Monitoring and assessment of heavy metal contamination in surface water and sediment at Old Brahmaputra River, Bangladesh Presenter Md. Simul Bhuyan Institute of Marine Science and Fisheries, University of Chittagong, Bangladesh. Co-Authors Muhammad Abu Bakar, Md. Rashed- Un-Nabi, Venkatramanan Senapathi, Sang Yong Chung, Md. Shafiqul Islam

Introduction

What is metal?

Effects of metal

Objective Determination of heavy metals concentrations in water and sediment

Mathodology

Study site The study was conducted in the Old Brahmaputra River Instrument used The heavy metals were determined by Atomic Absorption Spectrophotometer (AAS) Software used 1.SPSS v.22 2.PRIMER v.6

Results and Discussion

Concentration of heavy metal in water

Fig. Mean concentrations (mg/l) of heavy metals in water during three seasons.

Heavy metals ECR, 1997 WHO, 2004 USEPA, 2006 EC, 1998EPA, 1986EPA, 2002 Present study Pb Cd Cr Cu Hg Al Ni Co Zn Mn Table. The heavy metal concentrations (mg/l) in water and it's comparison with international standards.

River Pb Cd Cr Cu Hg AlNi Co Zn Mn References Old Brahmaputra River Present study Buriganga Ahmad et al Buriganga Bhuiyanet al Balu Mokaddes et al Dhaleshwari Ahmed et al Dhaleshwari Ahmed et al Khiru Rashid et al Karatoa Trace Trace Trace0.101 Zakir et al Karnofuly Islam et al MeghnaBDL BDL Hassan et al Shitalakhya Mokaddes et al Shitalakhya Islam et al Turag Mokaddes et al Table. The heavy metal concentrations (mg/l) in water and it's comparison with other rivers.

Concentration of heavy metal in sediment

Fig. Mean concentrations (mg/kg) of heavy metals in sediment during three seasons.

Heavy metals WHO, 2008 WHO, 2004USEPA, 1999FAO, 1985Present study Pb Cd Cr Cu Hg Al Ni Co Zn Mn – Table. Comparison of the observed values of heavy metals in the sediments of the Old Brahmaputra River with international standard.

River Pb Cd Cr Cu Hg AlNi Co Zn Mn References Old Brahmaput ra River Present study Buriganga Ahmad et al Buriganga Saha and Hossain, 2011 Buriganga Mohiuddin et al Bangshi Rahman et al Dhaleshwari Ahmed et al Khiru Rashid et al Karnofuly Islam et al Karatoa Islam et al Meghna Hassan et al Shitalakhya Islam et al Shitalakhya Islam et al Turag Banu et al Table. The heavy metal concentrations (mg/kg) in sediment and it's comparison with other rivers.

Anthropogenic intrusions of metals in water and sediment

Fig. Percentage of similarity among heavy metals in sediment during different seasons.[ O.C=Organic Carbon; O.M=Organic Matter]

Component Eigenvalues (0.6) PC 1PC 2 Pb Cd Cr Cu Hg Al Ni Co Zn Mn %Silt %Sand %Clay %O.C %O.M Eigen value % Total variance Cumulative % Table. Component matrix of two factors model with strong to moderate loadings in sediment

%Silt%Sand%Clay%Organic Carbon%OrganicMatter Pb Cd Cr Cu Hg Al Ni Co Zn Mn Table. Correlation matrix of heavy metals in sediment Very strong linear relationships Strong linear relationship

Conclusion

Most of the metals exceeded the permissible limit set of standards. Grain size and organic matter acted as efficient scavengers for metals in sediments. PCA analysis, Cluster analysis and Correlation matrix suggested the contribution of metals in water and sediments were derived from the anthropogenic origin in addition to lithogenic sources. Further studies are also needed on metal speciation and effects on metal uptake by human and organisms.

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