Browsing by Author "Das, S."

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A STUDY ON GROUND WATER LEVEL FLUCTUATION IN SELECTED AREA O F CHITTAGONG CITY
(Dept. of CE, CUET, 19-Dec-2018) Akter, S.; Hossen, M. A.; Das, S.
Southern part of Bangladesh is now facing water scarcity problems in both agriculture and secured livelihood. Ground water forms the major portion of earth’s fresh water source and it is almost safe to drink. Depletion of ground water table due to continuous pumping is causing scarcity of water in the city area of Bangladesh. So, information about ground water table is required for future recommendation of ground water supply to general people. For the investigation purpose, depth of water table has been determined in one season with respect to mean sea level. 41 wards of Chittagong City Corporation along north-south direction of 91˚47´ longitude and east-west direction of 22˚20´ latitude have been selected for this purpose where depth of water table has been measured from the shallow and deep tube well. The present investigation includes field investigation with the aim of measuring water level from ground surface. From this investigation, it has been established that, water table with respect to mean sea level is different at different wards. During field investigation, 82 shallow tube wells and 82 deep tube wells in 41 wards were found. The overall view shows that, in almost every ward, deep tube well is must to find fresh water as shallow tube well can’t frequently pump water. From the investigation, it is also clear that ground water table is lowering day by day. At the beginning of rainy season when it started to rain the water table comes up. Ground water through shallow tube well is not sufficient to fulfill the required demand for the general people as it is becoming out of reach through shallow well day by day. Depth of water table with respect to mean sea level is quite lower in ward 37& depth of water table with respect to mean sea level is quite higher in ward 13. The study was also carried out to assess groundwater table of Chittagong city. From this analysis, it is found that the GW level is lowering in almost all the region of the study. So, alternative water source should be ensured to mitigate the problem.
Label Free Flexible Electrochemical DNA Biosensor for Selective Detection of Shigella flexneri in Real Food Samples
(Elsevier, 2023-02-01) Ali, M.R.; Bacchu, M.S.; Das, S.; S. Akter; Rahman, M.M.; Aly, M.Aly Saad; Khan, M.Z.H.
An effective tool for early-stage selective detection of the foodborne bacterial pathogen Shigella flexneri (S. flexneri) is essential for diagnosing infectious diseases and controlling outbreaks. Here, a label-free electrochemical DNA biosensor for monitoring S. flexneri is developed. To fabricate the biosensor, detection probe (capture probe) is immobilized on the surface of poly melamine (P-Mel) and poly glutamic acid (PGA), and disuccinimidyl suberate (DSS) functionalized flexible indium tin oxide (ITO) electrode. Anthraquinone-2-sulfonic acid monohydrate sodium salt (AQMS) is used as a signal indicator for the detection of S. flexneri. The proposed DNA biosensor exhibits a wide dynamic range with concentration of the targets ranging from 1 × 10−6 to 1 × 10−21 molL−1 with a limit of detection (LOD) of 7.4 × 10−22 molL−1 in the complementary linear target of S. flexneri, and a detection range of 8 × 1010–80 cells/ml with a LOD of 10 cells/ml in real S. flexneri sample. The proposed flexible biosensor provides high specificity for the detection of S. flexneri compared to other target signals such as discrete base mismatches and different bacterial species. The developed biosensor displayed excellent recoveries in detecting S. flexneri in spiked food samples. Therefore, the proposed biosensor can serve as a model methodology for the detection of other pathogens in a broad span of industries.
The presence of carcinogenic radon in the Padma River water, adjacent to the Rooppur Nuclear Power Plant
(Daffodil International University, 2023) Siraz, M.M. Mahfuz; Alam, M.S.; A.M., Jubair; Das, , S.C.; Ferdous, J.; Hossain, Z.; Das, S.; Khandaker, Mayeen Uddin; Bradley, D.A.; Tokonami, Shinji; Yeasmin, S.
Radon is a naturally occurring carcinogenic agent, poses a serious health hazard when inhaled or ingested in significant amounts. The water of the Padma river will be used as a tertiary coolant for the soon-to-be-commissioned ‘Rooppur Nuclear Power Plant’. Hence, it is important to assess the radiological status of the river prior to the commission of this power plant. Therefore, for the first time, 25 samples of water were collected from various locations of the Padma River and analyzed for radon concentration using the RAD H2O (DURRIDGE) radon monitoring device. The radon concentrations were found in the range from 0.077 ± 0.036 to 0.494 ± 0.211 Bq/L with a mean of 0.250 ± 0.093 Bq/L. All the concentrations were found to be below the recommended limits of WHO (100 Bq/L) and USEPA (11.1 Bq/L). The mean annual effective dose due to the radon exposure via inhalation and ingestion pathways were 0.638 μSv/y and 0.629 μSv/y, respectively, which were all well below the annual effective dose recommended by WHO (0.1 mSv/y). Since Bangladesh lacks a national safety limit of radon in water, this pioneering study provides baseline data on radon levels for the environment around Rooppur Nuclear Power Plant.