Enhanced removal of nickel(II) from water by utilizing gel-type nanocomposite containing sub-5 nm hydrated manganese(IV) oxides
Enhanced removal of nickel(II) from water by utilizing gel-type nanocomposite containing sub-5 nm hydrated manganese(IV) oxides
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DOI：
10.1016/j.seppur.2022.121457
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Xiaolin Zhang
中科院分区：
文献类型：
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作者：
Zhuoyao Fang;Helan Wang;Kaizhen Zhang;Sikai Cheng;Xiaolin Zhang
• Sub-5 nm HMO was confined inside a gel-type ion exchanger N001 for Ni(II) removal. • The resultant HMO@N001 possessed more reactive terminal oxygen (-OH) than HMO@D001. • HMO@N001 exhibited enhanced adsorption capacity and affinity toward Ni(II). • The exhausted HMO@N001 was effectively renewed by dimethylglyoxime for cyclic use. Efficient decontamination of heavy metals from water remains an urgent and still challenging issue. Herein, a novel adsorbent HMO@N001 was prepared by the in-situ encapsulation of hydrated manganese(IV) oxides (HMO) NPs inside the gel-type cation exchanger N001. Owing to the < 5 nm swollen pores of the N001 host, the in-situ growth of HMO NPs was restricted to sub-5 nm level (with the average size of 4.65 ± 1.17 nm). As a comparison, HMO NPs inside the commercially available macroporous analogue HMO@D001 possessed the average size of 24.52 ± 5.07 nm. The sub-5 nm nature granted HMO@N001 higher proportion (56.7%) of the reactive terminal oxygen (Mn-OH) compared with HMO@D001 (42.7%), contributing to that the maximum adsorption capacities ( Q m ) of HMO@N001 (146.6 ± 2.8 mg/g) toward Ni(II) reached to ∼1.36 times the value of HMO@D001 (107.9 ± 7.6 mg/g). Common coexisting cations including Na + , Mg 2+ , and Ca 2+ mainly suppressed the electrostatic adsorption from the N001 host, while the inner-sphere complexation between Ni(II) and HMO NPs was little affected, as verified by the SEM-EDS analysis. The used HMO@N001 was effectively regenerated using 0.05 M dimethylglyoxime solution for cyclic utilization. In fixed-bed experiments, the effective treatment capacity of the HMO@N001 column reached up to ∼4200 bed volume (BV), over 1.35 times that of the HMO@D001 column (∼3100 BV). This study may provide a promising option for advanced heavy metals decontamination.
