TITLE:
Characterisation of Temperate Urban Lacustrine Surface-Sediments for Minerals and Metals in Comparison with Geochemical Indices and Sediment Quality Criteria
AUTHORS:
Umar Nazir, Anisa B. Khan
KEYWORDS:
Bicarbonate, Contamination, Fluvial, Monitoring, Trophic Index
JOURNAL NAME:
Journal of Environmental Protection,
Vol.9 No.10,
September
10,
2018
ABSTRACT: The present surface sediment assessment in two
temperate lacustrine ecosystems in the region of anthro-urban intensification
in less than a century of progressive human history identifies ecosystem
responses through space-time monitoring of variable spectrum and their
gradients. Sediments have almost no outliers in box-plots across the select
sites that suggest their tranquil nature. But temporal fluctuations in pH,
bicarbonates, conductivity, OC, OM, TN and C/N can be visualised during Ca-Si
dominance. The estimated percentage elemental composition of surface sediments
on dry weight basis revealed the order Si > Ca > Mg > K > Na > P > S > Cl. Besides, the micro and trace
element quantification represent the descending series of Fe > Al > Zn
> Mn > Cu > Cr > Ni > Co > As > Sn > Pb > Cd while
Hg and Se remained below detection level (BDL). Sediment pH remained on the
basic side but slight acidic nature is noticed during late summer. Significant
correlation occurs for conductivity with organic C and organic matter (p geo)
scale labels “Unpolluted” to “Highly Polluted” element groups in sediments. The
construal of Contamination Factor differentiates between “Contaminated” and
“Uncontaminated” score of elements. Integrated Pollution Index (IPI) and
Pollution Load Index (PLI) also categorize the sites and lakes. Sediment
Quality Guidelines (SQG’s) when compared to observed mean values for various
elements point to pollution status and associated ecological risks involved.