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In this study, a simple method combining sol-gel and impregnation techniques was employed to synthesize magnetic Cu/MnFe 2 O 4. The resulting material demonstrated outstanding efficiency in removing mercury, achieving over 90% at reaction temperatures ranging from 150 °C to 200 °C. Through Cu incorporation, the Hg0 removal performance of Cu 0.15 MnFe was significantly enhanced, leading to a high adsorption capacity of 70.1 mg/g. This surpasses the capabilities of many previously reported adsorbents and holds great potential for enhancing the stability of Hg recovery efficiency. Furthermore, the presence of O 2 , HCl, and NO further improved the Hg0 removal. Conversely, H 2 O had an mild inhibitory effect on Hg0 removal. Additionally, the introduction of Cu noticeably mitigated the inhibitory impact of SO 2 on mercury removal characteristics and alleviated the issue of SO 2 poisoning in adsorbents. The primary active sites responsible for the oxidation of elemental mercury are the redox reaction between Cu2+/Cu+ and Mn3+/Mn2+, and adsorbed oxygen species. Through the oxidation process, Hg0 is primarily converted into various compounds, including HgO, Hg(NO 3) 2 , HgCl 2 , and HgSO 4. As a result, the prepared magnetic recyclable adsorbent, with its high mercury adsorption capacity, exhibits promising prospects for industrial application in the low-temperature removal of Hg0 from coal-fired flue gas. [Display omitted] • Magnetic Cu/MnFe 2 O 4 adsorbent was prepared using a simple method. • Cu/MnFe 2 O 4 owned a large Hg adsorption capacity of 70.1 mg/g. • The introduction of Cu greatly alleviated SO 2 poisoning in adsorbents. • Cu2+, Mn3+ and O* play a crucial role as active sites for Hg0 oxidation. [ABSTRACT FROM AUTHOR]

• A new phenomenon in converter transformer defined as fault-induced inrush current (FIIC) is proposed. • The generation mechanism and characteristics of FIIC are analyzed. • The characteristics of FIIC considering the HVDC control and protection are analyzed. • The effect of FIIC on differential protection for transformer is analyzed. • A countermeasure to avoid the influence of FIIC is proposed. Converter transformers are vital devices in line-commutated-converter (LCC) high-voltage direct-current (HVDC) systems. This paper introduces a new inrush current induced by a valve-side asymmetric ground fault on a converter transformer. It is defined as a "fault-induced inrush current (FIIC)." Taking a valve-side single-phase-to-ground (VSSPG) fault on a rectifier-side converter transformer as an example, the FIIC induced by this fault and its characteristics are first analyzed. Subsequently, the differences of the FIICs caused by the VSSPG faults occurring at the transformers in wye-grounded-wye (Y 0 /Y) and wye-grounded-delta (Y 0 /Δ) connections are discussed. After that, the effect of HVDC control and protection (C&P) on the characteristics of FIICs is considered. Finally, the impact of the FIIC on the transformer differential protection is analyzed. It is concluded that the transformer differential protection has a risk of being inappropriately blocked because of the FIIC. A suggestion for the HVDC C&P to apply a shorter protection action delay is proposed to reduce the risk. The theoretical analysis is verified through simulations performed in PSCAD/EMTDC. This study will be valuable for the research of inrush currents of converter transformers. [ABSTRACT FROM AUTHOR]