A 110 Year Sediment Record of Polycyclic Aromatic Hydrocarbons Related to Economic Development and Energy Consumption in Dongping Lake, North China

A sedimentary record of the 16 polycyclic aromatic hydrocarbon (PAH) pollutants from Dongping Lake, north China, is presented in this study. The influence of regional energy structure changes for 2–6-ring PAHs was investigated, in order to assess their sources and the impact of socioeconomic developments on the observed changes in concentration over time. The concentration of the ΣPAH16 ranged from 77.6 to 628.0 ng/g. Prior to the 1970s, the relatively low concentration of ΣPAH16 and the average presence of 44.4% 2,3-ring PAHs indicated that pyrogenic combustion from grass, wood, and coal was the main source of PAHs. The rapid increase in the concentration of 2,3-ring PAHs between the 1970s and 2006 was attributed to the growth of the urban population and the coal consumption, following the implementation of the Reform and Open Policy in 1978. The source apportionment, which was assessed using a positive matrix factorization model, revealed that coal combustion was the most important regional source of PAHs pollution (>51.0%). The PAHs were mainly transported to the site from the surrounding regions by atmospheric deposition rather than direct discharge.

Escherichia coli harboring mcr-1 on a Novel Plasmid in a Mink

Background: Antimicrobial resistant Escherichia coli from mink can be transmitted to human through water environment. Therefore, it is necessary to routinely detect the presence of antimicrobial resistance genes of mink. Methods: In the current study, we described the characterization of an mcr-1-positive Escherichia coli isolate from a dead mink in Dongping Lake, China. The molecular characterization of plasmids was also investigated. Results: The strain was resistant to colistin, but it remained susceptible to several other agents, including amikacin, piperacillin-tazobactam and all carbapenems. Escherichia coli Mink_1 belonged to sequence type 140. Whole genome sequencing(WGS) showed that two plasmid, pM1mcr and pM1ctx, coexisted in the same bacterial. Blast and phylogenetic tree imply that epidemic plasmids are vehicles for the dissemination of colistin resistance genes among the Enterobacterale. Conclusion: Restrictive and rational use of antibiotics in animal husbandry should be taken to reduce the dissemination of mcr-1.

Surface Sediment Diatom Assemblages Response to Water Environment in Dongping Lake, North China

The relationship between the diatom taxa preserved in surface lake sediments and environmental variables in Dongping Lake was explored using multivariate statistical methods. The statistical analysis showed that the lake was eutrophicated in all seasons. Transparency, chlorophyll a (Chla) and total phosphorus (TP) were the dominant environmental factors in spring and summer, and NH4+-N and chemical oxygen demand (COD) were the dominant environmental factors in autumn and winter. Sixteen genera and 43 species of diatom were found in the surface sediments, and the dominant diatom genera were Aulacoseira, Ulnaria, Cyclotella, Navicula and Fragilaria. A redundancy analysis (RDA) and Monte Carlo permutation 20 test revealed that COD, pH, TP, conductivity and transparency were significant factors influencing diatom assemblage change, meaning that the distribution of the diatom assemblages were mostly influenced by nutrient composition, light intensity and ion concentrations.

Impact Assessment of Eastern Route of South-to-North Water Diversion Project Operation on Water Environmental of Dongping Lake

The Eastern Route of the South-to-North Water Diversion Project is a national strategic measure to improve the water supply conditions of the cities along the route, Jiaodong and Huaibei regions. However, the Water Diversion Project not only brings social and economic benefits, but also changes the hydrological situation and ecological environment of water source area, transfer area and receiving area. In this paper, Dongping Lake is selected as the research object. By using the analytic hierarchy process and fuzzy evaluation method, the index system of the impact assessment of the Eastern route project on the water environment of Dongping Lake is constructed, and a multi-level fuzzy evaluation model is established to conduct quantitative and qualitative research on the impacts of hydrology, meteorology, water ecological environment, soil and other aspects as well as ecological and economic compensation. The analysis results show that the operation of the Eastern route project has brought some negative effects on Dongping Lake, mainly reflected in the aspects of soil, ecological compensation, hydrology and meteorology, and the negative effects on the water ecological environment are light. By studying the impact of the Eastern route project on the water environment of Dongping Lake, this paper aims to improve the environmental impact assessment system for the water receiving area of the Eastern Route of the South-to-North Water Diversion Project, and to provide reference for the research on the environmental impact assessment system for other water diversion projects in China.