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.