Groundwater through hand-operated tubewell (a type of water well) tapping is the main source of drinking water in Bangladesh. this study investigated iron and manganese concentration in groundwater across Jashore district-one of the worst arsenic contaminated area in Bangladesh. one working tubewell that had been tested previously for arsenic and marked safe (green) was selected from each unions of the district. Results revealed that approximately 73% and 87% of groundwater samples exceeded the limits for iron and manganese in Bangladesh drinking water, respectively. Additionally, spatial distribution of iron and manganese indicate that only 5% of the total surface area of groundwater is covered by safe level of iron and manganese. Human health risk due to ingestion of iron and manganese through drinking water was evaluated using hazard quotients (HQ) for adults and children. the result of the health risk assessment revealed that the non-carcinogenic health risks due to ingestion of iron (HQ up to 1.446 for adults and 0.590 for children) and manganese (HQ up to 2.459 for adults and 1.004 for children) contaminated groundwater are much higher among adults than children. on the basis of occurrences, spatial distribution and health risk assessment results, the area can be categorized as a high-risk zone for iron and manganese-related problems and needs special attention in order to protect public health of local residents. Groundwater is the main source of drinking water in Bangladesh and over 90% of the country's drinking water source is groundwater. Now, it is estimated that close to 98% of the population of Bangladesh have access to 'technologically improved water source' but this level is likely lower than 39% when considering Sustainable Development Goal water target (SDG goal 6.1) 1 of 'safely managed water' 2. Safely managed water services ensure access to a technologically improved water source which is available when needed, located on premises and free of fecal and priority chemical contamination. In Bangladesh, access to technologically improve water source came mainly due to installation of tubewells-a type of water well, a low-cost technology used to withdraw groundwater by hand powered. Since their large scale installation in the 1970s and 1980s for obtaining microbiologically safe water, tubewells have become popular in Bangladesh, with close to 95% of rural people and 70% of urban people using them today 3. Even though groundwater can be a safe and reliable source of drinking water, it can also be affected by geogenic contaminants, such as arsenic, iron and manganese. Therefore, increased consumption of groundwater in some area has led to long-term exposures to arsenic 4 , iron 5 and manganese 6,7 that are associated with adverse health effects. Iron and manganese are naturally occurring metals, and coexist in groundwater as they have many common chemical properties including similar valence charge in physiological conditions, ionic radius and absorptive mechanisms for individuals 8,9. Iron and manga...

No abstract

No abstract

Removal of methylene blue (MB) dye from aqueous solution was studied using jute stick charcoal (JSC), prepared from jute (Corchorus olitorius) stick: an affordable and available agricultural by-product, as a low-cost adsorbent. All the experiments were carried out in batch mode. Controlling factors of the system, including contact time, solution pH, JSC dose and initial MB concentration, were investigated to study their effects on MB adsorption. JSC was characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscope. Adsorption equilibrium data fitted well with Freundlich and Halsey adsorption isotherms that describe the multilayer adsorption on heterogeneous surface. The maximum adsorption capacity calculated by the Langmuir isotherm was 29.32 mg/g. The MB adsorption process was well described by the pseudo-second-order kinetic model, and the MB diffusion in JSC was the potential rate-controlling step. Finally, JSC is a promising adsorbent for the adsorption of MB from aqueous solution.

No abstract