Distribution of heavy metals in the core sediments of a tropical wetland system

Abstract

Five sediment cores from the fresh water region of the Vembanad wetland system were studied for the trace element contents The average concentration of iron, manganese, nickel, copper, zinc, cadmium, lead, mercury and chromium were determined. The core samples were collected using gravity type corer, digested with a mixture of nitric acid and perchloric acid and analyzed by atomic absorption spectrophotometry. Heavy metals such as iron, copper, nickel and zinc reported enrichment towards the surface of the core sediment sample collected from the centre of the lake. Lead, cadmium and mercury showed uniform distribution through out the core. Quality of the sediments were evaluated based on sediment quality guidelines, pollution load index, sum of toxic units and with effect range low/effect range median and threshold effect level/probable effect level values of Environmental Protection Agency guidelines. The degree of contamination for each station was determined. The concentration of different heavy metals has been compared with the world average concentration of shale values. Results of the analysis showed that Vembanad lake is facing serious metal pollution with increased rate of deposition.

Comparative analysis of heavy metal concentration in secondary treated wastewater irrigated soils cultivated by different crops

“…Rusan et al (2007) rightly noted that there is inconsistency in research findings on the impact of wastewater irrigation on soil micronutrients and heavy metals. However, results in this study tally with the findings of some previous studies, including: 1) the build-up of heavy metals such as Cd, Hg, Ni and Pb and micronutrients such as Cu, Fe, Mn and Zn in the upper layers of the soil or sediment cores (Mancino and Pepper, 1992;Rusan et al, 2007;Harikumar et al, 2009); 2) increases in soil Al, Fe and Mn with wastewater irrigation (Mohammad and Mazahreh, 2003); 3) variable and inconsistent responses of soil micronutrients under different crop types; and 4) the significance of soil textural differences in influencing the accumulation of heavy metals and micronutrients in soils under wastewater irrigation (Ivan and Earl, 1972;Donahue et al, 1977).…”

Assessment of Metals Concentration in Water, Sediment and Macrophyte Plant Collected from Lake Hawassa, Ethiopia

“…Metals concentrations of Zn, Cr, Cr and Pb from Lake Hawassa sediment as compared to the probable-effects-level (PEL) guidelines for toxic biological effects established and sediment-quality guidelines by USEPA [31], the present results revealed that metals concentration of sediment showed higher than the level of those elements set by the guidelines. Moreover, metals concentrations in the sediment including mercury exceeded the maximum acceptable levels cited by Frances [13].…”

An Assessment of Heavy Metals Contents in the Soil around a Cement Factory in Ewekoro, Nigeria Using Pollution Indices

“…A PLI value greater than 1 is polluted, whereas a PLI value less than 1 indicates no pollution [22].…”