Polycyclic aromatic hydrocarbon and n-alkane pollution characteristics and structural and functional perturbations to the microbial community: a case-study of historically petroleum-contaminated soil

Characterization of the typical petroleum pollutants, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes, and indigenous microbial community structure and function in historically contaminated soil at petrol stations is critical. Five soil samples were collected from a petrol station in Beijing, China. The concentrations of 16 PAHs and 31 n-alkanes were measured by gas chromatography-mass spectrometry. The total concentrations of PAHs and n-alkanes ranged from 973 ± 55 to 2667 ± 183 μg/kg and 6.40 ± 0.38 to 8.65 ± 0.59 mg/kg (dry weight), respectively, which increased with depth. According to the observed molecular indices, PAHs and n-alkanes originated mostly from petroleum-related sources. The levels of ΣPAHs and the total toxic benzo[a]pyrene equivalent (ranging from 6.41 to 72.54 μg/kg) might exert adverse biological effects. Shotgun metagenomic sequencing was employed to investigate the indigenous microbial community structure and function. The results revealed that Proteobacteria and Actinobacteria were the most abundant phyla, and Nocardioides and Microbacterium were the important genera. Based on COG and KEGG annotations, the highly abundant functional classes were identified, and these functions were involved in allowing microorganisms to adapt to the pressure from contaminants. Five petroleum hydrocarbon degradation-related genes were annotated, revealing the distribution of degrading microorganisms. This work facilitates the understanding of the composition, source, and potential ecological impacts of residual PAHs and n-alkanes in historically contaminated soil.

     

Combined toxic impacts of thiamethoxam and four pesticides on the rare minnow (Gobiocypris rarus)

To examine pesticide mixture toxicity to aqueous organisms, we assessed the single and combined toxicities of thiamethoxam and other four pesticides (chlorpyrifos, beta-cypermethrin, tetraconazole, and azoxystrobin) to the rare minnow (Gobiocypris rarus). Data from 96-h semi-static toxicity assays of various developmental phases (embryonic, larval, juvenile, and adult phases) showed that beta-cypermethrin, chlorpyrifos, and azoxystrobin had the highest toxicities to G. rarus, and their LC₅₀ values ranged from 0.0031 to 0.86 mg a.i. L^?1, from 0.016 to 6.38 mg a.i. L^?1, and from 0.39 to 1.08 mg a.i. L^?1, respectively. Tetraconazole displayed a comparatively high toxicity, and its LC₅₀ values ranged from 3.48 to 16.73 mg a.i. L^?1. By contrast, thiamethoxam exhibited the lowest toxic effect with LC₅₀ values ranging from 37.85 to 351.9 mg a.i. L^?1. Rare minnow larvae were more sensitive than embryos to all the pesticides tested. Our data showed that a pesticide mixture of thiamethoxam–tetraconazole elicited synergetic toxicity to G. rarus. Moreover, pesticide mixtures containing beta-cypermethrin in combination with chlorpyrifos or tetraconazole also had synergetic toxicities to fish. The majority of pesticides are presumed to have additive toxicity, while our data emphasized that the concurrent existence of some chemicals in the aqueous circumstance could cause synergetic toxic effect, leading to severe loss to the aqueous environments in comparison with their single toxicities. Thence, the synergetic impacts of chemical mixtures should be considered when assessing the ecological risk of chemicals.

     

The catalytic performance of Cu46Zr47-xAl7Yx amorphous ribbons in the degradation of AO II dye wastewater

Environmental Science and Pollution Research - Metallic glasses (MGs) with unique disordered atomic stacking structures exhibit excellent catalytic performance in wastewater treatment. The...     

The permeability of dredged material-bentonite backfills

Environmental Science and Pollution Research - Extensive attention has been paid to the treatment and disposal of dredged material, and there is a need to clarify the feasibility of recycling...     

Exploring soil erosion trajectories and their divergent responses to driving factors: a model-based contrasting study in highly eroded mountain areas

Environmental Science and Pollution Research - Soil erosion threatens environmental sustainability worldwide. Exploring the trajectories of soil erosion and associated drivers is of great...     

Effects of tea polyphenols on the activities of antioxidant enzymes and the expression of related gene in the leaves of wheat seedlings under salt stress

Environmental Science and Pollution Research - Longchun 30, a new wheat variety, was used to investigate seedling growth, element absorption, and antioxidant response under 150 mM NaCl and tea...     

我在找约翰叔叔

卡特里娜飓风袭击墨西哥湾地区后,志愿者组织“寻人者”整理了25家网站和信息栏的数据,迅速建立了65万名无家可归者的数据目录,可供网上查询。自从该网站开通以来,登录该网站寻人的用户已经超过 100万人次。     

公共危机管理中的政府机构

公共危机状态下的管理,政府需要动员和统一调配多方面的资源,管理必须具有权威性,进行有效协调和快速行动,这就要求组建统一的领导指挥系统,通过综合协调部门和职能组织系统,最大限度地减少公共危机发生的可能性,或快速、有效地应对危机．最大限度地减少损失。指挥系统的建设公共危机给政府带来突发性、紧急性、危害性。急需要建立权威的、统一的领导指     

Two-step harmless treatment of secondary aluminum dross (SAD) by vacuum distillation and alkaline roasting

Journal of Material Cycles and Waste Management - Secondary aluminum dross (SAD) is classified as hazardous waste by many countries in the world because it contains a large number of toxic and...     

Contextual and organizational factors in sustainable supply chain decision making: grey relational analysis and interpretative structural modeling

Environment, Development and Sustainability - Sustainable supply chain emerges as a major business trend essential to long-term competitive advantage. Relevant corporate decisions concern a broad...