In recent years, many industrial enterprises located in the urban centers of China have been relocated owing to the rapid increase in urban development. At the sites abandoned by these enterprises, volatile organic compounds have frequently been detected, sometimes at high concentrations, particularly at sites abandoned by chemical manufacturing enterprises. With the redevelopment of sites and changes in land-use type associated with these sites, substantial amounts of contaminated soils now require remediation. Since China is a developing country, soil remediation warrants the usage of techniques that are suitable for addressing the unique challenges faced in this country. Land shortage is a common problem in China; the large numbers of contaminated sites, tight development schedules, and limited financial resources necessitate the development of cost-effective methods for land reclamation. Mechanical soil aeration is a simple, effective, and low-cost soil remediation technique that is particularly suitable for the remediation of large volatile organic compound-contaminated sites. Its effectiveness has been confirmed by conducting laboratory studies, pilot tests, and full-scale projects. This study reviews current engineering practice and developmental trends of mechanical soil aeration and analyzes the advantages and disadvantages of this technology for application in China as an emerging soil remediation market. The findings of this study might aid technology development in China, as well as assist other developing countries in the assessment and implementation of costeffective hazardous waste site soil remediation programs.
Many studies have focused on environmental estrogen-related diseases. However, no consistent gene markers or signatures for estrogenicity have been discovered in mammals. This study investigated the estrogenic effects of 17β-estradiol on the prostate in immature male mice. Consistent U-shaped responses were seen in bodyweight, ventral prostate epithelial morphology, and miRNA expression levels. Specifically, most estradiol regulated miRNAs were downregulated at low doses of estradiol (0.2 and 2 mg·kg–1), and whose expression returned to the control level at a larger dose (200 mg·kg–1). The function of these regulated miRNAs is related to the prostate cancer and PI3K-Akt signaling pathways, which is consistent with the function of estradiol. Furthermore, the miRNA-processing machinery, Drosha, in the prostate was also regulated in a similar pattern, which could be a part of the U-shaped miRNA expression mechanism. All of these data indicate that the prostate is a reliable organ for evaluating estrogenic activity and that the typical nonmonotonic dose-response relationship could be used as a novel biomarker for estrogenicity.
• Emission of microbe from local environments is a main source of bioaerosols.• Regional transport is another important source of the bioaerosols.• There are many factors affecting the diffusion and transport of bioaerosols.• Source identification method uncovers the contribution of sources of bioaerosols. Recent pandemic outbreak of the corona-virus disease 2019 (COVID-19) has raised widespread concerns about the importance of the bioaerosols. They are atmospheric aerosol particles of biological origins, mainly including bacteria, fungi, viruses, pollen, and cell debris. Bioaerosols can exert a substantial impact on ecosystems, climate change, air quality, and public health. Here, we review several relevant topics on bioaerosols, including sampling and detection techniques, characterization, effects on health and air quality, and control methods. However, very few studies have focused on the source apportionment and transport of bioaerosols. The knowledge of the sources and transport pathways of bioaerosols is essential for a comprehensive understanding of the role microorganisms play in the atmosphere and control the spread of epidemic diseases associated with them. Therefore, this review comprehensively summarizes the up to date progress on the source characteristics, source identification, and diffusion and transport process of bioaerosols. We intercompare three types of diffusion and transport models, with a special emphasis on a widely used mathematical model. This review also highlights the main factors affecting the source emission and transport process, such as biogeographic regions, land-use types, and environmental factors. Finally, this review outlines future perspectives on bioaerosols. 相似文献
ABSTRACTLow-carbon development is an essential measure to combat climate change, and the establishment of low-carbon standards is an important means to achieve low-carbon development. Due to the differences in size and development level among counties of China, the applicability and fairness of county-level low-carbon standards are very important in this country. This study analyzed the trends of county-level carbon emissions in China, defined the peak value of carbon emissions per capita, summarized the characteristics of existing low-carbon standards, and proposed a fair county-level low-carbon standard based on carbon emissions per capita. The results of our analysis suggest that, under the constraints of carbon emissions reduction policies, China’s carbon emissions per capita will tend towards a stable range. Additionally, by referring to predictions results of the peak value of China’s carbon emissions per capita, it was determined that, in low-carbon development targets, China’s county-level carbon emissions per capita should be set within the range of 2–4 tons. Besides setting low-carbon standards, the Chinese government and private enterprises should develop low-carbon technologies as soon as possible and innovate management models to achieve the win–win situation of simultaneous economic growth and carbon emissions reduction. 相似文献
The combination of two bacteria (Bacillus sp. PY1 and Sphingomonas sp. PY2) and a fungus (Fusarium sp. PY3), isolated from contaminated soils near a coking plant, were investigated with respect to their capability to degrade pyrene and volatilize arsenic. The results showed that all strains could use pyrene and arsenic as carbon and energy sources in a basal salts medium (BSM), with the combined potential to degrade pyrene and volatilize arsenic. Bacillus sp. PY1, Sphingomonas sp. PY2 and Fusarium sp. PY3 were isolated from the consortium and were shown to degrade pyrene and volatilize arsenic independently and in combination. Fungal-bacterial coculture has shown that the most effective removal of pyrene was 96.0% and volatilized arsenic was 84.1% after incubation in liquid medium after 9 days culture, while bioremediation ability was 87.2% in contaminated soil with 100 mg·kg-1 pyrene. The highest level of arsenic volatilization amounted to 13.9% of the initial As concentration in contaminated soil after 63 days. Therefore, a synergistic degradation system is the most effective approach to degrade pyrene and remove arsenic in contaminated soil. These findings highlight the role of these strains in the bioremediation of environments contaminated with pyrene and arsenic. 相似文献