J. Agrofor. Environ. 5 (2): 21-26, 2011 ISSN 1995-6983 Quality assessment of waters of Bogra city area, Bangladesh H.M. Zakir, Kohinoor Begum, K.M. Mohiuddin and M.Y. Arafat Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh- 2202, Bangladesh Abstract: A study was conducted at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh-2202 to determine major ionic constituents including heavy metals in waters collected from fourteen different locations of Bogra city, and accordingly to assess their quality. The concentration of heavy metals in water samples were determined by using an atomic absorption spectrophotometer (AAS). The electrical conductivity (EC) values of water samples varied from 326 to 1265 μS cm -1 while the pH range was 6.26 to 7.25. In respect of total dissolved solids (TDS), all water samples were categorized as fresh water. Dissolved oxygen (DO) values of samples in the study area were within the range of 0.3 to 0.6 mg L -1 , indicating severe stress for aquatic biota. The mean concentrations of Ca 2+ , Mg 2+ , Na + , K + , BO 3 3- , PO 4 3- and SO 4 2- in water samples were 51.67, 26.07, 32.77, 11.98, 0.25, 0.67 and 10.85 μg mL -1 , respectively. Considering Cl - content, 50% water samples were found within the permissible limit of irrigation, but in respect of HCO 3 - content, all water samples were problematic for irrigation. According to drinking water quality guideline, all water samples of the study area were found unsuitable in respect of HCO 3 - and Cl - contents. The mean concentrations of total Fe, Mn, Cr and Ni in water samples were 0.79, 0.25, 0.005 and 0.012 μg mL -1 , respectively while the amount of Zn, Cu and Pb were below the detectable limit. The quality assessment showed relatively high values of Fe and Mn in most of the water samples, which would make them unsafe for drinking and irrigation purpose, respectively. Key words: Water quality, heavy metal, Bogra, Bangladesh. Introduction The overall global environment is being polluted fast and the causes are connected with various factors. Industrialization, waste disposal systems, lack of logistic support and monitoring, and unplanned urbanization have greatly transformed the natural environment. In recent times, the environment has become hostile, posing threat to health and welfare due to release of pollutants from industries and urban sewage (Ntengwe, 2006). In Bangladesh, there is a progressive increase in industrial wastes and due to the rapid industrialization such waste products have been causing severe contamination to the air, water and soils, thus polluting the environment. Heavy metals that have been identified in the polluted environment include As, Fe, Mn, Cu, Cd, Pb, Cr, Ni, Hg, Zn etc. These heavy metals enter into the environment through various industrial processes. Water resource, the prominent component of the environment is getting polluted over the years. Wastewater is mainly used for irrigation purpose, because this contains nutrients that enhance the growth of crop plants but it is also known to have significant contribution to the heavy metal content of soils. About 80% of the diseases in developing countries are related to contaminated water and the resulting death toll is as much as 10 million per year (Anonymous, 2004). Heavy metal can cause surface and ground water contamination and are taken up by plants, released as gases into atmosphere or bound semi permanently by soil components such as organic matter and clay particles which later affect human health (Krishna and Govil, 2007). The presence of any metal may vary from site to site, depending upon the source of individual pollutant. Excessive uptake of metals by plants may produce toxicity in human nutrition, and cause acute and chronic diseases. For instance, Cd and Zn can lead to acute gastrointestinal and respiratory damages and acute heart, brain and kidney damages. Heavy metal pollution in the environment is quite relevant in the present scenario due to its deleterious effect on human health via food chain. Biosphere pollution by heavy metals has accelerated dramatically during the last few decades as a result of discharge of wastewaters from various industries and urban population. Therefore, the present research work was carried out to determine the concentration of major ionic constituents including heavy metals in waters collected from different areas of Bogra city, Bangladesh with a view to assess the level of contamination by using worldwide standards. Materials and Methods Bogra district has an area of 2919.9 sq. km. with annual average temperature maximum 34.6°C and minimum 11.9°C, and annual rainfall 1610 mm. Bogra is one among the newly industrial based areas of Bangladesh, which is highly susceptible to environmental pollution due to over population, rapid industrialization and urbanization in last 10 years. There are several types of industrial units including aluminium and ceramic factories, pharmaceutical and cosmetics industries, diesel plants, packaging industries, brick fields, garments and many others. Fourteen water samples were collected from some selected areas of Bogra city, Bangladesh (Table 1) following a standard procedure as outline by APHA (2005). Sampling was done during the month of October and November, 2010. About 500 mL water sample was collected from each location in plastic bottle and filtered through Whatman No.1 filter paper to remove unwanted solid and suspended materials. Then 3-4 drops of nitric acid were added to the samples to avoid any microbial growth. The pH, EC, TDS and DO values of water samples were measured by pH meter (Model-WTW pH 522), EC meter (Model-D.6072 Dreieich, West Germany), TDS meter (Model-HACH sensION TM + EC5, USA) and DO meter (Model-OXi 3150i, Germany), respectively. Carbonate, bicarbonate and chloride concentrations in water samples were determined by titrimetric method following the procedure as mentioned by Tandon (1995). Amount of phosphate and sulphate in water samples were measured spectrophotometrically following the procedure outlined by Tandon (1995) and Wolf (1982). Concentrations of calcium and magnesium were determined from water samples by titrimetric method using Na 2 EDTA as a chelating agent (Page et al., 1982 and Singh et al., 1999).