Liangxue-Qushi-Zhiyang Decoction Ameliorates DNCB-Induced Atopic Dermatitis in Mice through the MAPK Signaling Pathway Based on Network Pharmacology.

The traditional prescription of Liangxue-Qushi-Zhiyang decoction (LQZ) has been demonstrated to be efficacious in treating atopic dermatitis (AD), a chronic inflammatory skin disorder marked by intense itching, redness, rashes, and skin thickening. Nevertheless, there has been an inadequate systematic exploration of the potential targets, biological processes, and pathways for AD treatment through LQZ. The study objective was to evaluate the efficacy and possible mechanism of LQZ in AD mice. In our study, we identified the primary compounds of LQZ, analyzed hub targets, and constructed a network. Subsequently, the predicted mechanisms of LQZ in AD were experimentally studied and validated in vivo, as determined by network pharmacological analysis. A total of 80 serum components of LQZ were identified through ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS), among which 49 compounds were absorbed into the bloodstream. Our results indicated that LQZ targets six putative key factors in the MAPK signaling pathway, which play essential roles in AD, namely, EGFR, p-MAPK1/3, p-MAPK14, IL-1ß, IL-6, and TNF-α. We observed spleen coefficient, dermatitis scores, and ear thickness were all downregulated in 2,4-dinitrochlorobenzene (DNCB)-induced mice after LQZ treatment. Histological analysis of the dorsal and ear skin further revealed that LQZ significantly decreased skin inflammation, epidermal thickness, and mast cell numbers compared to the DNCB group. Our study demonstrated the effectiveness of LQZ in reducing epidermal and dermal damage in a mouse model of AD. Furthermore, our findings suggest that downregulating the MAPK signaling pathway could be a potential therapeutic strategy for the treatment of AD.

Biomineralization of uranium by Desulfovibrio desulfuricans A3-21ZLL under various hydrochemical conditions.

Uranium pollution in groundwater environment has become an important issue of global concern. In this study, a strain of Desulfovibrio desulfuricans was isolated from the tailings of acid heap leaching, and was shown to be able to remove uranium from water via biosorption, bio-reduction, passive biomineralization under uranium stress, and active metabolically dependent bioaccumulation. This research explored the effects of nutrients, pH, initial uranium and sulfate concentration on the functional groups, uranium valence, and crystal size and morphology of uranium immobilization products. Results showed that tetravalent and hexavalent phosphorus-containing uranium minerals was both formed. In sulfate-containing water where Desulfovibrio desulfuricans A3-21ZLL can grow, the sequestration of uranium by bio-reduction was significantly enhanced compared to that with no sulfate loading or no growth. Ungrown Desulfovibrio desulfuricans A3-21ZLL or dead ones released inorganic phosphate group in response to the stress of uranium, which associated with soluble uranyl ion to form insoluble uranium-containing precipitates. This study revealed the influence of hydrochemical conditions on the mineralogy characteristics and spatial distribution of microbial uranium immobilization products. This study is conducive to the long-term and stable bioremediation of groundwater in decommissioned uranium mining area.

Surface Engineering Design of Nano FeS@Stenotrophomonas sp. by Ultrasonic Chemical Method for Efficient U(VI) and Th(IV) Extraction.

Nano-FeS has great potential for use in the management of radioactive contaminants. In this paper, we prepared a FeS@Stenotrophomonas sp. composite material by ultrasonic chemistry, and it showed excellent removal of uranium and thorium from the solution. Through optimization of the experimental conditions, it was found that the maximum adsorption capacities for uranium and thorium reached 481.9 and 407.5 mg/g for a composite made with a synthetic ratio of 1:1, pH 5 and 3.5, respectively, for U and Th, and sonication for 20 min. Compared with those of FeS or Stenotrophomonas alone, the removal capacity was greatly improved. The results of a mechanistic study indicated that efficient removal of the uranium and thorium was due to ion exchange, reduction, and microbial surface adsorption. FeS@Stenotrophomonas sp. could be applied to U(VI) and Th(IV) extraction for radioactive water.

Comparative efficacy and safety of six photoelectric therapies for the atrophic acne scars: A network meta-analysis.

Objectives This network meta-analysis assessed the relative efficacy and safety of six common photoelectric therapies including 1064-nm neodymium-doped yttrium aluminum garnet (Nd: YAG), fractional carbon dioxide laser(FSCO2), fractional micro-plasma radiofrequency(Plasma), micro-needling fractional radiofrequency (MRF), 1550nm or 1540nm erbium-glass non-ablative fractional laser (NAFL) fractional erbium-doped yttrium aluminum garnet (Er: YAG). Methods A comprehensive search to identify relevant studies was conducted using four electronic databases. Outcome measures were extracted based on subjective and objective indexes, including the dermatologists' evaluation(DE), the patients' overall satisfaction(PS), VAS score, and Postinflammatory hyperpigmentation (PIH). Results Eleven published clinical research studies, involving 405 patients were included in this study. Ranking of DE from large to small is as follows: Nd: YAG, FSCO2, Er: YAG, Plasma, NAFL, MRF. In terms of PS, the rand from high to low can be described as follows: Er: YAG, Nd: YAG, FSCO2, Plasma, NAFL, MRF. In connection with the sequencing of adverse events, pain severity from slight to severe as follows: Er:YAG, Nd:YAG, FSCO2, NAFL, MRF, Plasma. The probability of having PIH are presented in order from lowest to highest as follows: MRF, Plasma, Nd: YAG, NAFL, Er: YAG, FSCO2. Conclusion FSCO2 remains the mainstream of potentially curative treatment, then again Nd: YAG and Er: YAG require greater efforts to prove their superior effectiveness. NAFL might be appropriate for mild and moderate improvement with its strengths of good tolerance while Plasma fits into patients with higher pain thresholds but an expectation of higher results. MRF has not given expression on absolute predominance for the present. Registration PROSPERO CRD42021242160 (available from https://www.crd.york.ac.uk/prospero).

Arsenic in groundwater of the Poyang Lake area (China): aqueous species and health risk assessment.

Arsenic is a pervasive pollutant in groundwater, affecting more than 100 million people in 50 countries, including China. Toxicological analysis of As is complicated because As exists in the environment in a variety of forms and redox states. Here, a thermodynamic equilibrium model was used to calculate As speciation, investigate pathways of As accumulation and assess the risk of adverse health effects from oral ingestion of dissolved As from shallow groundwater in the Poyang Lake area (China). The accumulation of As, Fe, and NH4+ in the studied shallow groundwater was found to be the result of the dissolution of As-containing Fe, and probably Mn, (oxyhydr)oxides under reducing conditions due to excess influx of organic matter into the shallow aquifer. Modeling showed that As(III), which is more toxic than As(V), predominated at nearly all sampling sites, regardless of redox conditions. Arsenic tends to accumulate in the highest concentrations as neutral species (As(OH)30, HAsO20) under Eh < 50 mV. In the lower reaches of the Ganjiang and Xiushui Rivers, an increased non-carcinogenic risk from oral ingestion of As from drinking water was observed. The elevated cancer risk was found to be present throughout the study area. The lower reaches of the Ganjiang and Xiushui Rivers that have been shown to have the highest risk of both non-carcinogenic and carcinogenic adverse health effects are associated with more toxic As(III) species. Given the As speciation and risk profile, it is recommended to introduce strategies to alter redox conditions in shallow groundwater by adopting safer irrigation practices and managing fertilizer applications to avoid the buildup of high As concentrations associated with adverse health effects.

Synergy of surface adsorption and intracellular accumulation for removal of uranium with Stenotrophomonas sp: Performance and mechanisms.

Uranium is well-known to have serious adverse effects on the ecological environment and human health. Bioremediation stands out among many remediation methods owing to its being economically feasible and environmentally friendly. This study reported a great promising strategy for eliminating uranium by Stenotrophomonas sp. CICC 23833 in the aquatic environment. The bacterium demonstrated excellent uranium adsorption capacity (qmax = 392.9 mg/g) because of the synergistic effect of surface adsorption and intracellular accumulation. Further analysis revealed that hydroxyl, carboxyl, phosphate groups and proteins of microorganisms were essential in uranium adsorption. Intracellular accumulation was closely related to cellular activity, and the efficiency of uranium processing by the permeabilized bacterial cells was significantly improved. In response to uranium stress, the bacterium was found to release multiple ions in conjunction with uranium adsorption, which facilitates the maintenance of bacterial life activities and the conversion of uranyl to precipitates. These above results indicated that Stenotrophomonas sp. Had great potential application value for the remediation of uranium.

Occurrence characteristics of uranium mineral-related substances in various environmental media in China: A critical review.

The high demand and extensive exploitation of uranium resources resulted in the ubiquity and high detection levels of uranium mineral-related substances in various environment media in China. The potential adverse effects of uranium mineral-related substances on environment and human health have received extensive attention. Therefore, we reviewed the occurrence and spatial distribution of uranium mineral-related substances in various basins and environmental media in China to obtain an overall understanding. We collected information from over 70 papers reporting the occurrence and distribution of uranium mineral-related substances in multiple environments and 183 articles on the genesis of uranium deposits in China from 2001 to 2021. Then the occurrence of uranium mineral-related substances and corresponding correlation in different basins, environmental media and depth ranges were compared in detail. And this review assessed the uranium mineral-related pollution in China based on various environmental quality standards of China, EPA and WHO, and proposed the priority uranium mineral-related heavy metals and radioactive substances based on cluster analysis. This review showed that there were obvious differences in the occurrence characteristics of various uranium mineral-related substances in different environmental media, especially in the surrounding environment of sandstone type and hard rock type uranium deposits. These results will guide us to tackle the challenge of uranium mineral-related pollution in China. The correlation analysis of uranium mineral-related pollutants in different environmental media and the identification of priority pollutants will also provide instructions for us to control uranium mineral-related pollution. Finally, we put forward a series of urgent and practical suggestions on risk management and control of uranium mining according to the current situation of uranium mining environment in China, which is of guiding significance for the realization of "green uranium mining".

[Antibiotic Pollution Characteristics and Ecological Risk Assessment in Jinjiang River Basin, Jiangxi Province].

The concentration and distribution characteristics of 27 antibiotics, including 8 sulfonamides, 9 quinolones, 4 tetracyclines, 4 macrolides, and 2 nitroimidazoles, in the surface water, groundwater, and wastewater of the Jinjiang River basin in Jiangxi province were determined using solid-phase extraction combined with ultra-performance liquid chromatography-tandem triple quadrupole mass spectrometry. The results showed that there was antibiotic pollution in the waters of the Jinjiang River basin. A total of 20 antibiotics were detected in the surface water, with a concentration range of 32.3-280 ng·L-1. There were 15 types of antibiotics detected in the groundwater, and the concentration range was 28.4-55.8 ng·L-1. Twenty-one types of antibiotics were detected in the wastewater, with a concentration range of 231-8.71×104 ng·L-1. A comparison with the concentrations of eight common antibiotics in rivers and lakes in China and abroad showed that the pollution level in the Jinjiang River basin was at a medium level. By comparing the concentrations of sulfamethoxazole in groundwater from domestic and international samples, the groundwater pollution in the Jinjiang River basin was clearly in the middle and lower range. A comparison of the concentrations of the three antibiotics in the aquaculture wastewater from domestic and abroad samples indicated that the pollution level of sulfadiazine in the aquaculture wastewater from the Jinjiang River basin was relatively high. The ecological risk assessment results showed that there were nine medium- and high-risk antibiotics, which were clarithromycin, erythromycin, ciprofloxacin, sulfathiazole, roxithromycin, tetracycline, ofloxacin, enrofloxacin, and sulfamethoxazole; the rest were low-risk or no-risk antibiotics.

Hydroxyapatite modified ZIF-67 composite with abundant binding groups for the highly efficient and selective elimination of uranium (VI) from wastewater.

In this work, nanoscale hydroxyapatite (HAP)-modified ZIF-67 composite, HAP/ZIF-67, with abundant functional groups for uranium(VI) binding was synthesized via a facile ultrasound-assisted synthesis method. The prepared HAP/ZIF-67 was characterized by XRD, SEM, TEM, BET, FT-IR and XPS techniques, and was applied to eliminate uranium(VI) from aqueous solutions under various conditions, i.e., pH, coexisting ions, temperature and contact time. The results indicate that the abundant Co-OH, -CN- and -NH- binding groups originating from the ZIF-67 and the Ca-OH and PO43- derived from loaded nanoscale HAP synergistically endowed HAP/ZIF-67 with the excellent U(VI) adsorption capacity of 453.1 mg/g, which is 2.55 and 1.78 times that of pristine HAP and ZIF-67. HAP/ZIF-67 showed high adsorption selectivity toward U(VI), and the U(VI) elimination efficiency for real wastewater by HAP/ZIF-67 reached 97.29%. The adsorption kinetics and isotherms were well simulated by the pseudo-second-order model and Langmuir isotherm model, respectively, suggesting that U(VI) adsorption was an endothermic monolayer chemisorption process. The adsorption mechanism of U (VI) by HAP/ZIF-67 was dominated by surface complexation process. This work is expected to provide an effective strategy for developing HAP-modified MOFs absorbent to be used for the highly efficient elimination of radionuclides from wastewater.

An overview of in-situ remediation for nitrate in groundwater.

Faced with the increasing nitrate pollution in groundwater, in-situ remediation has been widely studied and applied on field-scale as an efficient, economical and less disturbing remediation technology. In this review, we discussed various in-situ remediation for nitrate in groundwater and elaborate on biostimulation, phytoremediation, electrokinetic remediation, permeable reactive barrier and combined remediation. This review described principles of each in-situ remediation, application, the latest progress, problems and challenges on field-scale. Factors affecting the efficiency of in-situ remediation for nitrate in groundwater are also summarized. Finally, this review presented the prospect of in-situ remediation for nitrate pollution in groundwater. The objective of this review is to examine the state of knowledge on in-situ remediation for nitrate in groundwater and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. This helps to better understand the control mechanisms of various in-situ remediation for nitrate pollution in groundwater and the design options available for application to the field-scale.

Geochemical signatures of rare earth elements and yttrium exploited by acid solution mining around an ion-adsorption type deposit: Role of source control and potential for recovery.

Elevated concentrations of rare earth elements and yttrium (REE + Y) in acid mine drainage (AMD) attract worldwide attention. However, the source and control of REE + Y distribution patterns in AMD remain unclear. Water, rock, sediment, and sludge samples were collected from an ion-adsorption deposit site to investigate REE + Y concentrations and distributions. The heavy REE (HREE)-enriched patterns of the AMD resulted from preferential desorption of HREE in the clay-rich sediment strata, from which the REE + Y were ion-exchanged by an in-situ underground leaching process using ammonium sulfate brine. Free ions and sulfate complexes preserved REE + Y patterns and facilitated REE + Y mobility in the AMD leachate system. High concentrations of REE + Y occurred in the AMD, and decreased progressively through nitrification-denitrification and coagulation-precipitation procedures in a water treatment plant. Concentrations of REE + Y were one to three orders of magnitude higher in AMD than those in groundwater, and were negatively correlated (r2 = -0.72) with pH (3.8 to 8.7), suggesting that an acid desorption from minerals contributed the REE + Y to the AMD from the source rock. Normalized REE + Y patterns showed enrichments of HREE over light REE (LREE) and negative Ce anomaly. The distribution patterns were relatively constant for all water samples, despite their huge difference in REE + Y concentrations. This suggested a limited impact of preferential precipitation of LREE over HREE on REE + Y fractionations during neutralization. The potentially recoverable LREE and HREE were calculated to range between 1.12 kg/day and 3.37 kg/day, and between 1.29 kg/day and 3.76 kg/day, respectively. The findings reported in this study lend promise for efficient REE + Y recovery from AMD.

Nitrogen transformation and pathways in the shallow groundwater-soil system within agricultural landscapes.

The present study considers the behavior of nitrogen compounds in the shallow groundwater-soil system as necessary for the functioning of the nitrogen cycle within agricultural landscapes and one of the first steps of the formation of groundwater chemical composition. Data were collected in 2011-2018 within the Poyang Lake area (Jiangxi Province, China), where agricultural landscapes prevail. The soil and groundwater samples were taken in different periods of an agricultural season at the beginning of the agricultural season (spring) and after harvesting (autumn). The combined geochemical data on the chemical and microbiological composition of the soils and shallow groundwater and isotopic data on dissolved nitrate allowed researchers to resolve that nitrogen enters the system in the form of organic compounds, particularly, due to the soil fertilization at the beginning of the agricultural season. Organic nitrogen compounds transform into nitrate under the influence of nitrifiers in the soil before getting the shallow aquifer, where the occurrence of denitrification is suggested. Within the Ganjiang and Xiushui interfluve, reducing conditions, together with the formation of clay minerals from the aqueous solution, may serve a geochemical barrier for the accumulation of nitrogen compounds preventing the transformation of ammonium to nitrate and providing its sorption. It also should be noted that bacterial diversity in the shallow groundwater has a strong relation with the amount of nitrate in the system, whereas in the soil, it is connected with sampling depth.

Occurrence and Distribution of Uranium in a Hydrological Cycle around a Uranium Mill Tailings Pond, Southern China.

Uranium (U) mining activities, which lead to contamination in soils and waters (i.e., leachate from U mill tailings), cause serious environmental problems. However, limited research works have been conducted on U pollution associated with a whole soil-water system. In this study, a total of 110 samples including 96 solid and 14 water samples were collected to investigate the characteristics of U distribution in a natural soil-water system near a U mining tailings pond. Results showed that U concentrations ranged from 0.09 ± 0.02 mg/kg to 2.56 × 104± 23 mg/kg in solid samples, and varied greatly in different locations. For tailings sand samples, the highest U concentration (2.56× 104 ± 23 mg/kg) occurred at the depth of 80 cm underground, whereas, for paddy soil samples, the highest U concentration (5.22 ± 0.04 mg/kg) was found at surface layers. Geo-accumulation index and potential ecological hazard index were calculated to assess the hazard of U in the soils. The calculation results showed that half of the soil sampling sites were moderately polluted. For groundwater samples, U concentrations ranged from 0.55 ± 0.04 mg/L to 3.36 ± 0.02 mg/L with a mean value of 2.36 ± 0.36 mg/L, which was significantly lower than that of percolating waters (ranging from 4.56 ± 0.02 mg/L to 12.05 ± 0.04 mg/L, mean 7.91 ± 0.98 mg/L). The results of this study suggest that the distribution of U concentrations in a soil-water system was closely associated with hydrological cycles and U concentrations decreased with circulation path.

Assessment of heavy metals and arsenic pollution in surface sediments from rivers around a uranium mining area in East China.

Taking the surface sediments of rivers near a uranium mine in East China as the research object, the concentrations of seven metals, including Cr, Cu, Ni, Pb, Zn, Cd and As, were analyzed. The pollution degree and ecological risk of heavy metals and arsenic were evaluated according to the geo-accumulation index, pollution loading index, potential ecological risk index and sediment quality guidelines. Finally, the sources of pollution were determined by Pearson's correlation analysis, principal component analysis and hierarchical cluster analysis. The results indicated that Cr, Cu, Ni, Pb, Zn, Cd and As in sediments showed varying degrees of contamination, using the soil background value of the study area as a reference, and Cd was the main excessive pollutant in the sediments. In most parts of the river, Cd has reached a moderate level of pollution. The potential ecological hazards at sampling sites 9, 13, 17 and 18 are significantly higher than the other sites because of the impact of urbanization and uranium mining and smelting. Cu, Zn, Cr, Ni and Cd are mainly derived from urban activities and the uranium industry, Pb is mainly derived from vehicle emissions, and As is mainly derived from nature and rocks.

Effect of particle size on uranium bioleaching in column reactors from a low-grade uranium ore.

This study evaluated the effectiveness of ore particle size on column bioleaching from low-grade uranium ore using an indigenous Acidithiobacillus ferrooxidans, isolated from local uranium ore. The uranium content was 0.033% by weight and ore particle size was crushed to <50 mm, <30 mm, and <15 mm. The additive content of sulfuric acid 5 g/L, Fe3+ dosage of 5.0 g/L, spray strength of 2.57 L/(h·m2) and temperature of 25 °C were controlled. After 150 days of leaching, acid consumption amounted to 2.73 g H2SO4 per kg ore, the obtained maximum uranium extraction was 64.85% with the ore particle size of <15 mm. The results showed that a smaller particle size ore had a higher uranium extraction and that an economic uranium extraction can be obtained by correctly controlling the ore granularity.

Shallow groundwater quality and associated non-cancer health risk in agricultural areas (Poyang Lake basin, China).

Owing to their accessibility, shallow groundwater is an essential source of drinking water in rural areas while usually being used without control by authorities. At the same time, this type of water resource is one of the most vulnerable to pollution, especially in regions with extensive agricultural activity. These factors increase the probability of adverse health effects in the population as a result of the consumption of shallow groundwater. In the present research, shallow groundwater quality in the agricultural areas of Poyang Lake basin was assessed according to world and national standards for drinking water quality. To evaluate non-cancer health risk from drinking groundwater, the hazard quotient from exposure to individual chemicals and hazard index from exposure to multiple chemicals were applied. It was found that, in shallow groundwater, the concentrations of 11 components (NO3-, NH4+, Fe, Mn, As, Al, rare NO2-, Se, Hg, Tl and Pb) exceed the limits referenced in the standards for drinking water. According to the health risk assessment, only five components (NO3-, Fe, As, rare NO2- and Mn) likely provoke non-cancer effects. The attempt to evaluate the spatial distribution of human health risk from exposure to multiple chemicals shows that the most vulnerable area is associated with territory characterised by low altitude where reducing or near-neutral conditions are formed (lower reaches of Xiushui and Ganjiang Rivers). The largest health risk is associated with the immune system and adverse dermal effects.

Effect of Yupingfeng granules on the skin barrier in atopic dermatitis mice models.

OBJECTIVE: To investigate effect of Yupingfeng granules, prepared with Chinese Medicines, on the wound healing and on the expression of aquaporin 3 (AQP3) and the skin barrier in the animal models of atopic dermatitis (AD). METHODS: Acute skin lesions of AD models were prepared using 2,4-dinitrochlorobenzo (DNCB) in mice and animals were treated with either Yupingfeng granules or placebo for two weeks. Skin wound healing outcome was assessed by measuring skin thickness, weight (quality) of the skin, and trans-epidermal water loss (TEWL). Expression of AQP3 mRNA and protein was assessed by reverse transcriotion polymerase chain reaction (RT-PCR) and immunoblotting, respectively. RESULTS: Yupingfeng granule treatment resulted in significant acceleration of wound healing with 63.64% efficiency, which was significantly higher than that of placebo granule treatment (31.82%, P < 0.01 by Wilcoxon Rank-sum test). Skin thickness, weight of the wounded skin, and TEWL were significantly higher in the AD models compared to that of normal animals. Treatment with Yupingfeng granules resulted in significant decrease in skin thickness [(937 ± 31) vs (360 ± 21) urn, P < 0.01], weight of the wounded skin [(42 ± 4) vs (24 ± 5) mg, P < 0.01], and TEWL [(30 ± 4) vs (13 ± 4) g•h-1•m-2, P < 0.01]. Yupingfeng granules also significantly down-regulated mRNA and protein expression of AQP3 in the animal models. CONCLUSION: Our findings suggested that Yupingfeng granules could be used in AD treatment.

Sources and behaviour of nitrogen compounds in the shallow groundwater of agricultural areas (Poyang Lake basin, China).

Nitrogen contamination of natural water is a typical problem for various territories throughout the world. One of the regions exposed to nitrogen pollution is located in the Poyang Lake basin. As a result of agricultural activity and dense population, the shallow groundwater of this area is characterised by a high concentration of nitrogen compounds, primarily NO3-, with the concentration varying from 0.1mg/L to 206mg/L. Locally, high ammonium content occurs in the shallow groundwater with low reduction potential Eh (<100mV). However, in general, the shallow groundwater of the Poyang Lake basin has Eh>100mV. To identify sources of nitrogen species and the factors that determine their behaviour, the dual stable isotope approach (δ15N and δ18О) and physical-chemical modelling were applied. Actual data were collected by sampling shallow groundwater from domestic water supply wells around the lake. The δ18О values from -4.1‰ to 13.9‰ with an average value of 5.3 permille indicate a significant influence of nitrification on nitrogen balance. The enrichment of nitrate with the 15N isotope indicates that manure and domestic sewage are the principal sources of nitrogen compounds. Inorganic nitrogen speciation and thermodynamic calculations demonstrate the high stability of nitrate in the studied groundwater. Computer simulation and field observations indicate the reducing conditions formed under joint effects of anthropogenic factors and appropriate natural conditions, such as the low-level topography in which decreased water exchange rate can occur. The simulation also demonstrates the growth in pH of the groundwater as a consequence of fertilisation, which, in turn, conduced to the clay mineral formation at lower concentrations of aqueous clay-forming components than the ones under the natural conditions.

Column bioleaching of uranium embedded in granite porphyry by a mesophilic acidophilic consortium.

A mesophilic acidophilic consortium was enriched from acid mine drainage samples collected from several uranium mines in China. The performance of the consortium in column bioleaching of low-grade uranium embedded in granite porphyry was investigated. The influences of several chemical parameters on uranium extraction in column reactor were also investigated. A uranium recovery of 96.82% was achieved in 97 days column leaching process including 33 days acid pre-leaching stage and 64 days bioleaching stage. It was reflected that indirect leaching mechanism took precedence over direct. Furthermore, the bacterial community structure was analyzed by using Amplified Ribosomal DNA Restriction Analysis. The results showed that microorganisms on the residual surface were more diverse than that in the solution. Acidithiobacillus ferrooxidans was the dominant species in the solution and Leptospirillum ferriphilum on the residual surface.