Search

• Multifunctional magnetic composite nanoparticles were facilely prepared. • The as-prepared FS@CS-PAA showed excellent adsorption capacities for cationic dyes. • FS@CS-PAA exhibited satisfactory removal rates for metal ions in a wide pH range. • The good adsorption ability was attributed to abundant active sites from CS-PAA. • FS@CS-PAA's good stability and reusability facilitated its practical application. Wastewater containing highly toxic, non-biodegradable and carcinogenic organic dyes and metal ions has been regarded as a severe threat to ecological environment and human health. Thus, it is of great significance to develop an effective approach to purify this kind of wastewater. Herein, novel magnetic adsorbent FS@CS-PAA was facilely prepared by coating anionic polyacrylamide-modified chitosan (CS-PAA) on the surface of silica-combined Fe 3 O 4 (FS). The morphology, structure, physic-chemical and magnetic properties of as-prepared FS@CS-PAA were fully characterized by various characterization techniques. Its adsorption behaviors towards cationic dyes and metal ions were systematically investigated in single systems, binary systems, and model wastewater. FS@CS-PAA was proved to have superior adsorption capacities of 2330.17 and 1044.06 mg g−1 respectively for crystal violet and methylene blue at 318.15 K, much higher than other reported adsorbents. Besides, FS@CS-PAA exhibited a pH-independent adsorption capability for metal ions, as demonstrated in single systems and in metal ion-dye binary systems, thus it could be used to treat a variety of metal ion wastewaters with different pH values. Moreover, FS@CS-PAA could be effectively and easily regenerated by HCl solution after the treatments of both synthetic wastewater and model wastewater. As revealed in FTIR and XPS analyses, the adsorption mechanism was mainly attributed to the electrostatic interaction, hydrogen bonding, cation exchange and chelating effect. With its excellent adsorption capacity for cationic dyes, pH-independent adsorption capability for metal ions, easy separation ability, satisfactory stability and good reusability, FS@CS-PAA can become an ideal candidate for wastewater treatment. [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]

[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]