ASSESSMENT OF PHYSICO-CHEMICAL PROPERTIES OF SURFACE WATER OF SHITALAKHYA RIVER NEAR POLASH, NARSINGDI, BANGLADESH.

This study was carried out to examine the physico-chemical properties of the surface water of Shitalakhya River. Total thirty samples were collected from Polash-Ghorashal area in Narsingdi, Bangladesh and were analyzed for physico-chemical properties such as Temperature, pH, EC, Total Alkalinity, P-Alkalinity, DO, BOD5, COD, NH3-N, NO3-N & SiO2 to monitor the level of water quality of the River. Obtained results of the present study shows that most of the parameters exceed the maximum permissible limit in pre-monsoon and dry season. Ammonia was found to be the major pollutant of the River. Overall of the seasons NH3-N and BOD5 exceeded the allowable limit for aquatic life and the highest concentration of NH3-N (342.99 mg/L) was recorded along the River in pre-monsoon near at the point source of UFFL. Among the thirty samples, seventeen samples showed P-alkalinity probably due to hydroxide alkalinity. In pre-monsoon the DO value (2.59-3.82 mg/L) was found to be stressful for aquatic life though the value changes in winter season when it became highest (6.6-5.86 mg/L). From the statistical point of view temperature, pH, alkalinity, EC, COD, BOD5, Ammonia-N, NO3-N and SiO2 are positively correlated to each other while with DO, most of the parameters are negatively correlated. The results reflect the poor effluent quality generated by Urea Fertilizer Factory (UFF) and indicates that the water of Shitalakhya River is not safe for drinking purposes, fisheries, recreational activities and various industrial uses particularly in Winter, Dry and Pre-monsoon seasons of the year.