Cytotoxicity of the soluble and insoluble fractions of atmospheric fine particulate matter

Inhaled atmospheric fine particulate matter(PM_(2.5)) includes soluble and insoluble fractions,and each fraction can interact with cells and cause adverse effects.PM_(2.5) samples were collected in Jinan,China,and the soluble and insoluble fractions were separated.According to physiochemical characterization,the soluble fraction mainly contains watersoluble ions and organic acids,and the insoluble fraction mainly contains kaolinite,calcium carbonate and some organic carbon.The interaction between PM_(2.5) and model cell membranes was examined with a quartz crystal microbalance with dissipation(QCM-D) to quantify PM_(2.5) attachment on membranes and membrane disruption.The cytotoxicity of the total PM_(2.5) and the soluble and insoluble fractions,was investigated.Negatively charged PM_(2.5) can adhere to the positively charged membranes and disrupt them.PM_(2.5)also adheres to negatively charged membranes but does not cause membrane rupture.Therefore,electrostatic repulsion does not prevent PM_(2.5) attachment,but electrostatic attraction induces remarkable membrane rupture.The human lung epithelial cell line A549 was used for cytotoxicity assessment.The detected membrane leakage,cellular swelling and blebbing indicated a cell necrosis process.Moreover,the insoluble PM_(2.5) fraction caused a higher cell mortality and more serious cell membrane damage than the soluble fraction.The levels of reactive oxygen species(ROS) enhanced by the two fractions were not significantly different.The findings provide more information to better understand the mechanism of PM_(2.5) cytotoxicity and the effect of PM_(2.5) solubility on cytotoxicity.     

Metabolomic modulations in a freshwater microbial community exposed to the fungicide azoxystrobin

An effective broad-spectrum fungicide, azoxystrobin (AZ), has been widely detected in aquatic ecosystems, potentially affecting the growth of aquatic microorganisms. In the present study, the eukaryotic alga Monoraphidium sp. and the cyanobacterium Pseudanabaena sp. were exposed to AZ for 7 days. Our results showed that 0.2–0.5 mg/L concentrations of AZ slightly inhibited the growth of Monoraphidium sp. but stimulated Pseudanabaena sp. growth. Meanwhile, AZ treatment effectively increased the secretion of total organic carbon (TOC) in the culture media of the two species, and this phenomenon was also found in a freshwater microcosm experiment (containing the natural microbial community). We attempted to assess the effect of AZ on the function of aquatic microbial communities through metabolomic analysis and further explore the potential risks of this compound. The metabonomic profiles of the microcosm indicated that the most varied metabolites after AZ treatment were related to the citrate cycle (TCA), fatty acid biosynthesis and purine metabolism. We thereby inferred that the microbial community increased extracellular secretions by adjusting metabolic pathways, which might be a stress response to reduce AZ toxicity. Our results provide an important theoretical basis for further study of fungicide stress responses in aquatic microcosm microbial communities, as well as a good start for further explorations of AZ detoxification mechanisms, which will be valuable for the evaluation of AZ environmental risk.     

Simulation of a 100-MW solar-powered thermo-chemical air separation system combined with an oxy-fuel power plant for bio-energy with carbon capture and storage (BECCS)

The combination of concentrated solar power–chemical looping air separation (CSP-CLAS) with an oxy-fuel combustion process for carbon dioxide (CO₂) capture is a novel system to generate electricity from solar power and biomass while being able to store solar power efficiently. In this study, the computer program Advanced System for Process Engineering Plus (ASPEN Plus) was used to develop models to assess the process performance of such a process with manganese (Mn)-based oxygen carriers on alumina (Al₂O₃) support for a location in the region of Seville in Spain, using real solar beam irradiance and electricity demand data. It was shown that the utilisation of olive tree prunings (Olea europaea) as the fuel—an agricultural residue produced locally—results in negative CO₂ emissions (a net removal of CO₂ from the atmosphere). Furthermore, it was found that the process with an annual average electricity output of 18 MW would utilise 2.43% of Andalusia’s olive tree prunings, thereby capturing 260.5 k-tonnes of CO₂, annually. Drawbacks of the system are its relatively high complexity, a significant energy penalty in the CLAS process associated with the steam requirements for the loop-seal fluidisation, and the gas storage requirements. Nevertheless, the utilisation of agricultural residues is highly promising, and given the large quantities produced globally (~?4 billion tonnes/year), it is suggested that other novel processes tailored to these fuels should be investigated, under consideration of a future price on CO₂ emissions, integration potential with a likely electricity grid system, and based on the local conditions and real data.

     

Can a low-carbon development path achieve win-win development: evidence from China’s low-carbon pilot policy

Mitigation and Adaptation Strategies for Global Change - Low-carbon pilot (LCP) policy aims to not only achieve economic development but also address climate change problems in China. With a...     

发光细菌生物毒性抑制率优化研究

发光细菌生物毒对水生生态环境有极大的破坏作用,为保护水体环境,提出发光细菌生物毒性抑制率优化研究。完成测试样品调制;设置菌悬液特征参数,利用pH、RLU及D600进行同步检测,完成发光细菌生物毒性重现;分析磺胺类药品于根际土壤的形态分布和生态毒性,完成发光细菌生物毒性抑制率优化研究。实验证明,三种磺胺类药品对发光细菌生物毒性的相对抑制率都小于30%,为低毒性;其中有机溶剂对发光细菌生物毒性的抑制率最大,水溶态较大,结合态最小。     

旅游风景区大型体育赛事的环境保护措施研究

结合旅游风景区举办大型体育赛事对环境的危害性,从减少污染排放源、从源头治理污染、加大管理层的监管力度等三方面进行环境污染监控管理。采用统计分析方法对环保治理效果进行量化评估,分析旅游风景区举办大型体育赛事期间的空气污染指数、废弃物排放数量以及水质污染情况,结合分组样本检验方法进行环保措施的有效性评价,并根据实际情况制定最优的环保措施,实现对旅游风景区的全方面环境治理,确保举办体育赛事对旅游景区的生态环境污染影响降到最低。