Sediment clays are trapping heavy metals in urban lakes: An indicator for severe industrial and agricultural influence on coastal wetlands at the Mediterranean coast of Egypt

Amr E Keshta; Kamal H Shaltout; Andrew H Baldwin; Ahmed A Sharaf El-Din

doi:10.1016/j.marpolbul.2019.110816

Sediment clays are trapping heavy metals in urban lakes: An indicator for severe industrial and agricultural influence on coastal wetlands at the Mediterranean coast of Egypt

Mar Pollut Bull. 2020 Feb:151:110816. doi: 10.1016/j.marpolbul.2019.110816. Epub 2020 Jan 29.

Authors

Amr E Keshta¹, Kamal H Shaltout², Andrew H Baldwin³, Ahmed A Sharaf El-Din²

Affiliations

¹ Botany Department, College of Science, Tanta University, Tanta 31111, Egypt; Department of Environmental Science and Technology, College of Agriculture and Natural Resources, University of Maryland, College Park, MD 20742, USA. Electronic address: akeshta@umd.edu.
² Botany Department, College of Science, Tanta University, Tanta 31111, Egypt.
³ Department of Environmental Science and Technology, College of Agriculture and Natural Resources, University of Maryland, College Park, MD 20742, USA.

PMID: 32056609
DOI: 10.1016/j.marpolbul.2019.110816

Abstract

Coastal wetlands of the northern coast of Egypt have been impacted with higher loads of runoff, especially the large urbanized lakes of the Nile deltaic coast. Five urban lakes spanning the northern coast of Egypt (from east to west: Bardawil, Manzala, Burullus, Edku, and Mariut) were sampled for quantifying concentrations of heavy metals in their sediment and plant tissues. Sediment and plant tissues in lake Bardawil were the least contaminated, and the other lakes were moderately to highly polluted with Ni, Co, Cr, Pb, Zn, and Cu. Edku had the highest concentrations of Co, Cr, and Cu (19.83, 45.42 and 68.60 mg kg^-¹, respectively). The proportion of clay in sediment was significantly and positively correlated with Co and Ni in sediment (r = 0.7 and P ≤ 0.001), suggesting an important role of clay cation exchange capacity in the sorption of metals and removing them from the water column.

Keywords: Clay; Ecosystem services; Egypt; Eichhornia crassipes; Heavy metals; Urban lakes.

MeSH terms

Clay
Egypt
Environmental Monitoring*
Geologic Sediments
Lakes / chemistry
Metals, Heavy*
Water Pollutants, Chemical*
Wetlands

Substances

Metals, Heavy
Water Pollutants, Chemical
Clay