Spatial Distributions and Intrinsic Influence Analysis of Cr, Ni, Cu, Zn, As, Cd and Pb in Sediments from the Wuliangsuhai Wetland, China

Abstract

The spatial distributions of Cr, Ni, Cu, Zn, As, Cd and Pb (potentially toxic elements, PTEs) in sediments and intrinsic influence factors from the Wuliangsuhai wetland of the Hetao Irrigation District, China were studied in this work. The results showed that excluding Zn, the total contents of other PTEs were higher than the background values, of which As (39.26 mg·kg−1) and Cd (0.44 mg·kg−1) were six-fold and seven-fold higher, respectively. Especially, the high levels of Cd (70.17%), Pb (66.53%), and Zn (57.20%) in the non-residual fraction showed high bioavailability and mobility. It indicated that PTEs can enter the food chain more easily and produce much toxicity. Based on Igeo, ICF, and MRI, the contamination of As was the most serious in the middle areas (MDP) of the wetland, and its risk was up to moderately strong. Cd and Pb posed moderate and considerate risk, respectively. Furthermore, 29.50% and 55.54% risk contribution ratio of As and Cd, respectively, showed that they were the dominant contaminants. In addition, the positive correlation between sand, OM, and total contents and chemical fractions of PTEs by using PCM, RDA, and DHCA indicated that physicochemical properties could significantly influence the spatial distributions of PTEs. The work was useful for assessing the level of pollution in the study area and acquiring information for future and possible monitoring and remediation activities.

In situ, high-resolution evidence for the release of heavy metals from lake sediments during ice-covered and free periods

“…Consequently, processes of deposition, mixing, and removal of various elements at the SWI play a pivotal role in the translocation of pollutants. Previous research using the Diffusive Gradients in Thin films (DGT) technique at the SWI has indicated that high labile Mn concentrations in the overlying water, reaching up to 22.3 mg L −1 (Yuan et al, 2018), with sediments identified as sources of heavy metals such as Pb, Zn, and Cd, particularly in the weakly mixed zone (Wang and Wang, 2017;Zhang H. et al, 2022;Liu et al, 2023).…”

“…DGT has been widely employed as an in-situ passive sampling technique to assess the environmental metal chemistry at the SWI. The methodology has been extensively applied in various regions China, such as the Three Gorges Reservoir (Gao et al, 2018), in Lake Taihu (Yuan et al, 2018),in Lake Dianchi and WuliangSuhai (Wu et al, 2019;Li et al, 2022;Zhang H. et al, 2022;Zheng et al, 2022) in China. Nevertheless, limited research has been conducted on lakes in Northeast China, highlighting the need for increased focus on this geographical area.…”

Paenibacillus sedimenti sp. nov., isolated from freshwater wetland sediment

“…Due to rapid economic development, many wetlands or lakes in China have become eutrophic or polluted by heavy metal [21, 22]. A Paenibacillus -like bacterium was isolated from sediment of a heavy metal polluted wetland [23], where active anaerobic ammonium oxidation and denitrifying bacteria contributed to nitrogen removal [24]. Here, we report the taxonomic characterization of a Paenibacillus -like bacterium based on a comparison of a series of phenotypic, genotypic and chemotaxonomic characteristics with other closely related type strains within the genus Paenibacillus .…”

“…The content of DNA G+C is 39–60.7 mol % [8–20]. The major respiratory quinone is menaquinone-7 (MK-7), the major cellular fatty acid is anteiso-C 15 : 0 [8–29]. The members of the genus Paenibacillus contain diphosphatidylglycerol as the major polar lipid, and some strains also contain phosphatidylethanolamine and phosphatidylglycerol [9–14, 16–20].…”