Assessment of Water Quality of Bhabadah Water-logging Area of Khulna Division

Abstract

Surface water is one of the most important natural resources for irrigation and drinking purposes which has direct and indirect influence on human, livestock, aquatic organisms, soils, crop and agroecosystem. An attempt was made to assess the quality of surface water collected from three Upazilas of Bhabadah water-logging area of Khulna Division, Bangladesh for irrigation and drinking usage. Total 40 surface water samples were collected from the study area. All the chemical analyses of water quality were done following standard methods. The pH value of the water samples was within admissible range which was not problematic for irrigation and drinking usage. Electrical conductivity (EC) values were within the range of 461.0 to 2910.0 µS cm-1 . As regards to Sodium Adsorption Ratio (SAR), all the surface water samples were excellent class for irrigation usage. Based on Soluble Sodium Percentage (SSP), 35 samples were classified as excellent (SSP<20%), four samples were rated as good (SSP= 20-40%), one sample was rated as permissible class (SSP=41-60%) and no sample was classified as doubtful (SSP = 61-80%). According to RSC and permeability index (PI), all the water samples were suitable for irrigation use. Salinity and alkalinity hazard index based on SAR and EC indicated that, one sample was under low salinity class (C1), six samples under medium salinity class (C2), 33 samples under high salinity class (C3) and all the water samples were low alkalinity (S1) hazards. As per hardness (HT), all samples are soft in nature. The ionic dominance was in the order of Cl- > Ca2+ > Mg2+ > SO4 2- > Na+ > PO4 3- > HCO3 - > K+ . Contaminants present in surface water samples might be ignored and after some chemical treatment, it could be used for irrigation and drinking purpose.