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Anaerobic ammonium oxidation (anammox) is an efficient and economical nitrogen removal process for treating ammonium-rich industrial wastewaters. However, Cu(Ⅱ) and Ni(Ⅱ) present in industrial wastewaters are toxic to anaerobic ammonium-oxidizing bacteria (AnAOB). Unfortunately, the effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox have not been thoroughly investigated, especially when Cu(Ⅱ) and Ni(Ⅱ) coexist. This work comprehensively investigated the individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox and revealed the inhibitory mechanisms. With the influent NH 4 +-N and NO 2 −-N concentration of 230 and 250 mg L−1, the inhibition thresholds on anammox are 2.00 mg L−1 Cu(Ⅱ), 1.00 mg L−1 Ni(Ⅱ) and 1.00 mg L−1 Cu(Ⅱ) + 1.00 mg L−1 Ni(Ⅱ), and higher Cu(Ⅱ) or Ni(Ⅱ) concentrations resulted in sharp deteriorations of nitrogen removal performance. The inhibition of Ni(Ⅱ) on anammox was mainly attributed to the adverse effect on NiR activity, while the inhibition mechanism of Cu(Ⅱ) seemed to be unrelated to the four functional enzymes, but associated with disruption of cellular and organellar membranes. The behavior of extracellular polymeric substances (EPS) contributed to the antagonistic effect between Cu(Ⅱ) and Ni(Ⅱ) on anammox. In addition, the niche of Candidatus Brocadia and Candidatus Jettenia shifted under the Cu(II) and Ni(II) stress, and Candidatus Jettenia displayed greater tolerance to Cu(II) and Ni(II) stress. In conclusion, this research clarified the combined effect and the inhibitory mechanism of multiple heavy metals on anammox, and provide the guidances for anammox process application in treating high-ammonium industrial wastewaters containing heavy metals. [Display omitted] • The individual and combined effects of Cu(Ⅱ) and Ni(Ⅱ) on anammox are investigated. • The inhibition of Ni(Ⅱ) on anammox is attributed to the adverse effect on NiR activity. • The inhibition mechanism of Cu(Ⅱ) is unrelated to the four anammox functional enzymes. • EPS contribute to the antagonistic effect between Cu(Ⅱ) and Ni(Ⅱ) on anammox. • Heavy metals lead to a shift in the niches of Candidatus Brocadia and Candidatus Jettenia. [ABSTRACT FROM AUTHOR]

Engineering metal-organic-frameworks (MOFs) into flexible hybrid membranes has been endeavored to entrap various molecules through a conventional filtration process. In most cases, both the rejection ratio and adsorption capacity may be limited by a low MOF loading amount, polymeric coating barrier, or large flow flux. It remains challenging to achieve the combination of large-capacity adsorption, high flux and large rejection ratio in an individual filtration setup. Herein through an in-situ templating synthesis, nanofibers of zeolitic imidazolate frame work-8 (ZIF-8) with the distinct diameters of ~20 nm and ~100 nm were produced by coating on aramid nanofibrils and silk microfibrils, respectively. With the super loading amount of ZIF-8 up to ~70 wt%, these fibrous nanohybrids enabled to produce spider-web-like membranes with both the high rejection ratio (>99%) and large flow flux (up to ~390 L m-2 h-1 bar-1 at thickness of ~120 μm). Their superior adsorption capacities for organic dyes also ensured the maintenance of high rejection ratios at high flow flux for large-volume filtration. Thus, the template of two types of nanofibrils may offer a facile method to design web-like MOF membranes with hierarchical microstructures and to intercept a large amount of specific molecules through a continuous "one-pass" filtration process for practical applications. Image 1 • MOF nanohybrids were synthesized on aramid nanofibrils and silk microfibrils. • Flexible MOF membranes with spider-web-like microstructures were produced. • Both large flow flux and high reject ratio were achieved simultaneously. • Specific molecules were intercepted efficiently by a continuous "one-pass" process. [ABSTRACT FROM AUTHOR]