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[Display omitted] • Novel and recyclable ZIF-90@CS/SA hybrids were successfully synthesized. • Maximum adsorption capacity of Pb and Co by ZIF-90@CS/SA was 1.24 × 10−3 mol/g and 1.69 × 10−3 mol/g, respectively. • ZIF-90@CS/SA displayed remarkable stability in the elimination of Pb and Co. • Surface complexation and electrostatic attraction were primary interactive mechanisms. • Long-term field studies on Pb and Co behaviors in water medium were required. Efficient elimination of heavy metals contaminations can be extensively concerned by utilizing environmental-friendly adsorbents with pursuing high adsorption capacity and reducing the treatment costs of industrial sewage. Herein, the core–shell structured chitosan/sodium alginate polysaccharide polymers loading zeolite imidazolate framework-90 beads (ZIF-90@CS/SA) were successfully synthesized and analyzed to obtain efficient enrichment performances for Pb and Co. The ZIF-90@CS/SA beads were multifariously characterized through the superficial micropore structures, which included both before and after adsorption performance of Pb and Co from the macroscopical experiments. The optimal weight ratio of chitosan/sodium alginate was chosen 1:2 to prepare ZIF-90@CS/SA beads by drop-method, and then adsorption experiments of Pb and Co were also conducted under various water chemistry conditions. The especial adsorption equilibrium time for the elimination of Pb and Co through the ZIF-90@CS/SA beads was 2.5 h and 3.5 h respectively, which was in accordance with pseudo-second order pattern. The maximal adsorption capacity was respectively 1.24 × 10−3 mol/g for Pb and 1.69 × 10−3 mol/g for Co, which considerably improved in comparison with many previously reported adsorbents. The adsorption mechanisms of ZIF-90@CS/SA beads with Pb and Co were dominated by the surface complexation, ion exchange and electrostatic attraction. According to macroscopical experimental studies, the ZIF-90@CS/SA beads have promising applications in the field of sewage treatment with highly efficient enrichment, advantageous regeneration and purfication of numerous heavy metal contaminants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel and recyclable PGH/HDPA/PDA/MS hybrids were successfully synthesized. • Maximum adsorption capacity of Eu(III) and Cr(VI) by PGH/HDPA/PDA/MS was 2.43 × 10−3 mol/g and 6.75 × 10−3 mol/g, respectively. • PGH/HDPA/PDA/MS displayed remarkable stability in the elimination of Eu(III) and Cr(VI). • Surface complexation and reduction reaction were primary interaction mechanisms. • Long-term field studies on Eu(III) and Cr(VI) behaviors in medium were required. Synthesis and application of recyclable adsorbents with many available active sites and high adsorption capacity for accomplishing quick kinetics and high removal proportion have been become significant challenges in the purified fields of radionuclides and heavy metals contamination. Herein, regenerative ploy (guanidine hydrochloride hexamethylenediamine-phytic acid)-polydopamine decorated melamine sponges (PGH/HDPA/PDA/MS) were successfully synthesized using melted polymerization approach to remove Eu(III) and Cr(VI). The sorption behaviors and interactive mechanisms of Eu(III) and Cr(VI) by PGH/HDPA/PDA/MS were obtained via macroscopical experiments under various water chemistry factors conditions. The findings of our experimental studies demonstrated that specific sorption performances of Eu(III) and Cr(VI) onto PGH/HDPA/PDA/MS hybrids could achieve equilibrium within 3 h. The maximum adsorption capacities were respectively 2.43 × 10−3 mol/g and 6.75 × 10−3 mol/g for Eu(III) and Cr(VI), which were higher than large numbers of adsorbents reported among the anterior literatures. The interactive mechanism between PGH/HDPA/PDA/MS hybrids and Eu(III) and Cr(VI) was displayed through electrostatic attraction, cation exchange, surface complexation. Besides, the partially trivalent Cr(III) was also adhered to PGH/HDPA/PDA/MS surfaces through reductive reaction. According to our studies, the PGH/HDPA/PDA/MS hybrids are regarded as feasible adsorbents for highly effective purification of trivalent lanthanides and heavy metal ions pollutions from industrial wastewater. [ABSTRACT FROM AUTHOR]

In recent years, hazardous radionuclides and heavy metal ions contaminations in wastewaters have caused serious harm to the public and environment. Thus the application of remediation technology is more challenging. Herein, carboxymethyl cellulose supported magnetic graphene oxide composites (CMC/MGOs) are successfully synthesized using novel low temperature plasma technique. The SEM, TEM, XRD, FTIR, TGA and Raman spectra analysis can provide favorable evidence for the successful addition of CMC onto MGOs composite surfaces. The kinetics and isotherms of sorption of U(VI) onto CMC/MGOs composites can be excellently simulated by the pseudo-second-order kinetics model and the Langmuir model, respectively. The maximum capacity of CMC/MGOs composites for U(VI) calculated from the Langmuir model at pH 5.5 and 301 K is 7.94 × 10−4 mol/g. The experimental data indicate that uranium ions can interact with CMC/MGOs through inner-sphere surface complexation over the entire range of pH values. The experimental results suggest that CMC/MGOs composites can be regarded as potential adsorbent to remove uranium ions from wastewater systems. [ABSTRACT FROM AUTHOR]

In this study, the removal of radionuclide Co(II) from wastewater by Ca-rectorite was studied as a function of various environmental parameters such as contact time, pH, ionic strength, coexisting electrolyte ions, humic substances (HS) and temperature under ambient conditions. The results indicated that the sorption of Co(II) on Ca-rectorite was strongly dependent on pH and ionic strength. The Langmuir and Freundlich models were used to simulate the sorption isotherms of Co(II) at three different temperatures of 298.15, 318.15 and 338.15 K. The thermodynamic parameters ( $$ \Updelta H^{0} ,\,\Updelta S^{0} $$ and $$ \Updelta G^{0} $$) calculated from the temperature-dependent sorption isotherms indicated that the sorption process of Co(II) on Ca-rectorite was spontaneous and endothermic. At low pH, the sorption of Co(II) was dominated by outer-sphere surface complexation and ion exchange with Ca/H on Ca-rectorite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. From the experimental results, it is possible to conclude that Ca-rectorite has good potentialities for cost-effective disposal of radiocobalt bearing wastewaters. [ABSTRACT FROM AUTHOR]