could accurately and quantitatively predict the adsorption efficiency. This paper provides a novel perspective to simultaneously remove the neonicotinoid insecticides and realize the resource utilization of cow manure. [Display omitted] • ZnCl 2 -modified biochar derived from cow manure was used to adsorb THM. • The specific surface area of Zn-CBC was 17 times that of CBC. • Zn-CBC had a stable adsorption capacity in a wide pH range. • The main adsorption mechanisms are pore filling, π-π conjugation and H bonding. • Quantitative prediction of THM removal ratio by artificial intelligence. [ABSTRACT FROM AUTHOR]

Antibiotics, a kind of containments with the properties of widely distributed and difficult to degrade, has aroused extensive attention in the world. As a prevalent agricultural waste, straws can be utilized to prepare biochar (straw-derived biochar, SBC) to remove antibiotics from aquatic environment. To date, although a number of review papers have summarized and discussed research on biochar application in wastewater treatment and soil remediation, there are few reviews on SBC for antibiotic removal. Due to the limitations of poor adsorption and degradation performance of the pristine SBC, it is necessary to modify SBC to improve its applications for antibiotics removal. The maximum antibiotic removal capacity of modified SBC could reach 1346.55 mg/g. Moreover, the adsorption mechanisms between modified SBC and antibiotics mainly involve π-π interactions, electrostatic interactions, hydrophobic interactions, and charge dipole interactions. In addition, the modified SBC could completely degrade antibiotics within 6 min by activating oxidants, such as PS, PDS, H 2 O 2 , and O 3. The mechanisms of antibiotic degradation by SBC activated oxidants mainly include free radicals (including SO 4 •−, •OH, and O 2 •−) and non-free radical pathway (such as, 1O 2 , electrons transfer, and surface-confined reaction). Although SBC and modified SBC have demonstrated excellent performance in removing antibiotics, they still face some challenges in practical applications, such as poor stability, high cost, and difficulties in recycling. Therefore, the further research directions and trends for the development of SBC and biochar-based materials should be taken into consideration. [ABSTRACT FROM AUTHOR]

Using biochar as a partial replacement of Portland cement in cementitious materials is a promising solution to mitigate negative environmental impacts. However, current studies in available literature primarily focus on the mechanical properties of composites made with cementitious materials and biochar. Therefore, this paper reports the effects of the type of biochar, the percentage of biochar addition, and the particle size of the biochar on the removal efficiency of Cu, Pb, and Zn, as well as the effect of contact time on the removal efficiency of Cu, Pb, and Zn, along with the compressive strength. The peak intensities of OH−, CO 3 2− and Calcium Silicate Hydrate (Ca–Si–H) peaks increase with increasing biochar addition levels, reflecting increased hydration product formation. The reduction of particle size of biochar causes the polymerization of the Ca–Si–H gel. However, no significant changes were observed in heavy metal removal, irrespective of the percentage of biochar addition, the particle size of biochar, or the type of biochar added to the cement paste. Adsorption capacities above 19 mg/g, 11 mg/g and 19 mg/g for Cu, Pb and Zn were recorded in all composites at an initial pH of 6.0. The Pseudo second order model best described the kinetics of the Cu, Pb, and Zn removal. The rate of adsorptive removal increases with the decrease in the density of the adsorbents. Over 40% of Cu and Zn were removed as carbonates and hydroxides through precipitation, whereas over 80% of Pb removal was via adsorption. Heavy metals bonded with OH−, CO 3 2− and Ca–Si–H functional groups. The results demonstrate that biochar can be used as a cement replacement without negatively impacting heavy metal removal. However, neutralization of the high pH is needed before safe discharge. [Display omitted] • Reducing biochar particle size did not increase removal site availability. • Pb removal is low at pH > 11.0 due to dissolution as Pb(OH)- ions. • Chemical bonding and precipitation are the main heavy metals removal mechanisms. • Adsorbed heavy metals are desorbed when back washed with pH < 2.0 water. • Cement-biochar adsorption capacity is similar to zeolites, biochar, activated carbon. [ABSTRACT FROM AUTHOR]

The presence of heavy metal ions and emerging pollutants in water poses a great risk to various biological ecosystems as a result of their high toxicity. Consequently, devising efficient and environmentally friendly methods to decontaminate these waters is of high interest to many researchers around the world. Among the varied water treatment and desalination means, adsorption and photocatalysis have been widely employed. However, the discussion and analysis of the use of zeolite-based composites as adsorbents are somehow minimal. The porous aluminosilicates (zeolites) are excellent candidates in wastewater treatment owing to various mechanisms of pollutants removal that they possess. The purpose of this review is thus to provide a synopsis of the current developments in the fabrication and application of nanocomposites based on zeolite as adsorbents and photocatalysts for the extraction of heavy metals, dyes and emerging pollutants from wastewaters. The review goes on to look into the effect of weight ratio on photocatalyst, photodegradation pathways, and various factors that influence photocatalysis and adsorption. • The degree of presence of heavy metals and emerging pollutants is analysed in depth. • A comparative analysis of zeolite based composites as adsorbents is undertaken. • The paper also provides current developments in the fabrication of zeolites based adsorbents and photocatalysts. • A critical review on the impact of weight ratio in the performance of these zeolite based adsorbents is also undertaken. [ABSTRACT FROM AUTHOR]

The serious damage caused by volatile organic compounds (VOCs) to the environment and human health has attracted worldwide attention. Adsorption methods are among of the most promising VOC emission reduction technologies, with high cost-effectiveness, simple operation, and low energy consumption. The use of an appropriate adsorbent is very important for the removal of VOCs. Based on the preparation of high-performance materials with ideal pore structure and effective adsorption of acetone, in this paper we prepared the zeolite framework adsorbents SiO 2 @ZIF-67 and SiO 2 @ZIF-67/Cs as well as the high-temperature calcined C–SiO 2 @ZIF-67/Cs composites. The results of acetone adsorption tests showed that C–SiO 2 @ZIF-67/Cs had 55.7% and 32.4% higher adsorption capacity for acetone than SiO 2 @ZIF-67 and SiO 2 @ZIF-67/Cs, respectively. The high-temperature calcination can increase the specific surface area, greatly improving the adsorption capacity of the composite for acetone. The composite maintained good adsorption efficiency after five adsorption–desorption tests. Zeolite imidazolate framework adsorbent C–SiO 2 @ZIF-67/Cs was firstly obtained by the pyrolysis of as-prepared SiO 2 @ZIF-67/Cs compound. High-temperature calcination increases the specific surface area and greatly improves the adsorption capacity for acetone. [Display omitted] • Zeolite imidazolate framework adsorbents SiO 2 @ZIF-67 and SiO 2 @ZIF-67/Cs were firstly prepared. • C–SiO 2 @ZIF-67/Cs composite adsorbent was obtained by subsequent pyrolysis of SiO 2 @ZIF-67/Cs. • C–SiO 2 @ZIF-67/Cs showed the best adsorption capacity for acetone. • All three adsorbents retained more than 80% of the initial adsorption capacity after five cycles. • It demonstrates the broad application prospects of Zeolite imidazolate framework adsorbents in VOC pollutant treatment. [ABSTRACT FROM AUTHOR]

Radioactive Cs+ is one of the most dangerous environmental pollutants. It is necessary for radioactive Cs+ management and removal. Titanium-type cesium ion sieve with a strong Ti–O bond has the advantages of structural stability, radiation resistance and no secondary contamination, which is a promising adsorbent material. In this paper, The CTO (Cs 2 Ti 6 O 13) is prepared for the first time by sol-gel and de-templating methods, and cesium ion sieves (HTO/PMMA) are further obtained with diluted HCl elution. Compared with the ionic sieves (HTO) prepared by direct sol-gel method, the adsorption capacity is improved from 224.32 mg/g to 299.15 mg/g. The prepared HTO/PMMA has a larger specific surface area (67.282 m2/g). More exchange sites are provided for the adsorption of Cs ions. Moreover, Adsorption involves the cleavage of O–H bonds and the formation of O–Cs bonds, which is a typical ion exchange reaction. A series of batch experiments are carried out. The results showed that the equilibrium adsorption capacity of HTO/PMMA is 307.69 mg/g and remained high in the interfering ion solution as well (280.38 mg/g). The pseudo second order model and Freundlich model can well describe the ion exchange process. Thermodynamic study shows that adsorption is spontaneous and exothermic, and low temperature is conducive to adsorption in H+- Cs+ exchange system. Finally, the reusability of HTO/PMMA is evaluated. The adsorption capacity did not decrease significantly after 5 cycles of use. Therefore, HTO/PMMA is expected to be an excellent material for recovering radioactive Cs+. [Display omitted] • A novel material (HTO/PMMA) for the Adsorption of Cs+. • The HTO/PMMA has a large specific surface area (67.282 m2/g). • The adsorption mechanism involves the cleavage of O–H bonds and the generation of O–Cs bonds. • The adsorption uptake remains 281.94 mg/g after 5 cycles. [ABSTRACT FROM AUTHOR]

The current paper refers to the study of a new approach to optimizing the adsorptive properties of geopolymers by varying the aluminosilicate precursors from kaolin (K), metakaolin (MK), and coal fly ash (CFA) as internal synthesis factors. The simplex-augmented-centroid mixture design was applied to identify the optimal formulation from the three aluminosilicate precursors to develop a geopolymer (GP) with a distinctive structure that positively affects its dye adsorption efficiency. The variously formulated GP samples were tested for the removal of both methylene blue (MB-dye) and crystal violet dye (CV-dye) from an aqueous solution. The mathematical-statistical analysis of the experimental readings suggested that the generated special cubic models were significant, and thus the chosen approach was adequate for determining the optimum blending proportion. The optimization tools indicated that the optimal mixture from the three aluminosilicate precursors for developing a GP with high adsorption efficiency was 58% MK, 42% K, and 0% CFA. The optimized geopolymer (GP O) was synthesized and then analyzed using a variety of physicochemical techniques, which revealed the presence of an amorphous N-A-S-H gel-rich porous structure as an influencing property on the geopolymer's organic dye adsorption efficiency. The dependence of the adsorption mechanism of both MB-dye and CV-dye by GP O on the adsorbent dosage, contact time, initial dye concentration, temperature, and solution pH was evaluated. The isothermic and kinetic experimental readings for MB and CV-dyes adsorption by GP O were well fitted to the pseudo-second-order and Freundlich models, with an exothermic, favorable, and spontaneous adsorption reaction thermodynamically. The experimental studies in the lab scale on GP O produce comparable results. From these results, it has been concluded that the accuracy and feasibility of the mixture design simulation succeeded in optimizing and developing a geopolymeric sorbent material with great potential as an excellent economical agent for removing cationic dyes from aqueous media. This point represents an added value compared to traditional non-optimized geopolymer absorbents. Besides, this geopolymer material represents a significant application possibility for water treatment and remediation of hazardous dye pollutants. • The geopolymer adsorbent was optimized using a mixture design methodology. • The optimized geopolymer has been developed using a mixture of kaolin (58%) and metakaolin (42%). • The optimized geopolymer showed maximum adsorption capacities of 63.79 and 73.00 mg/g for the MB and CV dyes, respectively. • The adsorption mechanism fits well with the Langmuir isothermal and pseudo-second-order kinetic models. • The optimized geopolymer adsorbent represents a relatively low synthesis cost. [ABSTRACT FROM AUTHOR]

Lead is a toxic heavy metal that is highly harmful to humans. Developing fast, efficient, and separable materials to treat lead-contaminated wastewater is challenging. In this paper, Cu-based MOF composite (SCC-CuMOF) was prepared by in-situ growth method and used for the removal of Pb2+ from aqueous solutions. The obtained materials were characterized by field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS) mapping, Brunauer-Emmett-Teller (BET) specific surface area, X-ray diffraction (XRD) and infrared spectroscopy (IR). The effects of pH, coexisting ions, contact time, initial ion concentration, and temperature on the removal of Pb2+ were investigated. SCC-CuMOF exhibited excellent adsorption performance on Pb2+. Adsorption of Pb2+ on SCC-CuMOF were in accordance with the pseudo-second-order model and Langmuir model. The adsorption thermodynamic study suggested that the adsorption process was spontaneous and endothermic. The results revealed that Pb2+ might be adsorbed onto SCC-CuMOF via ion exchange and coordination interaction. In general, SCC-CuMOF has the potential to remove Pb2+ from wastewater rapidly and efficiently. The study prepared SCC-CuMOF composites by in situ growth of Cu-based MOF on the hydrogel SCC-Cu surface for the removal of Pb2+ from aqueous solutions. [Display omitted] • Cu-based MOF composite (SCC-CuMOF) was prepared by in-situ growth method. • SCC-CuMOF exhibited excellent adsorption performance on Pb2+. • The maximum adsorption capacity for Pb2+ was 531.38 ​mg/g at 308 ​K. • The mechanism of Pb2+ adsorption on composites is thoroughly discussed. [ABSTRACT FROM AUTHOR]

Increased environmental pollution is a critical issue that must be addressed. Photocatalytic, adsorption, and membrane filtration methods are suitable in environmental governance because of their high selectivity, low cost, environment-friendly nature, and excellent treatment efficiency. Graphitic carbon nitride (g-C 3 N 4) quantum dots (QDs) have been considered as photocatalysts, adsorbents, and membrane materials for wastewater treatments, owing to their stability, adsorption capacity, photochemical properties, and low toxicity and cost. This review summarizes g-C 3 N 4 QD synthesis techniques, operating parameters affecting the removal performance in the treatment process, modification effects with other semiconductors, and benefits and drawbacks of g-C 3 N 4 QD-based materials. Furthermore, this review discusses the practical applications of g-C 3 N 4 QDs as adsorbents, photocatalysts, and membrane materials for organic and inorganic contaminant treatments and their value-added product formation potential. Modified g-C 3 N 4 QD-based material adsorbents, photocatalysts, and membranes present potentially applicable effects, such as removal of most waterborne contaminants. Excellent results were obtained for the reduction of methyl orange, bisphenol A, tetracycline, ciprofloxacin, phenol, rhodamine B, E. coli , and Hg. Overall, this paper provides comprehensive background on g-C 3 N 4 QD-based materials and their diverse applications in wastewater treatment, and it presents a foundation for the enhancement of similar unique materials in the future. [ABSTRACT FROM AUTHOR]

The highly promising formaldehyde (HCHO)-removing materials are essential for eliminating interior pollution to safeguard the public's health with increasing indoor HCHO contamination situations being recorded on a global scale. In the paper, bamboo charcoal (BC) was activated with boric acid to prepare bamboo-based activated carbon (BAC), and then impregnated with ammonium acetate solution to successfully develop porous adsorbent with ammonium acetate particles (N/BAC), which was applied to remove low concentration of HCHO at room temperature. The adsorption performance for HCHO was systematically investigated while the surface chemical properties and microstructure of the as-prepared adsorbents were described and analyzed. The specific surface area, total pore volume and microporous volume of N/BAC sample were 240.09 m2/g, 0.27 cm3/g and 0.12 cm3/g, which increased by 42.40 m2/g, 0.15 cm3/g and 0.03 cm3/g compared with BAC sample, respectively. The specific surface area and the microporous volume, as well as the content of oxygen- and nitrogen-containing functional groups of N/BAC sample were augmented by contrast with other samples, and numerous ammonium acetate particles were present on the surface. Precisely because of this, the N/BAC sample exhibited a high removal rate of 98.89%, which was 18.38% greater than that of BAC sample. A superior correlation coefficient (0.9999) from the experimental values of the kinetics and the fitted values of the pseudo-second-order kinetic model demonstrated that the adsorption process of HCHO on N/BAC sample was physical-chemical combined adsorption. The adsorption of HCHO on N/BAC sample was investigated under different humidity, and the results showed that the adsorbent yet had excellent adsorption capacity (87.93%) under RH 75%. Moreover, the N/BAC sample was renewable, and the removal rate still reached 82.81% after five cycles of regeneration. Therefore, the as-prepared adsorbent is an effective, economical and sustainable material, and could be used to remove HCHO from real contaminated indoor air. [Display omitted] • BAC with ammonium acetate particles (N/BAC) were tested maidenly for removing HCHO. • N/BAC exhibited excellent adsorptivity and regenerability. • Compared with BAC, N/BAC has larger specific surface area and more functional groups. [ABSTRACT FROM AUTHOR]

The quantitative description of the equilibrium data by the isotherm models is an indispensable link in adsorption studies. The previous review papers focus on the underlying assumptions, fitting methods, error functions and practical applications of the isotherm models, usually ignoring their curve characteristics, selection criteria and common controversies. The main contents of this review include: (i) effect of the model parameters on the isotherm curves; (ii) determination of the site energy distribution; (iii) selection criteria of the isotherm models; and (iv) elimination of some common controversies. It is of great significance to reveal the curve characteristics for selecting a proper isotherm model. The site energy distribution is conducive to understanding the physicochemical properties of the adsorbent surface. The complete isotherm is recommended to be correlated with the experimental data. The model parameter q max should be cautiously adopted for comparison of the adsorbent performance. The residual plot can be used to diagnose the fitting quality of the isotherm models further. This review also addresses some common mistakes and controversies and thereby avoids their propagation in future publications. [Display omitted] • This work reveals the curve types represented by the isotherm models. • This work expounds how the model parameters affect the isotherm curves profoundly. • This work addresses some controversies and mistakes concerning the isotherm models. • Goodness of fit should be evaluated by error functions and residual plot. [ABSTRACT FROM AUTHOR]

In the post-COVID scenario, the annual increase in plastic waste has taken an upsurge due to the disposal of plastic masks, gloves and other protective equipment. To reduce the plastic load ending up in landfills and oceans or dumped at roadsides, the potential of using plastic polymers in different sectors has been investigated over the years leading to their potential application in pavement laying, concrete industry, fuel generation and production of carbon-based compounds among which activated carbons (AC) is a prime example. As one of the most recommended adsorbents for removing contaminants from water and adsorbing greenhouse gases, AC creates a potential sector for using discarded plastic to further treat pollutants and approach closer to a circular economy for plastics. This paper analyses the production process, the effect of production parameters on AC characteristics and properties that aid in adsorption. The interdependence of these factors determines the surface area, porosity, relative micropore and mesopore volume, thereby defining the utility for removing contaminant molecules of a particular size. Furthermore, this work discusses the application of AC along with a summary of the earlier works leading to the existing gaps in the research area. Production costs, formation of by-products including toxic substances and adsorbate selectivity are the major issues that have restricted the commercial application of this process towards its practical use. Research aimed at valorization of plastic waste into ACs would minimize the solid waste burden, along with treating other pollutants. [Display omitted] • Activated carbon has been effectively prepared using plastic waste, particularly from PET. • Activation agent, temperature and time, posttreatment, doping affects AC properties. • AC from plastic is used to remove emerging contaminants, dyes from aqueous medium. • Has been efficiently used as adsorbant for gases like CO 2 , CF 4 , H 2 , benzene. [ABSTRACT FROM AUTHOR]

Hydroxyapatite samples doped with different metal ions (HAP-M, M ​= ​Cu, Sr, Al, Ce, and Ti) were successfully prepared by a simple co-precipitation method for effective U(VI) uptake. The applications of HAP-M in capturing U(VI) were investigated. Besides, numerous characterizations were taken to study the chemical and physical properties of HAP-M. The critical factors affecting U(VI) adsorption were examined, such as pH, contact time, initial concentration of U(VI) and solution temperature. The present study revealed that the adsorption effect of HAP for U(VI) can be affected by doping metal cations with different ionic radii, and HAP doping with Ti4+ ions increased its adsorption selectivity to U(VI). With the increase of the molar ratio of doped Ti4+ ions (5%–20%), the adsorption selection of U(VI) on HAP-Ti is also gradually increasing. HAP-Ti is a potentially efficient adsorbent in removing U(VI) from radioactive solutions. Hydroxyapatite samples doped with different metal ions (HAP-M, M ​= ​Cu, Sr, Al, Ce, and Ti) were successfully prepared by a simple co-precipitation method for effective U(VI) uptake. The applications of HAP-M in capturing U(VI) were investigated. Besides, numerous characterizations were taken to study the chemical and physical properties of HAP-M. [Display omitted] • In this paper, we systematically investigated the effect of direct doping of cations with different ionic radii into HAP on its structure and physicochemical properties, and explored their effects on U(VI) adsorption. • The as-synthesized novel metal cation-doped hydroxyapatite (HAP-Ti) exhibited better adsorption selectivity for U(VI) than other prepared hydroxyapatites. [ABSTRACT FROM AUTHOR]

Inverse vulcanized polysulfides have been used as low-cost and effective adsorbents to remediate heavy metals in wastewater. Inverse vulcanization introduces sustainable polysulfide synthesis by solving the rapid desulfurization problem of unstable polysulfides, and provides superior performance compared to conventional commercial adsorbents. The review discussed the brief applications of the inverse vulcanized polysulfides to remove heavy metal wastewater and emphasized the modified synthesis processes for enhanced uptake ratios. The characteristics of polysulfide adsorbents, which play a vital role during the removal process are highlighted with a proper discussion of the interaction between metal ions and polysulfides. The review paper concludes with remarks on the future outlook of these low-cost adsorbents with high selectivity to heavy metals. These polysulfide adsorbents can be prepared using a wide variety of crosslinker monomers including organic hydrocarbons, cooking oils, and agro-based waste materials. They have shown good surface area and excellent metal-binding capabilities compared to the commercially available adsorbents. Proper postmodification processes have enabled the benefits of repetitive uses of the polysulfide adsorbents. The improved surface area obtained by appropriate choice of crosslinkers, modified synthesis techniques, and regeneration through post-modification has made inverse vulcanized polysulfides capable of removing. [Display omitted] • Inverse vulcanized polysulfides (IVPs) can tackle heavy metal wastewater pollution. • IVPs are prepared in a simple technique and can be scaled up to kilograms or tones. • Surface area can be increased by carbonization, electrospinning, salt porogen, etc. • Choice of crosslinking monomers is important for a higher adsorption rate. • Postmodification can prevent leaching and introduce multiple uses of adsorbents. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) derived metal oxides/porous carbon nanocomposites were used as adsorbents to remove pollutants from wastewater. The adsorption performance of the metal oxides/porous carbon nanocomposites could be improved by introducing functional groups. In this study, hydroxyl-modified zirconia/porous carbon nanocomposite (C-UiO-66-OH) was prepared and tested, choosing carbamazepine as a typical pollutant. The results showed that the adsorption capacity (186.21 mg g−1) of C-UiO-66-OH was 6.96 times to that of normal UiO-66. The Langmuir isotherm model and pseudo-first-order kinetic model was well fit the adsorption process. The thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic. The adsorbent regeneration could be accomplished by washing C-UiO-66-OH with ethanol and DI water. The good adsorption/desorption performance comes from the synergistic effect of (EDA) interaction and hydrogen bond between C-UiO-66-OH and CBZ molecule. A membrane prepared by immobilizing C-UiO-66-OH into melamine foam (MF) with sodium alginate (SA) was also investigated for CBZ adsorption. The results indicated the excellent removal efficiency (86.0%) and good regeneration of the prepared membrane. Therefore, this paper provides an efficient and applicable way to remove CBZ from water. [Display omitted] • A hydroxyl-modified zirconia/porous carbon nanocomposite was synthesized. • The modified adsorbent performed high adsorption of 186.21 mg g−1 to carbamazepine. • Adsorption mechanisms are mainly π - π (EDA) interaction and hydrogen bonding. • Immobilizing powder into melamine foam with sodium alginate to prepare a membrane. • Prepared membrane has a good carbamazepine adsorption capacity and reusability. [ABSTRACT FROM AUTHOR]

While nanoscale zero-valent iron modified biochar (nZVI-BC) have been widely investigated for the removal of heavy metals, the corrosion products of nZVI and their interaction with heavy metals have not been revealed yet. In this paper, nZVI-BC was synthesized and applied for the removal of Cr(VI). Batch experiments indicated that the adsorption of Cr(VI) fit Langmuir isotherm, with the maximum removal capacity at 172.4 mg/g at pH 2.0. SEM-EDS, BET, XRD, FT-IR, Raman and XPS investigation suggested that reduction of Cr(VI) to Cr(III) was the major removal mechanism. pH played an important role on the corrosion of nZVI-BC, at pH 4.5 and 2.0, FeOOH and Fe 3 O 4 were detected as the major iron oxide, respectively. Therefore, FeOOH-BC and Fe 3 O 4 -BC were further prepared and their interaction with Cr were studied. Combining with DFT calculations, it revealed that Fe 3 O 4 has higher adsorption capacity and was responsible for the effective removal of Cr(VI) through electrostatic attraction and reduction under acidic conditions. However, Fe 3 O 4 will continue to convert to the more stable FeOOH, which is the key to for the subsequent stabilization of the reduced Cr(III). The results showed that the oxide corrosion products of nZVI-BC were subjected to the environment, which will eventually affect the fate and transport of the adsorbed heavy metal. [Display omitted] • The first sight into interaction of Cr(VI) with nZVI-BC and its oxides was provided. • pH played an important role on the corrosion of nZVI-BC. • The formation of Fe 3 O 4 was responsible for the efficient removal of Cr(VI) at pH = 2.0. • FeOOH was the key to the stable immobilization of Cr(III). [ABSTRACT FROM AUTHOR]

Recent trends in adsorption of Chromium (Cr), Copper (Cu), Lead (Pb) and Mercury (Hg) in wastewater using (i) carbonaceous materials including activated carbon (AC) and biochar (BC), and (ii) nanomaterials including nano zero-valent iron (nZVI) and MXenes have been discussed in this paper. It has been found that adsorption capacity depends largely on the adsorbent modification technique, initial pH of wastewater, dosage of adsorbent, contact time and initial concentration of the pollutants. The pH value ranges for maximum removal of Cr, Cu, Pb and Hg have been reported as 2–4, 5–6, 5–8 and 3–8, respectively. Up to 99% removal of metals has been reported using AC, BC, nZVI and MXene. The mechanism involves the reduction and chemical adsorption of metals. AC and BC have a higher surface area (up to 5000 m2/g) compared to nZVI (up to 500 m2/g) and MXene (up to 67.66 m2/g). However, the higher reactivity and regeneration capacity of nZVI and MXene make them suitable adsorbents. From a practical point of view the application of adsorbents for real effluents, cost analysis, regeneration capability and reuse of heavy metals are some aspects that need attention in future studies. The removal efficiencies of AC and BC are comparable to the nZVI and MXene. The cost analysis may be an attractive aspect to decide the future application of these adsorbents at large scale. • Recent trends in the removal of hazardous Cr, Cu, Pb and Hg metal pollutants in wastewater were reviewed using AC, BC, nZVI and MXene. • The pH value ranges for maximum removal of Cr, Cu, Pb and Hg were found as 2-4, 5-6, 5-8 and 3-8, respectively. • Possible adsorption mechanisms were discussed for the metal pollutants. • The application of AC, BC, nZVI and MXene for real effluents, their cost analysis, regeneration capability and reuse of adsorbed heavy metals are some of the aspects that need attention in future studies. [ABSTRACT FROM AUTHOR]

Increased antibiotic use worldwide has become a major concern because of their health and environmental impacts. Since most antibiotic residues can hardly be removed from wastewater using conventional treatments, alternative methods receive great attention. Adsorption is one of the most efficient and cost-effective treatment methods for antibiotics. Among the adsorbents, clay minerals have garnered increasing attention due to their unique properties including availability, high specific surface area, low cost, cation exchange capacity, and good removal efficiency. This paper reviews the recent progress made in the use of natural and modified clay minerals for the removal of antibiotics from water. First, the sources, occurrence, removal and health effects of the antibiotics commonly encountered in water bodies are described. Antibiotic concentration levels and average removal efficiencies measured in conventional activated sludge treatment systems worldwide are also provided to better address the problem. Second, the review explores the characteristics of clay minerals as adsorbent of antibiotics and the factors affecting the adsorption. The review identifies and discusses the future trends and strategies used to increase the adsorption capacity of clay minerals by modification and combination techniques (intercalation of novel functional groups such as organocations, biopolymers and metal pillared-clay minerals, combination with biochar or thermal activation). The quantitative comparisons of clay minerals' ability for antibiotic removal are given. Some natural clay minerals have good removal potential for antibiotics, with maximum adsorption capacities over 100 mg/g. For most other adsorbents, surface modifications and combination techniques resulted in improved adsorption properties (including higher surface area, enhanced adsorption capacity, increased stability and mechanical strength). Finally, the application of these adsorbents at pilot scale, using real wastewater samples, their reuse, economic analysis and life cycle assessment are other issues that have been considered. [Display omitted] • Clay minerals and modified clay minerals as adsorbents of antibiotics from water supplies. • Modification techniques using organocations, biopolymers or metal pillared-clays increase adsorption capacity. • Thermal treatment can be used to improve the structural properties of clays. • Experiments with real wastewater and pilot-scale studies are required. [ABSTRACT FROM AUTHOR]

The application of metal-organic frameworks (MOFs) Cu-BTC with good adsorption performance in wastewater treatment is limited due to its powder form. The high crystallinity Cu-BTC was compounded with agarose (AG) to obtain a porous foam-like composite Cu-BTC@agarose (Cu-BTC@AG). The Cu-BTC@AG is easy to recycle, the problem of difficult recovery when Cu-BTC is used in water treatment is well solved. In this paper, the influence of contact time, methylene blue (MB) initial concentration, adsorbent dosage, Na+ concentration, pH and temperature on the adsorption of MB by Cu-BTC@AG were studied systematically. Results showed that the adsorption amount of MB by Cu-BTC@AG increased with increasing of MB initial concentration, and the adsorption equilibrium was reached in 120 ​min. The solution pH ​= ​7 is favorable for Cu-BTC@AG to adsorb MB. In addition, the adsorption mechanism of MB on Cu-BTC@AG was further explored by isothermal adsorption model and adsorption kinetics model. The adsorption of MB on Cu-BTC@AG was well fitted with Langmuir isotherm and pseudo-second-order model. Maximum adsorption capacities of MB was 282.466 ​mg/g. The adsorption of MB was carried out through formation of a monolayer adsorption onto the homogeneous surface of Cu-BTC@AG. The adsorption behavior of MB on Cu-BTC@AG was analyzed by adsorption thermodynamics. The composite Cu-BTC@AG has a good quality and excellent removal efficiency for the dye methylene blue. The adsorption process is dominated by chemical adsorption. [Display omitted] • The composite Cu-BTC@AG is a promising adsorbent for removing of organic dye methylene blue from wastewater. • Porous foam-like composite Cu-BTC@AG is easy to separate from water. • The adsorption process was exothermic. [ABSTRACT FROM AUTHOR]

The paper presents the results of the studies on the vanadium (V) ions removal from the aqueous solutions in the adsorption process on biochars from different biomass types (cow manure BC1, wet distiller grains BC2, spent mushroom substrates BC3). The adsorbents were characterized by means of the SEM-EDS, FTIR, XRD and XPS techniques. The influence of adsorbent type and basic process parameters, such as pH and metal ion concentration in aqueous phase, adsorbent dose and time of contact of phases on the efficiency of V(V) was determined. Based on the obtained results, the mechanism and kinetics of the adsorption processes occurring on the biochar originating from the wet distiller grains as adsorbents with the greatest affinity for the V(V) ions were characterized, using isotherm models of Langmuir, Freundlich, Temkin and Dubinin-Radushkevich and pseudo-first-order, pseudo-second-order as well as intraparticle diffusion kinetic models. Under the constant process conditions (pH = 3.0; m = 0.5 g; c 0 = 50 mg/L) the order of V(V) ions removal from aqueous solutions was as follows: BC2 > BC1 = BC3. The biochar BC2 exhibited the maximum sorption capacity of 1.61 mg V(V)/g. The experimental kinetic data show the adsorption course according to the pseudo-second order model. [Display omitted] • Application of novel biochars for V(V) adsorption from aqueous solutions. • Physicochemical characterization of three biochars derived from different biomass. • Maximum adsorptivity (1.61 mg V(V)/g) of biochar originated from wet distiller grains. • Good correlation between experimental data and pseudo-second-order model. • Complex mechanism of V(V) ions removal confirmed by isotherms analysis. [ABSTRACT FROM AUTHOR]

Excess tetracycline produced by livestock and poultry breeding industry not only pollute the environment, but also enter the human body with the spread of the food chain, which will produce drug-resistant genes and threaten human health. In this paper, the adsoption of tetracycline from wastewater using iron oxide under microwave oxidation condition was explored. The effect of initial pollutant concentrations, the dosage of iron oxide, pH value, and temperature on the hybrid treatment process was investigated. Under the normal iron oxide and microwave oxidation conditions, when the dosage of iron oxide was 40 g/L and 30 g/L, pH was 10 and the temperature was 318 K, the removal rate of tetracycline was significantly improved. The adsorption of tetracycline by iron oxide under the two conditions conformed to the Freundlich isotherm model and pseudo-second-order dynamics model. In addition, the associated adsorption mechanism was unveiled. Under the microwave oxidation condition, the hot spot effect generated by the microwave oxidation effect would rapidly increase its surface temperature to form the active center and the electrostatic gravity to promote the reaction. The results indicated that microwave oxidation could promote the removal of antibiotics by iron oxide in livestock and poultry breeding wastewater. • Rising the amount of iron oxide, pH, solution temperature can boost the removal rate. • The tetracycline adsorption by iron oxide conforms to the Freundlich isotherm model. • The tetracycline adsorption by iron oxide suits pseudo-second-order dynamics model. • Microwave oxidation could promote the removal of antibiotics by iron oxide. [ABSTRACT FROM AUTHOR]

The scarcity of clean drinking water combined with other environmental and anthropogenic effects necessitates the demand for development of advanced technology for cleaning polluted water. Adsorption is one such technique that does not produce toxic byproducts and solves the problem of cleaning contaminated water at a lower cost. In recent years, magnetic composites, as adsorbent, have gained lot of attention due to their reusability which makes them sustainable and economical. This review article describes the challenges related to water quality, scarcity and then summarizes the current treatment technologies and advancement in the field of adsorption to resolve the prevailing concerns. The review includes an insight into the recent research being carried out in the field of magnetic composites and nanocomposites, as adsorbent, covering, probably, all aspects of what is going around the globe. Different materials, like polymers, biomaterials, clays and metal organic framework (MOF)-based magnetic composites and their applications in wastewater treatment processes have been included. The article is a comprehensive review on the application of different materials to detoxify various diverse pollutants with prime focus on magnetic composites. The thorough study of this review will surely bring upcoming researchers closer to the future possibilities of research in wastewater treatment. [Display omitted] • Water pollution is a global problem and only water remediation is the solution. •Around 100 recently published papers have been deeply analyzed and included. •Emphasis has been laid on magnetic composites synthesized during last five years. •Interactive mechanism has been included in the review. •Adsorption capacities at various conditions have been discussed vividly. [ABSTRACT FROM AUTHOR]

Permanganate (M n O 4 −) ions were adsorbed on the surface of MoS 2 nanosheet and then reacted with it. In this work, effects of pH, temperature, initial M n O 4 − concentration and ionic strength on this process were studied. The adsorption sites of MoS 2 were M o (I V) – S pairs located in its micropores (abbreviated as MI). Before starting reaction, MoS 2 acted as a high capacity adsorbent for M n O 4 − ions at a certain time. Under various conditions, M n O 4 − ions were adsorbed on the surface of MoS 2 during different time periods (20–180 ​min) and then reacted with it. The maximum adsorption capacity of M n O 4 − ions on MoS 2 surface in water at 328 ​K was 368.3 ​mg ​g-1 (2.33 ​mmol ​g-1). Adsorption isotherms were analyzed by the ARIAN model and it was recognized that in the pH range of 1–11, adsorption isotherms were composed from regions I and II and Δ H values of the process for regions I and II in neutral water were 31.4 ​kJ ​mol-1 and 9.9 ​kJ ​mol-1, respectively. At pH ​= ​12, adsorption isotherm was only formed from region I. In the pH range of 1–12, after completion of adsorption process, reaction of adsorbed M n O 4 − ions with adsorbent obeyed ARIAN–Hinshelwood mechanism. In the pH range of 1–11, water molecules and at pH ​= ​12, O H − ions and water molecules acted as nucleophiles, respectively. Finally, MoS 2 adsorbent was used for separation of C r 2 O 7 2 − and Ni2+ ions from M n O 4 − ions in water. [Display omitted] • MoS 2 is a high efficiency adsorbent for KMnO 4 and reacts with it. • Adsorption sites of MoS 2 for M n O 4 − ions were the Mo–S pairs located in its micropores. • The maximum adsorption capacity of MoS 2 for M n O 4 − ions in water was 368.3 ​mg ​g-1. • Mechanisms of adsorption and reaction of M n O 4 − ions were explained in the paper. [ABSTRACT FROM AUTHOR]

This work aims to apply carbon quantum dots (CQDs) from agriculture cellulosic waste (agro wastes), produced via an economically and eco-friendly single-step method, to be used into cellulose acetate composite microfibrous membranes as an innovative solution specifically designed to adsorb methylene blue (MB) and other cationic dyes that are present in various water effluents. Batch adsorption tests were conducted, with variations in contact time (1–24 h), initial MB concentration (25–300 ppm), and adsorbent doses (1–20 g/L). The maximum adsorption capacity of the membrane was 198 mg/g with an initial concentration of 300 ppm at 298 K. Thermodynamic parameters showed that the process is endothermic. Equilibrium experimental data for MB adsorption onto electrospun adsorbent were fitted using different isothermal models, with the Freundlich model showing the best fit. The pseudo-second-order model accurately described the kinetic data with high reliability (R2 > 0.99), and the calculated adsorption capacity was very close to the experimental data. N-CQDs loaded membranes were also tested for removing methyl violet and rhodamine B, demonstrating remarkably high dye removal efficiency. The underlying adsorption mechanism was also reported. Finally, it is worth mentioning that composite adsorbents can be efficiently applied to actual industrial cases because of the possibility of reusing them, opening the route to the fabrication of novel and highly performant adsorbents. These findings underscore N-CQDs' effectiveness in enhancing pollutant removal efficiency from wastewater, highlighting their environmental benefits and promoting a more sustainable approach to water treatment. Therefore, the prepared adsorbent, showing excellent adsorption performance, places them among adsorbents for practical applications in wastewater purification. [Display omitted] • Cellulose acetate/N-doped carbon quantum dots are successfully electrospun. • A novel system for adsorption of methylene blue was fabricated. • The effect of different parameters on the dye adsorption was investigated. • Removal efficiencies of rhodamine B and methyl violet were even evaluated. [ABSTRACT FROM AUTHOR]