ASSESSMENT OF IONIC TOXICITY OF BURIGANGA RIVER WATER AND ITS SUITABILITY FOR IRRIGATION, DRINKING, LIVESTOCK AND INDUSTRIAL USES

Abstract

The study was conducted to assess the degree of ionic lox icily and classify the water on the basis of standard criteria for irrigation. drinking, livestock, poultry, aquaculture and industrial purposes of 33 water samples of the River Buriganga nearby Dhaka city. Out of 33 water samples 27 from Buriganga River (1) oF dry season and 16 of rainy season) and 6 from deep tubewells (different spots of Dhaka city) were collected from different nonpoint (in case of river) and point sources in order to study the dissolved chemical constituents. The chemical analysis included p1-I, electrical conductivity (EC). total dissolved solids (TDS) and major ionic constituents like Ca2 Mg2 . K'. Na'. Fe3t, Mn2. B3 . A53'. Cut. pot. Cot2'. HCO3'. SO4 2' and Cl, sodium adsorption ratio(SAR). soluble sodium percentage(SSP), residual sodium carhonate(RSC) and hardness( i-li) were also calculated. The pH values of collected water samples ranged from 6.98 to 8..30 and were found to be 'suitable' for successful crop production. EC values graded the water samples as 'excellent' to 'good' classes. TDS values of3l water samples were graded as 'fresh water' with the exception in only 2 samples. Classification based on SAR, all the samples were of'excellcnt' class. The SAR values were within the range of 0.15 to 5.05. EC and SAR categorized the samples as 'low' 'medium' and 'higif salinity (Cl. C2 and 0) and low alkali hazard's (SI). combinedly expressed as CISI (3 samples). C2SI (28 samples) and C3SI (2 samples). On the basis of SSP all samples were excellenC and all water samples were rated as 'suitable' for Irrigation'. Hardness of water reflected that among the surface water 17 samples were found as 'moderately hard'. II samples were 'hard' and the rest 5 samples belonged to 'very hard'.Thc concentrations of total cations 1.86 to 17.36 me U' and anions 1.422 to 16.21 meL'1 contents of all water samples were not found to be harmful for field crops. l'he concentration of Fe of all the samples and Mn concentration of 31 samples (except sample no.9 near Ilazarihag and sample no.10 middle of' the liuriganga near Azimpur) were found 'suitable' for carbonated beverage. con fectionary. laundering. ice manufucture, tanning and textile industries. The results of ionic constituents Cl, Cu. Fe. NO3 and SO4 concentrations referred that 25 samples were found suitable for drinking and the rest samples were 'not suitable' for drinking. Mn and Cl statuses of all water were not suitable for livestock consumption. B, Fe, Cu. NOt and Zn contents of all samples would be suitable for livestock consumption. The pH vs SAL EC vs pl-{. EC vs TDS. EC vs lh. H1 vs IDS, SAR vs SSP. RSC vs 5SF, [C vs SSP, RSC vs Ht Ca vs HCO3 and Mg vs HCO3 combination showed significant correlation. And EC vs RSC and RSC vs 11T combination showed a negative significant correlation. On the contrary. the relationship between PAR vs SSP and p11 vs Hr were found insignificant.