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1.
Munawar Sultana Taslin Jahan Mou Santonu Kumar Sanyal Farzana Diba Zahid Hayat Mahmud Anowar Khasru Parvez M. Anwar Hossain 《Ground water》2017,55(5):736-746
Arsenotrophic bacteria contribute to the nutrient cycling in arsenic (As) affected groundwater. This study employed a culture‐independent and ‐dependent investigation of arsenotrophic microbiomes in As affected groundwater samples collected from Madhabpur, Sonatengra, and Union Porishod in Singair Upazila, Manikganj, Bangladesh. Total As contents, detected by Atomic Absorption Spectrophotometry (AAS) of the samples, were 47 µg/L (Madhabpur, SNGW‐1), 53 µg/L (Sonatengra, SNGW‐2), and 12 µg/L (Union porishod, SNGW‐3), whereas the control well (SNGW‐4; depths >150 m) showed As content of 6 µg/L. Denaturing Gradient Gel Electrophoresis (DGGE) analysis of the amplified 16S rRNA gene from As‐affected groundwater samples revealed the dominance of aerobic bacteria Pseudomonas within heterogeneous bacterial populations. DGGE of heterotrophic enrichments supplemented with arsenite [As (III)] for 4 weeks showed the dominance of Chryseobacterium, Flavobacterium, and Aquabacterium, whereas the dominant genera in that of autotrophic enrichments were Aeromonas, Acinetobacter, and Pseudomonas. Cultured bacteria retrieved from both autotrophic and heterotrophic enrichments were distinguished into nine genotypes belonging to Chryseobacterium, Acinetobacter, Escherichia, Pseudomonas, Stenotrophomonas, Janibacter, Staphylococcus, and Bacillus. They exhibited varying range of As(III) tolerance from 4 to 27 mM. As(III) transformation potential was confirmed within the isolates with oxidation rate as high as 0.143 mM/h for Pseudomonas sp. Sn 28. The arsenotrophic microbiome specifies their potential role in groundwater As‐cycling and their genetic information provide the scientific basis for As‐bioremediation. 相似文献
2.
Q. H. Mazumder C. S. Jahan F. Mazumder M. A. Islam S. Jaman M. N. Ali A. T. M. S. Rahaman M. R. Arefin A. Ahasan 《Journal of the Geological Society of India》2014,84(4):431-441
In the salinity affected lower Atrai floodplain aquifer in the NW Bangladesh, geoelectric resistivity survey and hydrochemical analysis are carried out with an aim to identify fresh and saline groundwater zones; investigate the status of salinity; evaluate hydrochemical processes involved and suggest management approaches for irrigation. Here a two-fold aquifer system, inter-layered by silt, clay and silty-clay aquitard and aquiclude is classified as: upper aquifer — spatially affected by salinity of varying degrees; and lower aquifer — generally characterized by high salinity. The aquifer with resistivity values greater than 69 Ωm is safe for irrigation use. Concentrations of major ions vary as: Ca2+>Na+>Mg2+>K+ and HCO3>Cl>NO3>SO4 2?. Groundwater is dominated by Na-Ca to Ca-Na, HCO3-Cl-SO4, Cl-SO4-HCO3 and Cl-SO4 2? facies where Ca2+, Mg2+, SO4 2?, HCO3 ?, Cl? and NO3 2? ion concentrations are statistically dominant and water is of Ca-Mg, HCO3-SO4-Cl and NO3 types. Geochemically, groundwater is hard and saline to fresh water type. Salinity increases with depth, but spatially towards the southern part. Groundwater quality is a product of water-rock interaction, direct mixing and marine spraying, or fall-out of airborne marine salts, where silicate weathering is the primary source of bivalent cations. Sediment provenance of alkaline earth silicates and higher concentrations of alkalis are derived from sources other than precipitation. In general partially or fully salinity affected upper and lower aquifers in the area except in its eastern part are not suitable for tubewell irrigation. As groundwater demand for irrigation is increasing, the saline water has progressively invaded relatively fresher parts of the aquifer by upconning. So, special salinity control management approaches can be adopted through engineering techniques such as groundwater abstraction optimization, as also through scientific behavioral approaches like groundwater demand management, salt tolerant crops production. In this context, surface water conservation and rain water harvesting for domestic and irrigational uses are recommended in the salinity affected area. 相似文献
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K. K. Agarwal Nigar Jahan Amar Agarwal 《Journal of the Geological Society of India》2010,75(2):411-414
The folds generally initiate at several discrete points along a layer or multilayer undergoing compressional forces. These
compressional forces often lead to rotation of fold segments and in all such regimes, folds are strongly asymmetrical and
are in complete agreement with the direction in which the force is applied and also with the related thrust sheet movement.
This paper illustrates the progressive change in fold geometry with increasing compression and ductile shearing using natural
example as studied in the Almora Crystalline Zone (ACZ). 相似文献
5.
利用新疆南疆各地州1949~2008年间发生的大风天气所造成的死亡人口、受灾农田面积、经济损失和死亡牲畜资料,评估南疆风灾的灾度及其时空变化特征进行深入分析。分析得出:(1)阿克苏、喀什和巴州重大风灾天气发生次数多,强度大,是风灾防范和灾后救助的重点地区;和田和克州重大风灾天气发生次数少,强度弱,是风灾防范和灾后救助的次重点地区;在4~5月份重大风灾天气发生次数多,持续时间长,而且4~5月份是作物播种和出苗期,大风容易成灾,为此4~5月份是风灾防范和灾后救助的重点季节。(2)重大风灾天气发生次数由20世纪50年代至90年代逐年增长,自21世纪开始略有减少;重大风灾天气在巴州发生次数最多,在60a间为84次,其次喀什75次,阿克苏67次,和田和克州较少。(3)风灾经济损失随着工农业生产总值的增长而增加,而且增长速度比经济增长速度快,建议增加防治风灾投入,改善生态环境,加快退耕还林还草进程,建立减灾系统,加强风灾防治。 相似文献
6.
Chowdhury Sarwar Jahan Md. Ferozur Rahaman Riad Arefin Shamser Ali Quamrul Hasan Mazumder 《Journal of the Geological Society of India》2018,91(5):613-620
Demand for irrigation water increases day by day along with meteorological vagaries and extension of irrigated area in the drought-prone Barind area of Bangladesh. This increasing stress on water resource is gradually making the area water scare. The study is aimed at studying the morphometric parameters of the Atrai-Sib river basin in the Barind area and on their relevance in water resource management based on satellite images and SRTM DEM. Computation and delineation of linear and areal aspects of the river basin and its morphometric components reveals that stream order ranges from first to eighth order showing dendritic drainage pattern. The basin represents homogeneity of soil texture; possibility of flash flood after heavy rainfall with low discharge of runoff; and is not largely affected by structural disturbance. Moderate drainage density of the river basin area indicates semipermeable soil lithology with moderate vegetation. Mean bifurcation ratio of the basin is calculated as 3.92 and elongation ratio 0.75, which indicate elongated shape of the river basin with low to moderate relief bounded in the east and west by ‘moderate to steep’ sloping land area. It reveals a flatter peak of runoff flow for longer duration and gravity flow of water. The gentle but undulating slope of the basin represents ‘excellent’ category for groundwater management as the site is favorable for infiltration due to maximum time of runoff water percolation. The east facing slopes of the basin show higher moisture content and higher vegetation than the west-facing slope. The land use pattern of the area shows that major part (95.29%) comes under the cultivated land which will support future river basin development and management. Results obtained from the study would be useful in categorization of river basins for future water resource development and management, and selection of suitable sites for water conservation structures such as check dam, percolation tank, artificial recharge of groundwater through MAR technique etc. 相似文献
7.
M. Al Mamunul Haque C. S. Jahan Q. H. Mazumder S. M. S. Nawaz G. C. Mirdha P. Mamud M. I. Adham 《Journal of the Geological Society of India》2012,79(1):77-84
The Rajshahi city is the fourth largest metropolitan city in Bangladesh on the bank of the River Padma (Ganges). Here an upper
semi-impervious layer overlies aquifer — the source for large-scale groundwater development. The groundwater resource study
using Visual MODFLOW modeling shows that recharge occurs mainly due to infiltration of rainfall and urban return flow at low
rate, and water level fluctuates seasonally in response to recharge and discharge. Hydraulic connection between river and
aquifer which indicates inflow from high river water levels beyond its boundaries. The total groundwater abstraction in 2004
(15000 million liters) is lower than total input to aquifer reveals an ample potentiality for groundwater development with
increasing demand. But groundwater shortage (1000 million liter/year) especially in the vicinity of the River Padma in dry
season happens due to its increasing use and fall of river water level resulting in reduced inflows and hence decline in groundwater
level. The conjunctive use of surface water-groundwater and its economic use will help for sustainable groundwater supply
to avoid adverse impact. 相似文献
8.
Barbara?BarlettaEmail authorView authors OrcID profile Isobel?J.?Simpson Nicola?J.?Blake Simone?Meinardi Louisa?K.?Emmons Omar?S.?Aburizaiza Azhar?Siddique Jahan?Zeb Liya?E.?Yu Haider?A.?Khwaja Muhammad?A.?Farrukh Donald?R.?Blake 《Journal of Atmospheric Chemistry》2017,74(1):87-113
We investigate the composition of 63 C2-C10 nonmethane hydrocarbons (NMHCs), methane (CH4) and carbon monoxide (CO), in Jeddah, Mecca, and Madina (Saudi Arabia), in Lahore, (Pakistan), and in Singapore. We established a database with which to compare and contrast NMHCs in regions where ambient levels and emissions are poorly characterized, but where conditions are favorable to the formation of tropospheric ozone, and where measurements are essential for improving emission inventories and modeling. This dataset will also serve as a base for further analysis of air pollution in Western Saudi Arabia including, but not limited to, the estimation of urban emissions and long range pollution transport from these regions. The measured species showed enhanced levels in all Saudi Arabian cities compared to the local background but were generally much lower than in Lahore. In Madina, vehicle exhaust was the dominant NMHC source, as indicated by enhanced levels of combustion products and by the good correlation between NMHCs and CO, while in Jeddah and Mecca a combination of sources needs to be considered. Very high NMHC levels were measured in Lahore, and elevated levels of CH4 in Lahore were attributed to natural gas. When we compared our results with 2010 emissions from the MACCity global inventory, we found discrepancies in the relative contribution of NMHCs between the measurements and the inventory. In all cities, alkenes (especially ethene and propene) dominated the hydroxyl radical (OH) reactivity (k OH) because of their great abundance and their relatively fast reaction rates with OH. 相似文献
9.
M. I. Adham C. S. Jahan Q. H. Mazumder M. M. A. Hossain Al-Mamunul Haque 《Journal of the Geological Society of India》2010,75(2):432-438
The groundwater recharge potentiality in Barind Tract in Rajshahi district, Northwest Bangladesh was studied based on Geographical
Information System (GIS) and Remote Sensing technique. In this connection satellite images (Landsat 7 ETM and SPOT) and aerial
photos were subjected to several treatment processes using softwares like ERDAS Imagine and ESRI’s Arc View. Thus various
thematic maps have been prepared for drainage density, lineaments, lithology and land cover/use that allowed deciding their
interactive effect. In the present study, the degree of effect was determined for each factor to assess the total groundwater
recharge potentiality for two categories (moderate to low). The resultant map shows that 85% of the area has low, and rest
has moderate groundwater recharge potentiality. Finally only 8.6% of the total average annual precipitated water (1685mm)
percolates into subsurface and ultimately contributes to recharge the groundwater. 相似文献
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