A comparative study of water quality in the peripheral rivers of Dhaka city

Abstract

This study examined the present status of surface water pollution and a
comparison of the quality of water in different seasons at different locations of
the major river, around the Dhaka City. Field investigation was started from
January, 2011 and sample collection was conducted six times at an interval of two
months up to December, 2011. The observed value of different water quality
parameters such as pH, DO, BOD, COD and TDS were compared with the
standards recommended by Department of Environment (DoE), Bangladesh and
United States Environmental Protection Agency (USEPA). A simple ANOVA and
Box-Cox study was also conducted to detect the variation of water quality in the
major rivers. The study revealed that during the dry season especially in the
months of December to February (winter), the higher values of parameters with
respect to the acceptable limits of DoE and USEPA standard indicate the
pollution of the river water samples and make the water unsuitable for various
uses. Comparisons of abundance values demonstrated high significant difference
(p < 0.05) between the mean concentrations of respective parameters except pH at
different locations in water source types. Water quality in Hagaribagh of
Buriganga river and the Tongi railway bridge stations of Tongi khal was
significantly more common polluted area than any other sites of selected water
sources as the largest amounts of toxic chemicals are released here by the
tannery and dyeing industries without any treatment.