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The accumulation of mine tailings on Earth, generated from the extraction, processing, and utilization of mineral resources, is a serious environmental challenge. The importance of the recovery of valuable elements and rare-earth elements, together with the economic benefits of precious and base metals, is a strong incentive to develop sustainable methods to recover metals from tailings. Currently, researchers are attempting to improve the efficiency of valuable elements and rare-earth elements recovery from tailings using bioleaching, a more sustainable method compared to traditional methods. In this work, we report the research status of the application of Acidithiobacillus ferrooxidans (At. ferrooxidans) anaerobic reduction in tailings disposal. Recent advances in the anaerobic characteristics of At. ferrooxidans recovery process and technical difficulties are further described. We found that current research has made significant progress in anaerobic recovery. This is of great significance for the development of bioleaching technologies and industrial production of heavy metals in tailings. Finally, based on the perspectives and directions of this review, the present study can act as an important reference for the academic participants involved in this promising field. [ABSTRACT FROM AUTHOR]

Accumulating evidence suggests that severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) impairs the adaptive immune system during acute infection. Still, it remains largely unclear whether the frequency and functions of T and B cells return to normal after the recovery of Coronavirus Disease 2019 (COVID‐19). Here, we analyzed immune repertoires and SARS‐CoV‐2‐specific neutralization antibodies in a prospective cohort of 40 COVID‐19 survivors with a 6‐month follow‐up after hospital discharge. Immune repertoire sequencing revealed abnormal T‐ and B‐cell expression and function with large T cell receptor/B cell receptor clones, decreased diversity, abnormal class‐switch recombination, and somatic hypermutation. A decreased number of B cells but an increased proportion of CD19+CD138+ B cells were found in COVID‐19 survivors. The proportion of CD4+ T cells, especially circulating follicular helper T (cTfh) cells, was increased, whereas the frequency of CD3+CD4− T cells was decreased. SARS‐CoV‐2‐specific neutralization IgG and IgM antibodies were identified in all survivors, especially those recorded with severe COVID‐19 who showed a higher inhibition rate of neutralization antibodies. All severe cases complained of more than one COVID‐19 sequelae after 6 months of recovery. Overall, our findings indicate that SARS‐CoV‐2‐specific antibodies remain detectable even after 6 months of recovery. Because of their abnormal adaptive immune system with a low number of CD3+CD4− T cells and high susceptibility to infections, COVID‐19 patients might need more time and medical care to fully recover from immune abnormalities and tissue damage. [ABSTRACT FROM AUTHOR]

The electrocatalytic CO2 reduction reaction (CO2RR) to generate syngas (a mixture of CO and H2) is considered as one of the most effective routes to peak C and C neutrality. However, it is challenging to regulate the CO/H2 ratio by adjusting the activity of CO2RR. To address this problem, transition metals were designed to be encapsulated in C shells and loaded onto N‐doped C (NG) substrate catalysts for CO2RR generation of syngas. Comparative electrochemical tests revealed that Fe and Ni nanoparticles supported on N‐doped C matrix (denoted as Fe/NG and Ni/NG) produce CO/H2 in a wide range of relative ratios, thereby limiting their application in real industrial production. In contrast, Fe−Ni alloy nanoparticle supported on NG matrix (denoted as Fe2Ni/NG, where the subscript represents the molar ratio of the Fe source to Ni source) catalysts containing both Fe and Ni with a molar ratio of 2 : 1 exhibit high syngas evolution (1.2–2.9), suitable for typical downstream thermochemical reactions. The results provide a useful case for nonprecious metals to retain CO2RR, maintaining high activity while flexibly regulating the CO/H2 ratio. [ABSTRACT FROM AUTHOR]

Arsenopyrite (FeAsS) and realgar (As4S4) are two common arsenic minerals that often cause serious environmental issues. Centralised treatment of arsenic-containing tailings can reduce land occupation and save management costs. The current work examined the remediation schemes of tailings from Hunan Province, China, where by different tailings containing arsenopyrite and realgar were blended with exogenous slag zero valence iron (ZVI). Introducing Fe-oxidising bacteria (Acidithiobacillus ferrooxidans) recreates a biologically oxidative environment. All bioleaching experiments were done over three stages, each for 7 days and the solid phase of all tests was characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and selective extraction analyses. The results showed that the mixture group reduced arsenic release by 72.9–74.7% compared with the control group. The addition of 0.2 g ZVI clearly decreased arsenic release, and the addition of 4.0 g ZVI led to the lowest arsenic release among all tests. The decrease of arsenic released from the tailings was due to the adsorption and uptake of arsenic by secondary iron-containing minerals and Fe–As(V) secondary mineralisation. The addition of large amounts of ZVI reduced the arsenic detected in the amorphous Fe precipitates. Therefore, a low cost and integrated strategy to reduce arsenic release from tailings is to mix two typical tailings and apply exogenous slag ZVI, which can apply to the in situ remediation of two kinds or more arsenic-containing tailings. [ABSTRACT FROM AUTHOR]