Browsing by Author "Islam, Shriful"

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    A comparative study on dispersivity of Arsenic among Surma, Sari and Volaganj sand
    (BRAC University, 2011) Islam, Shriful; Rahman, M.S.; Das, R.K.
    Transport mechanism of Arsenic (As) through the Surma, Sari and Volaganj sand is the prime concern of this study. Three column leaching tests were performed to find the dispersivity property of As. Numerous physical properties of these sand samples were determined and it shows Volaganj sand is most permeable. From the collected data experimental and theoretical breakthrough curve (BTC) were prepared and compared with each other. The value of dispersion coefficient and Index of dispersion were calculated. Dispersion coefficient (773.763cm2/min) and index of dispersion (844.3cm2/min) was higher for Surma sand. The leaching rate was found higher for higher pore water velocity of the Volaganj sand. The study also reveals that there is a significant difference between theoretical and experimental breakthrough curve. So not only convection/dispersion but also other processes such as adsorption, reaction with other compound are associated with the movement of arsenic through the sand medium.
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    Application of sensitivity analysis in self purification of the Surma River , Bangladesh
    (BRAC University, 2010) Islam, Shriful; Alam, Md. J.B.; Haque, Md. A.
    The rivers which flow through a city show an appreciable decline in water quality but they are often difficult to specify the exact cause of deterioration. Also the treatment of pollution of river is very troublesome. This study finds the treatment efficiency of the Surma River by its self purification capacity due to the pollution through discharges of choras (small canal), industrial wastewater discharges, and human excreta disposal. The sensitivity analysis by Streeter-Phelps Oxygen-sag equation is used to find the treatment efficiency and the corresponding sensitivity values for some selected pollution parameters were also determined. The Java software was used to find the treatment efficiency and to show the relation between treatment efficiency and those selected parameters.