Pot experiments with soils from three contaminated sites and an additional field experiment were conducted. The aim of the experiments was to test different organic and inorganic soil amendments to heavy metal uptake and to alleviate toxicity in different agricultural crops. Elements in the extracts were measured by

In rural Bangladesh, drinking water supply mostly comes from shallow hand tubewells installed manually by the local drillers, the main driving force in tubewell installation. This study was aimed at developing a sediment color tool on the basis of local driller's perception of sediment color, arsenic (As) concentration of tubewell waters and respective color of aquifer sediments. Laboratory analysis of 521 groundwater samples collected from 144 wells during 2009 to 2011 indicate that As concentrations in groundwater were generally higher in the black colored sediments with an average of 239 μg/L. All 39 wells producing water from red sediments provide safe water following the Bangladesh drinking water standard for As (50 μg/L) where mean and median values were less than the WHO guideline value of 10 μg/L. Observations for off-white sediments were also quite similar. White sediments were rare and seemed to be less important for well installations at shallow depths. A total of 2240 sediment samples were collected at intervals of 1.5m down to depths of 100 m at 15 locations spread over a 410 km(2) area in Matlab, Bangladesh and compared with the Munsell Color Chart with the purpose of direct comparison of sediment color in a consistent manner. All samples were assigned with Munsell Color and Munsell Code, which eventually led to identify 60 color shade varieties which were narrowed to four colors (black, white, off-white and red) as perceived and used by the local drillers. During the process of color grouping, participatory approach was considered taking the opinions of local drillers, technicians, and geologists into account. This simplified sediment color tool can be used conveniently during shallow tubewell installation and thus shows the potential for educating local drillers to target safe aquifers on the basis of the color characteristics of the sediments.

Background: The origin of the spatial variability of dissolved As concentrations in shallow aquifers of the Bengal Basin remains poorly understood. To address this, we compare here transects of simultaneously-collected groundwater and aquifer solids perpendicular to the banks of the Hooghly River in Chakdaha, India, and the Old Brahmaputra River in Araihazar, Bangladesh.

The present work describes results of pot experiments and field studies including three contaminated sites in Bangladesh. The aim was to investigate possible differences between cereal varieties ith regard to heavy metal uptake and accumulation. A total of 10 rice (Oriza sativa L.) and 3 wheat (Triticum estivum) varieties were studied. Soil samples were digested with HCl:HNO 3 (3:1), and plant

Abstract:The present study was conducted to investigate effects of stocking density on growth performances of gold fish (Carassius auratus) in hapas. Experiment was conducted for a month with three treatments where three stocking densities were T 1 (10 fry/hapa), T 2 (15 fry/hapa) andT 3 (20 fry/hapa) each having three replications which were selected randomly. In the present experiment hapa (3ft × 2ft × 2ft) with 1 mm mesh net was used. Gold fish fry having a mean body weight of 0.007 g were used in all treatments. Fishes were fed at the rate of 10% of their body weight containing 34.11% protein. Water quality parameters were monitored at 10 days interval and the ranges were -temperature 24.75 to 27.75 o C, dissolved oxygen 3.68 to 4.09 mg/L, p H 7.3 to 8.16, ammonia 0.3 to 1 mg/L, nitrite 0.01 to 0.03 mg/L, phosphate 0.6 to 1 mg/L and alkalinity 119 to 187 mg/L. At the growth performances were evaluated by comparing mean final body weight, specific growth rate and food conversion ratio. The present study showed that the gold fish fry in T 1 resulted the best mean final weight gain (1.188 g) followed by T 2 (0.834 g) and T 3 (0.686 g). The SGR ranged between 6.64 and 7.43% per day and FCR ranged between 3.56 and 4.12 with T 1 showing the lowest FCR. The survival rate (%) ranged between 76.67% to 85.67%. From the present experiment it was found that individual fish growth rate was decreased with the increase of stocking density.

Exploitation of groundwater from shallow, high prolific Holocene sedimentary aquifers has been a main element for achieving safe drinking water and food security in Bangladesh. However, the presence of elevated levels of geogenic arsenic (As) in these aquifers has undermined this success. Except for targeting safe aquifers through installations of tubewells to greater depth, no mitigation option has been successfully implemented on a larger scale. The objective of this study has been to characterise the hydrostratigraphy, groundwater flow patterns, the hydraulic properties to assess the sustainability of the low-arsenic aquifers at Matlab, in south-eastern Bangladesh, one of the worst arsenic-affected areas of Bangladesh. Combining groundwater modelling with monitoring hydraulic heads in multi-level piezometer tests, 14 C-dating of groundwater, conventional hydraulic testing and assessment of groundwater abstraction rate proved to be a useful strategy. A model comprising of three aquifers covering the top 250 m of the model domain showed to best fit the evaluation criteria for calibration. Matlab is a recharge area, even though it is adjacent to the great Meghna River. Irrigation wells are placed in clusters and account for most of the groundwater abstraction. Even though the hydraulic heads are affected locally by seasonal pumping, the aquifer system is fully recharged during and after the monsoon period. Groundwater simulations demonstrated the presence of deep regional and horizontal flow systems with recharge areas in the eastern, hilly part of Bangladesh and shallow small local flow systems driven by local topography. Based on modelling and 14 C groundwater data, it can be concluded that the natural local flow systems reach a depth of 30 m b.g.l. in the study area. A downward vertical gradient of roughly 0.01 down to 200 m b.g.l. was observed and reproduced by calibrated models. The vertical gradient is mainly the result of the aquifer system and -properties rather than abstraction rate, which is too limited at depth to make an imprint. Although irrigation wells substantially change local flow pattern, targeting low-As aquifers seems to be a suitable mitigation option for providing people with safe drinking water. However, installing new irrigation-or high capacity production wells at the same depth is strongly discouraged as these substantially change the groundwater flow pattern. The results from the present study and other similar studies can further contribute to develop a rational management and mitigation policy for the future use of the groundwater resources for drinking water supplies.

Poly(propylene) (PP) matrix jute fiber reinforced composites were prepared by compression molding. Tensile strength (TS), tensile modulus (TM), percentage elongation at break (Eb%), bending strength (BS), bending modulus (BM), impact strength (IS) and hardness of the prepared composites (50% fiber by weight) were found to be 45 MPa, 2305 MPa, 12%, 52 MPa, 4267 MPa, 18 kJ/m2 and 95 shore-A, respectively. Non-vulcanized natural rubber (NR) was blended (10—50% by weight) with PP using extruder, and films (PP + NR) were prepared by heat press for composite fabrication. Jute fiber reinforced blended PP + NR based composites (50% fiber by weight) were fabricated and characterized. It was found that TS, TM, BS, BM and hardness of the composites were decreased with the increase of NR in PP but IS and Eb% were improved significantly.

In Bangladesh, among the routes of chromium eco-toxicity, feeds and fertilizer production from tanned skin-cut wastes is the most direct one leading to food chain contamination. The tanning industries of Hazaribagh are processing some 220 metric tons of hide a day with an associated release of 600 -1000Kg of tanned skin-cut waste (SCW) resulting from per ton processed hide. The SCW are protein-rich and are unscientifically used to produce protein-concentrates for poultry and fish feeds, and organic fertilizer. In view of the facts, a huge migration of chromium can happen into poultry products, fish and vegetables, and further bio-magnify into food chain. The target population of this phenomenon is also huge. Regional bio-concentration of chromium was investigated in commercially produced chicken eggs. Though the routes of distribution of this hugely produced protein-concentrates from SCW are unknown, eggs were sampled from Dhaka and its nearby other seven districts covering the central region of Bangladesh. Twelve eggs were randomly sampled from each district's egg stock market while albumen and yolk in each egg were studied separately for all studies. Out of the 192 samples from 96 eggs, dry weight basis mean chromium concentration was found to be 1.9016 ppm with a sample standard deviation of 0.1502. The concentration levels were ranged from maximum of 19.8051 ppm to undetectable levels. Single poultry egg was found to contain a mean chromium content of 23.3809 µg, which exceeds adequate daily dietary intake of children up to 8 years of age as well as corresponds to major part for other age groups. The region-wise physical properties of the eggs were also studied which included USDA size grading by whole weight at raw condition, whole weight ratio of raw condition to complete boiled condition, weight ratio of boiled shell-albumen-yolk, moisture content of albumen of boiled eggs, and moisture content of yolk of boiled eggs. The mean whole weights of eggs at raw condition were within the range of 39.9568 g ('peewee' as per USDA size grading) to 62.4047 g ('large' as per USDA size grading), the mean whole weight ratio of raw condition to complete boiled