Water and sediment samples have been collected from five different stations, located along Djendjen River between February and June, 2016 so that the concentrations of Cd, Ni, Zn, and Cu could be determined. The extent of the sediment pollution has been assessed, using the multiple pollution indices, namely Contamination Factor (CF), Pollution Load Index (PLI), and the geoaccumulation index (Igeo).The distribution of trace elements in water and sediment follows Ni>Zn>Cd>Cu and Zn>Ni>Cu>Cd, respectively. The water sample analysis from Djendjen River shows that the total concentrations of Cu, Ni, Cd, and Zn have been lower according to the references. In comparison, sediment mean metal concentrations with several environmental contamination parameters, like probable effect level (PEC) and background levels, indicates that the concentrations of all investigated elements are lesser than PEC, except for Ni, but higher than the background levels. The Igeo values reveal that Cd has been the most accumulated compared to the other metals.  Contamination Factor (CF) confirms that the sediment samples have been moderate in terms of all studied metals contamination. The Pollution Load Index (PLI) values have been above one (>1), indicating an advanced decline of the sediment quality.

Water is one of the most crucial substances for life. In order to maintain their public health, each and every country has defined standards of drinking water quality, beyond which the water is considered harmful for human health. The current study compares physical, chemical, and biological standards of drinking water quality for the USA, EU, Japan, India, and Bangladesh, considering 4 physical parameters (namely, color, odor, taste, and turbidity), 35 chemical parameters (such as Calcium (Ca), Magnesium (Mg), Phosphate (PO43-), Sodium (Na), Phenolic compounds, Nitrite (NO2-), Arsenic (As), Aluminum (Al), etc.) and 2 biological parameters (i.e., Coliform (Fecal) and Coliform (Total)). The data has been collected from several secondary sources and since processes of data collection for water quality differ from one another, this aspect has been ignored. No variation has been found in biological water quality standards along with physical quality standards of the considered regions. In order to find out the differences in chemical parameters, standard ANOVA and pair-wise F-test have been conducted. There was no disparity among chemical parameters in ANOVA test. Moreover, thanks to the few excessive values of the standards (as in case of Bangladesh), the COD value is 4 mg/L, whereas in other countries this parameter is much less. However, the chemical parameters of water quality standards in Bangladesh vary significantly from other countries. Besides, there has been no variation among the standards of other countries, even though they are located in different continents. Most interestingly, despite being neighbors, Bangladesh and India differ significantly in this regard.