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The biogeochemistry of iron (Fe) could affect arsenic (As) fate and change its availability. Fe(II) oxidation mediated by Fe oxidizing bacteria (FeOB) has the potential for As contamination remediation due to the formation of biogenic minerals. However, microbial Fe(II) oxidation coupled with the immobilization of As and the effect of FeOB on As remediation in soils has not been thoroughly investigated. In this study, a FeOB was isolated from a paddy soil and identified as Ochrobactrum sp. EEELCW01. The kinetics reactions were used to investigate how biological and chemical reactions were involved in the Fe(II)‐NO₃⁻‐FeOB system. Microbial Fe(II) oxidation coupled As mineralization, as well as its application in As contaminated paddy soils was studied. The results suggested that biological pathway contributed to the Fe(II) oxidation and NO₃⁻ reduction in the whole process, in which the chemical Fe(II) oxidation by biogenic NO₂⁻ was involved. Meanwhile, Fe(II) facilitated the reduction of NO₂⁻ while inhibited the reduction of NO₃⁻. Adding 2% or more bacteria led to a significant removal effect for aqueous As, resulting in the formation of lepidocrocite and two As‐containing minerals (angelellite, loellingite). With the simultaneous application of FeOB and NO₃⁻, the available As content in soils decreased by 37.6% and stabilized at 0.80 mg kg⁻¹ finally. In addition, the immobilization showed long‐term effect compared to the treatment with Fe(II) or NO₃⁻ alone. The study proved that the isolated FeOB had a significant ability for As mineralization and immobilization, which provided theoretical and application basis for the remediation of As contaminated soils.

Based on the discipline service of the library, this paper studies the composition of the discipline service ecology of universities, and believes that the discipline service ecology of universities is a dynamic and open system. It is proposed that building a healthy and harmonious discipline service ecology is the basis for universities to continue to carry out discipline services. It also analyzes the thinking, consciousness and ability necessary for building a good discipline service ecology, and makes a theoretical discussion for the creative development of discipline service.

Smelting activities pose serious environmental problems due to the local and regional heavy metal pollution in soils they cause. It is therefore important to understand the pollution situation and its source in the contaminated soils. In this paper, data on heavy metal pollution in soils resulting from Pb/Zn smelting (published in the last 10 years) in China was summarized. The heavy metal pollution was analyzed from a macroscopic point of view. The results indicated that Pb, Zn, As and Cd were common contaminants that were present in soils with extremely high concentrations. Because of the extreme carcinogenicity, genotoxicity and neurotoxicity that heavy metals pose, remediation of the soils contaminated by smelting is urgently required. The primary anthropogenic activities contributing to soil pollution in smelting areas and the progressive development of accurate source identification were performed. Due to the advantages of biominerals, the potential of biomineralization for heavy metal contaminated soils was introduced. Furthermore, the prospects of geochemical fraction analysis, combined source identification methods as well as several optimization methods for biomineralization are presented, to provide a reference for pollution investigation and remediation in smelting contaminated soils in the future.

Heavy metals (HMs) pollution is a universal and complex problem at lead smelting sites. Further understanding on the distribution, coexistence relationship and occurrence form of multi-metals in soils should be taken prior to restoration on the contaminated sites. In this study, 222 soil samples in a typical abandoned lead smelting site were investigated to understand the spatial distribution and geochemical partitioning of HMs. The results showed that soil quality was seriously threatened by As, Pb and Cd, which expressed high spatial heterogeneity. Integration of sequential extraction, X-ray photoelectron spectroscopy and mineral liberation analysers were employed to qualify the geochemical partitioning of HMs. The data showed that Pb and As were mainly partitioned in the reducible phase and residue phase, where the maximum of As were 18% and 79%, and the maximum of Pb were 31% and 64%, respectively, whilst Cd was mainly partitioned with residue phase (about 25%) and weakly acid soluble phase (about 18%). Paulmooreite was the major important mineral host for Pb and As, whereas Cd predominantly existed in willemite. These minerals containing HMs could usually with Fe reside in the octahedral layer of clay minerals such as montmorillonite, and may also reside in the interlayer. Quartz, montmorillonite and goethite were closely associated with HMs minerals in contaminated soils, which limited vertical migration of HMs and potential risks to groundwater. The results enhanced the understanding of spatial distribution and occurrence behavior of HMs, whilst providing potential benefits to heavy metal stabilization and risks control at abandoned non-ferrous metal smelting sites.

The microbe-driven iron cycle plays an important role in speciation transformation and migration of arsenic (As) in soil-rice systems. In this study, pot experiments were used to investigate the effect of bacterial iron (Fe) reduction processes in soils on As speciation and migration, as well as on As uptake in soil-rice system. During the rice growth period, pH and electrical conductivity (EC) in soil solutions initially increased and then decreased, with the ranges of 7.4–8.8 and 116.3–820 mS cm−1, respectively. The concentrations of Fe, total As and As(III) showed an increasing trend in the rhizosphere and non-rhizosphere soil solutions with the increasing time. Fe concentrations were significantly positively correlated with total As and As(III) concentrations (***p

Vegetation restoration is one of the most effective measures to restore degraded ecosystem in mining wasteland. A field experiment was conducted to study the effects of some site treatments’ three different approaches on the benefits of selective vegetation in the manganese mine. Three different approaches included (1) exposed tailings, the control treatment (tailing site); (2) soil covering of 10-cm thickness (external-soil site), and (3) soil covering of 10-cm thickness, soil ameliorating (adding fowl dung), and seeding propagation of Cynodon dactylon (Linn.) Pers. (rehabilitation site). The results indicated that 18 herb species were taken from 8 families and 4 woody plants in three sites after 1 year. After 3 years, 29 species from 14 families were observed in 3 sites. Meanwhile, compared with tailing site, the plant species of rehabilitation site was more than tailing site, and the plant abundance of external-soil site was similar to rehabilitation site. It was worthy to be mentioned that the plant species of external-soil site and rehabilitation site had a better effect on the plant community coverage of herb layer as compared with tailing site. In summary, the plant species of rehabilitation site had the most species diversity and could be recommended as the ve-restoration modes in manganese tail wasteland.

Temporal changes in the concentrations of dioxin-like (DL) polychlorinated biphenyls (PCBs) in environmental and biological matrices in China are not well understood. We determined the DL-PCB concentrations in pooled serum samples from the general population of Weifang City, Shandong Province, China in 2011 (n = 305) and 2017 (n = 495). The total DL-PCB concentration was 3.48 ± 1.31 ng/g lipid (mean ± standard deviation) in 2011 and 2.82 ± 1.73 ng/g lipid (19% lower) in 2017, but the difference was not statistically significant (p = 0.347). The DL-PCB concentrations and toxic equivalent concentrations were much lower in the serum from Weifang residents than have been found in serum from the inhabitants of other parts of the world. The concentrations of most of the DL-PCB congeners followed different downward temporal trends, but the PCB-118 concentration was higher in 2017 than in 2011. The temporal changes in the PCB concentrations and compositions in the samples from the general population of Weifang indicated that there may a new source of unintentionally produced PCBs in Weifang.

Crustal thicknesses and Poissonʼs ratios in the Ordos block and surrounding regions were estimated by the use of the H – k stacking method on teleseismic receiver functions. The data came from 353 temporary and permanent seismic stations in 2006–2011. Results show that the crustal thickness and Poissonʼs ratio gently vary within the Ordos block, with an average of 41.3 km and 0.265, respectively, consistent with a felsic composition of the crust. Crustal thicknesses predicted on the basis of Airy isostasy are consistent with the estimated thicknesses, implying that the topography is approximately compensated. The reactivated portion of the North China Craton that has undergone Mesozoic–Cenzoic lithospheric thinning is also characterized by the thinning crust, while the Ordos block maintains normal crustal thickness and average crustal velocity. Inferred higher densities in the lower crust and the anti-correlation between Poissonʼs ratio and crustal thickness in the Ordos block may be the result from underplating of mafic magmas in the Precambrian. Around the Ordos block, the Paleoproterozoic khondalite zone in the northern edge has higher Poissonʼs ratio and thickened crust, which is consistent with the lower crust being of more mafic composition. The Weihe–Shanxi graben in the southeastern edge has mid-high Poissonʼs ratio, high heat flow and thinning crust, which is consistent with the known transtensional tectonic setting. In the Liupanshan thrust belt, along the southwestern edge of the Ordos plateau, significant variations in crustal thicknesses and Poissonʼs ratios occur on two sides. Besides a thickened crust, a concaved Moho implies horizontal shortening of this edge of the Ordos block due to its collision with the northeastern Tibetan Plateau. The structural differences between the eastern and western edges of the Ordos block reflect that the Ordos block is in tectonic stress environment of the western compression and the eastern extension.

Synergistic extraction of cerium(IV) from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester(HEH/EHP, HL) and Di-(2-ethyl hexyl) phosphoric acid (HDEHP, HA) as extractant was investigated. The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium(IV) was extracted into organic phase in the form of Ce(SO 4 ) 0.5 HL 2 A 2 . A cation exchange mechanism was proposed for the synergistic extraction of Ce(IV). The equilibrium constants and thermodynamic functions such as Δ G , Δ H, and Δ S were determined in the extraction of Ce(IV) from sulfuric medium using mixture of HEH/EHP and HDEHP.

[1] Crustal thicknesses and Poisson's ratios in the eastern Tibetan Plateau were estimated using the H-k stacking method on teleseismic receiver functions. The data came mainly from the regional seismic networks in 2006–2008. Results show that the crust thickens from east to west, with a thickness difference of ∼30 km. A sharp change of crustal thickness from 41.5 to 52.5 km is observed across the Longmen Shan. Crustal thickness predictions based on the Airy-type isostasy are consistent with the estimations from H-k stacking, implying that the topography is approximately compensated. The study area can be divided into three parts according to the Poisson's ratios: (1) the northern Songpan-Garze terrane and the western Qinling orogenic belt with low ratios (ν ≤ 0.26); (2) the southern Songpan-Garze terrane, the Sanjiang fold system, and the Sichuan Basin with high-to-intermediate ratios (0.27 ≤ ν < 0.30); and (3) the southwestern Yangtze platform with low to intermediate ratios (ν ≤ 0.27). Joint interpretation of the low average Vp values from deep seismic sounding profiles and the low Vp/Vs ratios from receiver function analysis favors the presence of felsic crust rather than significant volumes of partial melts in the northern Songpan-Garze terrane and the western Qinling orogenic belt. The junction of the Longmen Shan fault zone, the Xianshuihe fault zone, and the Anninghe fault zone has an ultrahigh Poisson's ratio (ν ≥ 0.30), which could be considered as an evidence of local partial melt. We propose that the eastward movement of upper and middle crustal material in the southern Songpan-Garze terrane is obstructed by the more rigid Sichuan Basin, resulting in strain accumulation along the Longmen Shan fault zone.

In order to raise awareness of CSD and reduce misdiagnosis, we study the manisfection and treatment of CSD with enlarged masses.A retrospective study was carried out among the 10 identified patients with CSD on the basis of compatible clinical presentation and confirmatory pathology results for CSD.All the 10 patient's first symptoms were masses at some part of the body, more common in the neck. The ratio was 5% at neck, 3% at armpit, 1% at upper, 1% at groin. Two patients had low heat, increased leukocyte and larger masses of more than 2 cm in diameter After surgical resection, and anti-inflammatory treatment. All the patients were cured after surgery and postoperative anti-inflammatory treatment, and there was no recurrence during the 7-year follow-up.If patients were diagnosed and treated timely, the prognosis will be good. For the cases with extremely enlarged lymphonodus, surgical operation followed by antimicrobial chemotherapy will be a effective treatment.

A modified glow-discharge apparatus for the preparation of carbon stripper foils is described. The effects of anode size and distance between the two electrodes in the cracking chamber on the uniformity of the carbon foils are determined. The applied method to measure the thicknesses of the carbon foils and the technique to slacken stripper foils are mentioned.