Heavy metals in the riverbed surface sediment of the Yellow River, China

Abstract

One hundred and eleven riverbed surface sediment (RSS) samples were collected to determine the heavy metal concentration throughout the Inner Mongolia reach of the Yellow River (IMYR), which has been subjected to rapid economic and industrial development over the past several decades. Comprehensive analysis of heavy metal contamination, including the enrichment factor, geo-accumulation index, contamination factor, pollution load index, risk index, principal component analysis (PCA), hierarchical cluster analysis (HCA), and Pearson correlation analysis, was performed. The results demonstrated that a low ecological risk with a moderate level of heavy metal contamination was present in the IMYR due to the risk index (RI) being less than 150 and the pollution load index (PLI) being above 1, and the averaged concentrations of Co, Cr, Cu, Mn, Ni, Ti, V, and Zn in the RSS, with standard deviations, were 144 ± 69, 77.91 ± 39.28, 22.95 ± 7.67, 596 ± 151, 28.50 ± 8.01, 3793 ± 487, 69.11 ± 18.44, and 50.19 ± 19.26 mg kg, respectively. PCA, HCA, and Pearson correlation analysis revealed that most of the RSS was heavily contaminated with Zn, Ni, and Cu, due to the influence of anthropogenic activities; moderately contaminated with Ti, Mn, V and Cr because of the dual influence of anthropogenic activities and nature; and slightly to not contaminated with Co because it occurs mainly in the bordering desert areas. Graphic abstract ᅟ.

Assessment of heavy metal pollution in sediments of the Sonora River basin impacted by mining activities

“…In the Bacanuchi River, the minimum and maximum metal concentrations were (mg/kg): Cd and Pb (BDL), Cr (BDL-2), Cu (1-13), Fe (127-245), Mn (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), Ni (BDL-7), and Zn (3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Metal mobility was as follows: Ni > Zn > Cr = Cu.…”

“…Heavy metals are introduced to aquatic environments naturally (soil and rock leaching and volcanic eruptions) but also anthropogenically (agricultural, industrial, and mining activities) 2 . When these pollutants are released into the environment, they enter the atmosphere, undergo hydrological circulation, and are finally deposited in riverbeds, reservoirs, and river deltas 3 . Naturally, sediments absorb a wide variety of pollutants, such as heavy metals, in their structure and surface.…”

“…2 When these pollutants are released into the environment, they enter the atmosphere, undergo hydrological circulation, and are finally deposited in riverbeds, reservoirs, and river deltas. 3 Naturally, sediments absorb a wide variety of pollutants, such as heavy metals, in their structure and surface. High levels of heavy metals in sediments may represent an anthropogenic source of pollution.…”

Ecological and health risk assessment of potentially toxic elements in Ewaso Nyiro River surface water, Kenya

“…PCA is a data reduction technique that reduces number of variables to a smaller set of scores called components without losing much of primary data [15]. Varimax rotation was employed in current analysis since variables were presumed to be uncorrelated [33].…”

Contamination Assessment of Heavy Metals in Sediment Cores from De Montigny Lake around Siscoe-Sullivan Former Mining Sites, Val-d’Or, Canada

“…where metal is entirely crystallized in the sediment while the higher FE values to 1.5 or 2 suggest anthropogenic sources (Garcia et al, 2008;Abreu et al, 2016). According to the EF of an element, Loska et al (2004) and Guan et al (2016) classified the enrichment factor (EF) into five levels: no or slight enrichment (EF < 2), moderate enrichment (2 ≤ EF < 5), significant enrichment (5 ≤ EF < 20), high enrichment (20 ≤ EF < 40) and extremely high enrichment (EF > 40). (2 < Igeo ≤ 3), moderately contaminated to strongly contaminated; Class 4 (3 < Igeo ≤ 4), strongly contaminated; Class 5 (4 < Igeo ≤ 5), strongly contaminated to extremely contaminated; and Class 6 (Igeo > 5), extremely contaminated (Müller, 1979;Ji et al, 2015;Dai et al, 2018;Liu et al, 2021).…”