Electrochemical decomplexation is a common technique that is widely used in industrial wastewater treatment. Although much research has been conducted to improve the decomplexation efficiency of metal–organic complexes [e.g., Ni-ethylenediaminetetraacetic acid (EDTA)], the effects of the fundamental electrochemical reactor configurations in this technology are often underestimated. This research provides insights into the role of the reactor configuration in electrochemical decomplexation of Ni-EDTA through experiments and simulations. Degradation experiments were conducted at the same current density and flow rate in flow-by (FB) and flow-through (FT) electrochemical reactor configurations. The results show that the FT reactor gives a better removal rate (FB: 35%, FT: 46%) and that its energy consumption is half that of the FB reactor [approximately 207.78 (kW·h)/(kg Ni) less]. Experiments show that the stagnant and back-mixing zones for the FT configuration (D_z ​= ​0.062) are smaller than those for the FB configuration (D_z ​= ​0.205). This promotes mass transport in the reaction environment and decreases problems with the reactor performance. Computational fluid dynamics simulations showed that the velocity and potential distributions were both more even for the FT than for the FB configuration. This increases uniformity of mass transport and the current density distribution, produces less ohmic resistance, and greatly improves energy saving. These experimental and simulation results will enable Ni-EDTA electrochemical decomplexation to be achieved with low energy consumption and high efficiency by using appropriate reactor configurations.

The adsorbents–adsorbates interaction is critical for resourcelization in heavy metal wastewater treatment. Nevertheless, it is still indistinct to depict the impact of metal center effect on heavy metals removal performance in metal-organic frameworks (MOFs)-based adsorbents. Herein, a series of MOFs with different metal centers of Mg(II), La(III), and Zr(IV) are rationally designed, and the effect of electronic structure on the Sb(V) removal performance is systematically investigated. The obtained La-MGs achieve Sb(V) adsorption capacity of 897.6 mg/g, which is about 1.2 and 4.5 times above average than those of Zr-MGs and Mg-MGs, respectively. On account of more edge adsorption sites achieve, the sites utilization efficiency of La-MGs (92.1%) is much better than Zr-MGs (75.0%) and Mg-MGs (20.4%). Furthermore, density functional theory (DFT) calculations reveal that La-MGs are more active than Mg-MGs and Zr-MGs, owing to the lower adsorption energy, higher charge transfer, and stronger bonding interaction, which will promote the Sb(V) removal performance. The experimental results in practical water indicate that La-MGs effectively capture antimony at low concentration, reaching drinking water standard in samples from Ganjiang River. This study opens an avenue for atomic-level insight into high-efficient absorbents design for water treatment from electronic structure-modification of active centers.