Temporal effects of treated and untreated municipal sewage on the
cations – calcium (Ca), magnesium (Mg), hardness, sodium (Na) and
potassium (K), and anions – chlorides (Cl
$^-$
),
bicarbonates (HCO
$_3^-$
), carbonates
(CO
$_3^{2-}$
) and alkalinity of surface water of the
Buckingham canal were monitored across different seasons during premonsoon 2005
to post-monsoon – 2006 at Kalpakkam (Tamil Nadu) located on the east
coast of Indian peninsula. The concentrations of each of the cations and anions
were higher in the untreated sewage input zone than that of the treated sewage
input zone, and at the downstream higher than that of the upstream of the
outfall points of both the untreated as well as treated sewage, of the canal.
These parameters except K and alkalinity were higher in concentrations during
summer while all the cations and the anions were lower during monsoon. The
concentrations of K and alkalinity were higher during winter. Cluster analysis
based on the similarities of the cations and anions applied to the six sampling
points of the canal, grouped them into two clusters, one showing higher
pollution level and the other lower pollution levels of water.
