Soil Microbial and Enzyme Activities Response to Pollution Near an Aluminium Smelter   总被引：2，自引：0，他引：2  

Juan Carlos García‐Gil  Jozef Kobza  Pedro Soler‐Rovira  Soňa Javoreková 《洁净——土壤、空气、水》2013,41(5):485-492

The aim of this research was to assess the impact caused by a long‐term pollution by fluoride and heavy metals in two soils (PS1 and PS2) near an aluminium smelter in Slovakia, on soil microbial biomass C (MBC), basal respiration, metabolic quotient (qCO₂) water‐soluble organic C (WSOC) and enzymes activities involved in the C, N and P biogeochemical cycles. An unpolluted soil was used as control (C0). Results obtained for soil fluoride content reflected a gradient of fluoride exposure in topsoils of contaminated sites. Decreases in microbial and enzymatic activities and in MBC to organic C ratio were found in PS2 site, which is closer to the smelter and exhibited the highest fluoride content. PS1‐soil showed an extreme alkaline pH caused by leaching of waste effluents from the smelter dumping site, higher contents of Zn, Cu, Pb and Cd, significantly larger MBC, qCO₂ and catalase and urease activities, and much larger basal respiration and dehydrogenase activity than PS2 and C0‐soil. Phosphatase, β‐glucosidase and BAA‐protease were negatively correlated with WSOC, basal respiration and dehydrogenase activity, and showed some degree of inhibition in polluted sites. These results may indicate different responses of microbial communities to ecosystem disturbances, caused by the drastic changes in soil's physicochemical properties as result of the long‐term emissions of fly ash with high levels of contaminants that are still affecting soil microbial and enzymatic activities.  相似文献   

Distribution of fluoride in surface water and a health risk assessment in the upper reaches of the Yongding River     

Wang  Tao  Shao  Zhijiang  Yu  Hui  Bah  Hamidou 《地理学报(英文版)》2020,30(6):908-920

The excessive exposure to high concentrations of fluoride in drinking water can lead to a serious disease called fluorosis. The upstream region of the Yongding River is an ecological protection area for Beijing. Some studies have reported that there is a high concentration of fluoride in the groundwater in this area. However, there are few data on the distribution of fluoride in surface water and health risk assessments in this area. In this study, the fluoride concentrations were determined by using the spectrophotometric method using data from 2013 to 2017 from 9 surface water quality monitoring stations in the upper reaches of the Yongding River. The health risks of fluoride were assessed using the approach developed by the United States Environmental Protection Agency(US EPA). The results indicated that the fluoride content in the drinking water ranged from 0.30 to 1.50 mg L~(-1), with an average of 0.86 mg L~(-1). In total, 22.7% of the analyzed samples exceeded the Chinese limit of 1.0 mg L~(-1) for fluoride, and 5.5% of samples had less than the permissible limit of 0.5 mg L~(-1). Higher fluoride concentrations and fluorosis hotspots were found to be predominately located downstream of the Yanghe River close to the Guanting Reservoir, where 71.4% of samples exceeded the limit of 1.0 mg/L~(-1). The spatial distribution of high fluoride concentrations was found to be primarily determined by industry. The hazard quotient(HQ) index for children, teenagers and adults indicated that 19.6%, 15.6%, and 5.1% of the samples in the upper reaches of the Yongding River, respectively, posed health hazards to the associated groups. Furthermore, the HQ index more than 1 for children, teenagers and adults had values of 64.3%, 56.1%, and 19.4%, respectively, in samples from the downstream region of the Yanghe River. Therefore, there are potential risks of dental and skeletal fluorosis in the upper river reaches of the Yongding River. It is imperative to take measures to reduce the fluoride pollution in surface water and control fluorosis. Action should be taken to improve the disposal of industrial waste.  相似文献   

南极大磷虾粉对点带石斑鱼幼鱼氟蓄积的影响     

黄艳青  龚洋洋  陆建学  高露姣  黄洪亮 《海洋科学》2015,39(6):32-38

为研究南极大磷虾(Euphausia superba)粉对点带石斑鱼幼鱼氟蓄积和生长的影响,作者通过饲养点带石斑鱼(Epinephelus malabaricus)幼鱼(初始体质量为(3.50±0.30)g,体长(5.5±0.3)cm)100 d,在基础日粮中添加0%(对照组)、2%、4%和6%的南极大磷虾粉制成4组饲料,饲料中氟质量分数分别为145.81、202.71、257.53和317.60 mg/kg。结果显示:南极大磷虾粉中的氟在点带石斑鱼幼鱼组织中的分布程度,以脊椎骨和鳃中为最高,氟质量分数分别为(58.020~114.380)mg/kg和(46.029~123.874)mg/kg,其次是皮(含鳞片)((44.127~88.761)mg/kg),再次是肝((7.654~18.248)mg/kg),而肌肉中氟蓄积最低((3.352~3.999)mg/kg);脊椎骨、皮(含鳞片)和鳃中氟含量随饲养时间的延续而产生蓄积,且与饲料中南极大磷虾粉的水平呈正相关,肝中氟含量随饲养时间延续而产生蓄积,但与南极大磷虾粉的水平无相关性,肌肉中氟含量与饲养时间和南极大磷虾粉水平均无相关性;100 d时,4%组和6%组的特定生长率处于最高水平,且显著高于对照组(P0.05)。本研究表明在饲料中添加4%~6%南极大磷虾粉,对点带石斑鱼幼鱼生长具有明显的促进作用。  相似文献   

The origin of fluoride in groundwater supply to Hermosillo City, Sonora, México   总被引：1，自引：0，他引：1  

L. Valenzuela-Vásquez  J. Ramírez-Hernández  J. Reyes-López  A. Sol-Uribe  O. Lázaro-Mancilla 《Environmental Geology》2006,51(1):17-27

Anomalous high fluoride concentration up to 7.59 mg/dm³ is found in groundwater from “La Victoria” area. This water is used to supply drinking water to Hermosillo City, Sonora. Geochemistry of groundwater, relationship between physicochemical parameters, hydrogeology and geologic setting were correlated to define the origin and the geochemical mechanisms of groundwater fluorine enrichment. High fluoride concentration is associated with high bicarbonates, pH and temperature, and it decreases toward the west and south of the area. Fluoride is in negative correlation to calcium concentration. Sodium sulphate facies of regional deep water flow are related to high fluoride concentration. High electric resistivity rocks associated with granites from the Sierra Bachoco basement might be the deep source of fluoride. Outcropping of Sierra Bachoco in the west causes upward regional flow. Groundwater of longer residence time can be pumped there. The anomalous area is restricted to “La Victoria” because calcareous paleozoic rocks outcrop to the south.  相似文献   

Problems of high fluoride waters in Turkey     

Xiaohong XIA Yong QIN 《中国地球化学学报》2006,25(B08):55-55

The geochemistry theory can provide information about the distribution, contents and migration in nature of the chemical elements in minerals, rocks, soils, waters, atmospheres, etc. Therefore, it has been applied extensively. Nowadays the petroleum supply throughout the world is in tension. The coal resources are unfriendly to the environment, because coals contain many harmful chemical elements. How to exploit the efficient clean liquid energy from coals is a hot subject of study. This paper deals with the present domestic and international applications of geochemistry in coal liquefaction research, on the basis of coal geology, points out the shortages and problems that need to be dissolved, clarifies the necessity of coal liquefaction technique research under the coal geochemistry background. To enhance the oil production and reduce environmental effects, the direct coal liquefaction technique research should take it into consideration the three-aspects coupling pattern, which includes the influence of coal direct liquefaction activity combined with different geochemical parameters, the different migration behaviors of harmful elements in the coal liquefaction process, and the geological control factors of coal-forming environments. It is indicated that the coal geochemistry is extensively applied in coal direct liquefaction technique research.  相似文献   

Removal of fluoride from aqueous solution by modified fly ash   总被引：1，自引：0，他引：1  

Li LUO Liang LU Guoqiang WU Jianjun CHEN 《中国地球化学学报》2006,25(B08):129-129

Removal of fluoride from aqueous solution by modified fly ash was studied in batch model. The influences of the contact time, the initial F^- concentration, the dosage of fly ash, and the temperature on removal of F have been studied, respectively. It was found that fly ash modified with dilute HCl has the maximum adsorption of fluoride from aqueous solutions, and that the retention of fluoride ions by material was 85% or higher with initial 10 mg F^-/L. First-order kinetics was observed for the adsorption process, which follows the Langrnuir and Freundlich isotherms. The thermodynamic parameters such as ΔG0, ΔH0, ΔS0 were calculated from Langmuir constants. The positive value of ΔH0 （1.273 J/mol） confirms the endothermic nature of adsorption.  相似文献   

改性蒙脱石吸附水中氟离子的实验研究   总被引：19，自引：0，他引：19  

范丽珍  廖立兵  田玉莲 《矿物学报》2001,21(1):34-38

制备四种改性蒙脱石，并利用X射线衍射分布和化学成分分析方法对其进行了表征，选用其中两种对水中的氟离子进行了吸附试验，通过正交实验确定了它们吸附氟离子的适宜条件及吸附等温线（25℃）。结果表明，制备的改性蒙脱石具有很强的吸附氟离子的能力，在pH分别为5和4时的除氟效果最好，吸附等温线符合Freundlich型吸附等温线方程。  相似文献   

Monitoring of the integrated column of hydrogen fluoride above the Jungfraujoch Station since 1977 — the HF/HCl column ratio     

R. Zander  G. Roland  L. Delbouille  A. Sauval  C. B. Farmer  R. H. Norton 《Journal of Atmospheric Chemistry》1987,5(4):385-394

The amount of hydrogen fluoride (HF) above the International Scientific Station of the Jungfraujoch (Switzerland) has been monitored during the last 8 years. The results deduced spectro-scopically from solar IR absorption measurements near 2.48 m indicate a cumulative trend equivalent to (8.5±1)% increase per year, as well as short-term variability which appears to be strongly correlated with meridional circulation patterns during the February–April months. Based on intensified measurements made over the last three years, it is found that the integrated content of HF undergoes a seasonal change with a minimum occurring in the fall. The HF/HCl ratio derived from simultaneous HF and HCl measurements was found equal to 0.15 during the period 1977–79, and 0.24 for the 1983–85 timespan.  相似文献   

X射线荧光光谱法测定高氟地质样品中氟、钙等元素     

袁建  夏晨光  刘高辉  刘香英 《铀矿地质》2016,(3):175-179

采用X射线荧光光谱法测定高氟地质样品中氟、钙等元素,对样品进行熔融制样前处理,理论α系数和经验系数法校正基体效应。应用此方法分析国家一级标准物质和代表性样品,所测元素的精密度(RSD)均小于5%(除含量较低元素);分析不参加回归的标准物质和人工配制的标准样品,测量结果与标准值基本一致。通过实验数据可知,该方法可以满足高氟硅酸盐样品、萤石、萤石型铀矿、磷矿石等样品的测定要求。  相似文献   

Some Aspects of Fluorite and Vaterite Precipitation in Marine Environments*     

Karl J. Wittmann  Antonio P. Ariani 《Marine Ecology》1996,17(1-3):213-219

Abstract. Mysid shrimps of the genus Schistornysis precipitate either fluorite (CaF₂; S. spiritus) or vaterite (CaCO3; S. assimilis) for the formation of static bodies (statoliths). In S. assirnilis, 2.44 μg calcium and 3.66 μg carbonate are precipitated for each statolith. This corresponds to 69 mg or 30 mg ambient water, respectively, using the ion content of seawater for stoichiometrical comparison. Concentmtion factors of calcium or carbonate in relation to equivalent amounts of ambient water in the statocyst cavity are 760 or 3100, respectively. In S. spiritus, 3.79 μg calcium and 3.60 μg fluoride are precipitated. This corresponds to 9.3 mg or 2788 mg ambient water, respectively. Concentration factors with respect to statocyst water mass are 610 or 183.000. respectively. Ile high fluoride accumulation for the formation of statoliths alone contributes to a fluoride content of 4500 ppm with respect to body dry weight A minimum estimate for the role of mysids in the global fluoride cycle suggests that at least 62,000 tons of fluoride are bound in mysid statoliths. Due to rapid turnover of about seven days, mysid fluorite statoliths are a crucial factor by contributing to a turnover of at most 570,000 years for overall fluoride in the oceanic system.  相似文献