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Calcium alginate encapsulated Ni/Fe bimetallic nanoparticles beads (CA–Ni/Fe beads) were synthesized to simultaneously remove Cu (II) and monochlorobenzene (MCB) from aqueous solution. SEM, EDS, and XRD analyses confirmed that Ni/Fe bimetallic nanoparticles were not oxidized and successfully encapsulated by calcium alginate (CA). The experiments showed that the encapsulation process improved the simultaneous removal efficiency of Cu (II) and MCB, from 83.9% to 86.7% for Cu (II) and 94.7% to 99.1% for MCB compared with bare Ni/Fe nanoparticles after 120 min treatment. Furthermore, the removal efficiency of Cu (II) and MCB increased with higher temperature, calcium alginate: Ni/Fe ratios and pH. Pseudo-second-order model for adsorption and pseudo-first-order model for the reduction process fitted the simultaneous removal of Cu (II) and MCB using CA–Ni/Fe beads. Based on the above results, it could be concluded that the simultaneous removal was a two-step process: firstly, the adsorption of Cu (II) and MCB on the CA–Ni/Fe beads; and secondly, reduction of Cu (II) and dehalogenation of MCB by Ni/Fe in CA–Ni/Fe beads. Finally, the efficiency of regenerated CA–Ni/Fe beads was tested using synthesized wastewater which showed a satisfactory removal efficiency of Cu (II) and MCB maintained at 83.8% and 91.7% after three times’ regeneration. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fe nanoparticles (Fe NPs) were synthesized by tea extracts. [•] Fe NPs as the catalyst were used for Fenton-like oxidation of monochlorobenzene. [•] The oxidation of MCB and the removal of COD were 81.15% and 31.01%, respectively. [•] The mechanism for Fenton-like oxidative mechanism was proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] ZnO/ZnAl2O4 microspheres were prepared from LDH precursor spray-dried microspheres. [•] A preferential photodegradation on MO of the MB/MO mixture was observed. [•] Acidity of ZnO/ZnAl2O4 underlies preferential photodegradation. [ABSTRACT FROM AUTHOR]