Study Area: Pabna Sadar is an upazila of Pabna district in the division of Rajshahi, Bangladesh . It is located at latitude24.00oN and longitude 89.25oE, has a tropical environment. It has an area of 443.90 sq km, which is bounded by Atgharia and Iishwardi upazilas on the north, Kushtia sadar, Kumarkhali, Khoksa and Pangsha upazilas on the south, Santhia and Sujanagar upazilas on the east, Ishwardi upazila on the west. Main rivers are Ganges and Ichamati and noted depressions are Sonapatil Beel and Tara pasha Canal.
Sample collection: In this study, the sampling sites are located inside Pabna Sadar Upazila. Twenty (20) samples were collected from the study area. Among them ten (10) surface water samples were collected in plastic bottles from ponds, lakes and rivers and 10(ten) soil samples(0- 15 cm) were collected randomly in the vicinity of the surface-water sampling sites. Samples were collected by proper sampling procedure in rainy season (May, 2007) and analysis of the samples was performed around two months by using standard analytical methods.
Sample Analysis: The physicochemical parameters, anion concentrations and heavy metal concentrations of surface water (lakes, pondsand rivers) samples were analyzed by different standard methods in the laboratory of analytical research division, BCSIR laboratories, Dhaka. Physicochemical parameters such as pH, total suspended solid (TSS), total dissolved solid (TDS), electrical conductivity (EC), turbidity, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD) of the surface water samples were measured using various standard methods (APHA, 1976). A quantitative analysis of floride (F-), Chloride (Cl-), Bromide (Br-), Nitrate (NO3 -), Nitrite (NO2 -), and Sulfate (SO4 2-) of the surface water samples were determined by Ion Chromatography (1C). A quantitative analysis of Ammonia (NH3) and Phosphorus (P) of the surface water were determined by UV Spectrophotometer (Model- Lambda 25, Perkin Elmer) at 400nm wave length. Phosphate (PO4 3-) concentration of the surface water samples was determined from phosphorus (P) concentration using the factor (95/31=3.0645)( Sultana et al., 2009) . Pb, Zn, Cd and Cu - concentrations of the surface water were determined by Anodic Striping Voltammetry (AVS) and Cr, Mn, Fe, Co, Ni,As and Hg were determined by Atomic Absorption Spectroscopy (AAS). The soil samples were air dried, sieved (1mm) and after oven dried at 80°C, ground to powder. After acid digestion, the residue was dissolved in dilute acid solution to yield the sample solutions. Further a quantitative analysis of heavy metals such as Chromium (Cr), Manganese (Mn), Iron (Fe), Cobalt (Co), Nickel (Ni), Arsenic (As), Zinc (Zn), Cadmium (Cd), Mercury (Hg) and Lead (Pb) of the soil were determined by Atomic Absorption Flame Emission Spectrophotometer (AAS) Model: SHIMADZU, AA-6401F.