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[Display omitted] • The magnetic nanoadsorbent with specific core-shell structure was synthesized. • Fe 3 O 4 @Carbon@ZIF-8 showed excellent adsorption capacities for Congo red and Cu(II). • The good adsorption ability was attributed to abundant active sites from ZIF-8. • Fe 3 O 4 @Carbon@ZIF-8 can selectively remove CR and Cu(II) from complex wastewater. • Nanoadsorbent's good stability and reusability indicated its practical application. Efficient and convenient removal of organic dyes and heavy metals from complex wastewater is still a challenge for human health and ecosystem remediation. Novel adsorbent, Fe 3 O 4 @Carbon@ZIF-8 with specific core-shell structure was synthesized by layer-by-layer self-assembly. The hydrophilic carbonaceous shell acts as both a linker and stabilizer between Fe 3 O 4 and ZIF-8. The characteristics of self-made adsorbent were comprehensively identified by numerous characterization methods. The adsorption kinetics, isotherms and the influence of various reacting parameters on its adsorption capacity of Congo red (CR) and Cu(II) were systematically investigated. Compared with other reported adsorbents, the maximum adsorption capacities of Fe 3 O 4 @Carbon@ZIF-8 towards CR (806.45 mg g−1) and Cu(II) (234.74 mg g−1) were much higher. Moreover, the adsorption process followed pseudo-second-order kinetics and Langmuir isotherm models. Selective adsorption of CR was investigated in the presence of cationic and anionic dyes, and the same as Cu(II) in the existence of competitive ions, which revealed that it was appropriate for selective adsorption toward CR and Cu(II) in complex wastewater. On the basis of FT-IR and XPS analyses, electrostatic interaction, hydrogen bonding, π-π bonding and ion exchange were involved in the mechanism of adsorption. Fe 3 O 4 @Carbon@ZIF-8 is suitable for practical application because of its good stability and reusability. [ABSTRACT FROM AUTHOR]

Magnetic separation technology is an efficient and feasible way to achieve rapid recovery of adsorbents, thus, the use of magnetic adsorbents has attracted the attention of many researchers. However, currently reported magnetic adsorbents have limited adsorption capacity due to insufficient adsorption sites and reactive groups. In this work, a novel magnetic chitosan-based amphiphilic adsorbent (PFSC) was synthesized by using UV-light irradiation method to combine with acryloyloxyethyl dimethylbenzyl ammonium chloride (AO), a molecule containing benzyl groups. PFSC and its precursors were carefully characterized, and their adsorption performances for the removal of anionic dyes were explored. The characterization results showed that the magnetic copolymers with a type of microsphere structure were successfully synthesized. Moreover, PFSC exhibited superior adsorption efficiency and pH resistance compared to those of an unmodified chitosan-based magnetic adsorbent (FSC). The maximum adsorption capacities of PFSC towards orange II (OG), acid red 88 (AE) and red amaranth (RM) were 955.0, 1075.8 and 567.5 mg/g at pH 3.0, respectively. The adsorption kinetics and isotherms of PFSC were consistent with that of a pseudo-second order kinetic model and the Langmuir isotherm model. In addition, adsorption-desorption experiments showed that PFSC could be rapidly separated and efficiently recycled even after 4 uses. More importantly, the FTIR and XPS results revealed that electrostatic adsorption and π-π stacking interactions were the main adsorption mechanisms for the PFSC-enhanced removal of anionic dyes. [Display omitted] • The chitosan-based amphiphilic magnetic copolymer was successfully synthesized by the UV-light initiated method. • The novel magnetic copolymer can be easily separated from solution by magnetic force. • The enhanced electrostatic adsorption and π-π stacking effect played an important role in the removal of anionic dyes. • The novel magnetic copolymer can be reused by simple acid-alkali adjustment. [ABSTRACT FROM AUTHOR]

[Display omitted] • PVA/PSSNa semi-IPN@Ni foam removes 95.17% CIP and 99.20% Ni(II) from wastewater. • Satisfactory adsorption occurs under neutral to slightly acidic pH (3–7). • In the binary system, Ni(II) greatly affects CIP adsorption, while CIP slightly affects Ni(II). • The interactive term of Ni(II) concentration and pH notably affects the CIP removal. • Removal of CIP and Ni(II) is most affected by their own concentration and pH. The coexistence of antibiotics and heavy metals in wastewater notably influences their adsorption removal behavior. However, the synergistic and antagonistic characteristics and mechanisms of their co-adsorption remain unclear. A novel adsorbent, PVA/PSSNa semi-IPN@Ni foam, was synthesized and applied to study its features and mechanisms in the single and binary systems of ciprofloxacin (CIP) and Ni(II). Exceptional removal efficiencies of 95.17 % for CIP and 99.20 % for Ni(II) were achieved. The interactive effects between CIP and Ni(II) were comprehensively explored through adsorption capacity ratio (Rq) and response surface methodology. Mechanistic insights were obtained through NaCl charge shielding experiments, substructure analog molecule probes experiments, theory calculations, as well as FTIR and XPS characterizations. The outcomes suggest that in the single system of CIP, the adsorption mechanisms include electrostatic attraction, hydrogen bonding, and π-π interactions. In the single system of Ni(II), mechanisms include electrostatic attraction and coordination. In the binary system of CIP + Ni(II), low Ni(II) concentrations facilitate CIP adsorption through coordination and bridging, whereas high Ni(II) concentrations let to competition for adsorption sites. Interestingly, the presence of CIP had minimal impact on Ni(II), exhibiting only a slight synergistic effect. These findings highlight the PVA/PSSNa semi-IPN@Ni foam as a hopeful candidate for removing CIP and Ni(II) from wastewater, and contribute to a deeper comprehension of synergistic and antagonistic mechanisms in the binary system involving CIP and Ni(II). [ABSTRACT FROM AUTHOR]

Environmentally friendly magnetic sodium alginate beads with glutaraldehyde cross-linking catalyzed by acetic acid-hydrochloric acid were successfully designed (FSSi@SA), and the magnetic bio-sorbents after amide reaction (FSSi@SA-sula) were utilized to absorb fluoroquinolone antibiotics in water. After amidation, FSSi@SA-sula exhibited strong pH adaptability (pH = 6.0–12.0). Langmuir and pseudo-first-order models can better describe the isotherm and kinetic process well, respectively. Under the optimization conditions with pH = 7 and temperature of 318.15 K, the maximum adsorption capacities of FSSi@SA-sula on the third-generation FQs ciprofloxacin (CIP) and the fourth-generation FQs moxifloxacin (MOX) respectively reached 365.66 and 149.57 mg g−1. The thermodynamics research indicated that the as-prepared FSSi@SA-sula is spontaneous and feasible. And after five adsorption cycles, the loss of adsorption capacity was less than 20% for both CIP and MOX, demonstrating the fine reusability and stability of the designed magnetic bio-sorbent. This study provides some ideas for facile synthesis of acid-catalyzed sodium alginate-glutaraldehyde cross-linking, which has promising applications in grafting various types of groups onto the retained carboxyl groups of sodium alginate spheres for the various contaminants removal in wastewater. [Display omitted] • FSSi@SA-sula beads were prepared by acid-catalyzed glutaraldehyde cross-linking. • FSSi@SA-sula showed excellent adsorption and reusability for CIP and MOX. • Langmuir and pseudo-first-order models better fitted adsorption process. • The mechanisms include electrostatic interactions, hydrogen bonding and n-π EDA. • Provided new ideas for facile synthesis of functional sodium alginate adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • La 2 (CO 3) 3 /CoFe 2 O 4 /biochar (LCB) was synthesized by a hydrothermal process. • LCB/PMS system was established to remove P(III) in one step. • LCB/PMS exhibited satisfactory removal rate of P(III) in a wide pH range. • SO 4 •- played a critical role in the oxidation process. • Different types of phosphorus could be rapidly removed by LCB/PMS. Phosphite [P(III)], an emerging eutrophication pollutant, has attracted limited attention in recent years. Owing to the higher solubility and resistance to biotransformation of P(III), oxidation of P(III) to phosphate [P(V)] is considered to be necessary to enhance P(III) removal. Herein, an efficient and regenerable magnetic La 2 (CO 3) 3 /CoFe 2 O 4 /biochar composite (LCB) was constructed through a facile one-pot hydrothermal method to treat phosphite-laden wastewater. LCB coupled with peroxymonosulfate (PMS) exhibited satisfactory P(III) removal performance through a one-step process for simultaneous oxidation and adsorption of P(III). The adsorption capacity of LCB/PMS for P(III) (71.94 mg/g) was much higher than that of LCB. LCB/PMS system showed high P(III) removal efficiency of 96.62 %, wide pH ranging from 4.0 to 9.0, and good reusability. It also worked well in the existence of anions and humic acid. The quenching experiments and electron spin resonance tests (ESR) revealed the critical role of SO 4 •- in the P(III) oxidation process. Characterization results demonstrated that electrostatic attraction and ligand exchange were responsible for P(III)/P(V) adsorption. Moreover, LCB/PMS system presented desirable performance in eliminating a series of typical organic and inorganic phosphorus. The LCB/PMS system provides a promising and sustainable technology for the purification of P(III)-contaminated water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Magnetic alginate-based biosorbents are prepared by free radical polymerization. • FSSEB-20 shows excellent adsorption capacities for DS and X-3B, respectively. • FSSEB-20 still shows satisfactory recycling rate after five runs. • The mechanism includes electrostatic action, hydrogen bonding and π-π interaction. In this work, we unveiled a novel magnetic biosorbent, poly (Benzyldimethyl[2-[(2-methyl-1-oxoally) oxy] ethyl] ammonium chloride)-immobilized magnetic sodium alginate composite-20 (FSSEB-20), and studied its adsorption behavior for two groups of toxic anionic organic pollutants, DS and X-3B from simulation wastewater. Results demonstrated that the Langmuir model could well describe the adsorption behavior of DS and X-3B on FSSEB-20, the maximum adsorption capacity of FSSEB-20 towards DS and X-3B are 340.58 mg g−1 and 370.85 mg g−1, respectively; according to kinetic results, the adsorption processes of both DS and X-3B on FSSEB-20 followed the pseudo-second-order kinetic model. To test the reusability of FSSEB-20, five runs of regeneration tests were performed. The removal rates of FSSEB-20 towards DS and X-3B are more than 74%. In addition to these, the surface interactions between FSSEB-20 and DS/X-3B were systematically analyzed based on the characterization results of FT-IR and XPS, which provided significant insights into the interactions between biosorbents and pollutants in wastewater. The mechanism of DS and X-3B adsorption by FSSEB-20 includes electrostatic interaction, hydrogen bonding and π-π interaction. Furthermore, this study also provides a new enlightenment for expanding the treatment of pollutants in wastewater with sodium alginate-based magnetic biosorbent. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel floating-separation adsorbent (APHGS-g-P(AMPS)) was designed and synthesized. • APHGS-g-P(AMPS) showed outstanding self-floating separation ability. • APHGS-g-P(AMPS) with satisfactory adsorption capacity was rich in –OH, –NH 2 and -SO 3 -. • The electrophilic addition strategy facilitated the grafting of P(AMPS) polymerized chains. • The sulfonic acid group exhibited excellent universal adsorption for MB and Pb(II). Inferior solid–liquid separation behavior and inadequate adsorption capacity are the main bottlenecks of current wastewater treatment adsorbents, especially in the purification of wastewater containing dyes and heavy metals. Accordingly, a novel floating separation adsorbent with polymeric chain structure, hollow glass sphere-g-(3-aminopropyl) triethoxysilane-g-poly(2-acrylamide-2-methyl-1-propanesulfonic acid) (APHGS-g-P(AMPS)), was fabricated through an electrophilic addition post-grafting strategy. The obtained APHGS-g-P(AMPS) exhibited satisfactory adsorption for methylene blue (MB) and lead ion (Pb(II)), as well as efficient flotation. Adsorption behavior analysis showed that the Pseudo-second-order kinetic model and Langmuir isotherm model were suitable for describing the adsorption process, and the maximum adsorption capacities for MB and Pb(II) were 249.33 and 345.93 mg·g−1 (313.15 K), respectively. Analysis of the adsorption mechanism indicated that the sulfonic acid group exhibited excellent universal adsorption for MB and Pb(II), which played a crucial role in the adsorption process. Furthermore, the efficient grafting of P(AMPS) polymerized chains onto the adsorbent was the pivotal factor to enhance adsorption. This study provided an efficient electrophilic addition post-grafting strategy for the structural design and functional modification of floating separation adsorbents. The results of this study are expected to have positive implications for the efficient purification of dyes and heavy metals wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-floating cyclodextrin-modified polymer was prepared. • The adsorption performance of TFCD and FTFCD was compared. • FTFCD simplified the recycling process by wrapping a hollow glass microsphere. • Porous structure and hydrophobic cavity favor the dye adsorption. • Polymers exhibited excellent selectivity toward cationic dyes. The separation and recycling processes of current cyclodextrin (CD)-based adsorbents are complicated. Thus, a novel composite based on a large surface area, porous, and self-floating tetrafluoroterephthalonitrile (TFN)-crosslinked CD polymer (FTFCD), was fabricated, characterized and applied to treat cationic dye pollutants. The characterization showed a porosity, good thermal stability, a stable crystal structure, and abundant functional groups on the prepared FTFCD, which had demonstrated great improvement on its adsorption capacity towards attention grabbing pollutants. The removal efficiency of the adsorbents for malachite green (MG) remained above 95% at pH 1 ∼ 10. In addition, the adsorbents were found to rapidly reach equilibrium governed by the pseudo-second-order kinetic model, and the maximum adsorption capacity of FTFCD was 1390.263 mg/g, as corroborated by the Langmuir isotherm model. While the phenolate groups of FTFCD found to electrostatically interacts with the MG strong cationic quaternary amine group, hydrogen-bonding was responsible for the hydroxyl group of FTFCD and the quaternary amine group binding. Meanwhile, the triangular cone configuration of MG makes it easy to be entrapped and absorbed in the hydrophobic cavity. Besides, after regeneration of exhausted FTFCD for five successive cycles, the MG removal efficiency still reached more than 80%. Thus, FTFCD could be applied as a potential alternative adsorbent for cationic dye removal owing to its excellent adsorption performance, convenient recycling, wide pH application, and environmental friendliness. [ABSTRACT FROM AUTHOR]