非水液相混合有机污染物的过冷液体溶解度间接测量

存在于混合物中的有机污染物是现代生活环境中常见的危害性较高的污染物。有机物过冷液体溶解度不仅是环境科学研究领域的重要概念,也是环境监测、环境质量评价、制定污染治理方案所需要的重要参数。由于过冷液体溶解度无法通过常规的实验方法进行测量,只能借助热力学计算取得。但是已有的热力学参数欠缺、精度不够,很多有机物的过冷液体溶解度或者无法准确计算,或者差异巨大。针对非水液相混合有机污染物中过冷液体溶解度取值问题,本文提出了一种测量过冷液体溶解度的实验方法,即采用批处理实验在不同摩尔分数点取得该点的平衡浓度,根据实验结果将不同摩尔分数点的平衡浓度外推(依线性或者非线性规律)至摩尔分数为一时,得到值为过冷液体溶解度。本文对对几种多环芳香烃进行了实验研究,并将实验结果的与其它方法得到的数值进行比较。结果与已经发表数值吻合,证实该方法的准确性和可靠性。同时也点评了该方法的局限性及应用前景。     

Plastic pollution: A focus on freshwater biodiversity

Plastics are dominant pollutants in freshwater ecosystems worldwide. Scientific studies that investigated the interaction between plastics and freshwater biodiversity are incipient, especially if compared to the marine realm. In this review, we provide a brief overview of plastic pollution in freshwater ecosystems around the world. We found evidence of plastic ingestion by 206 freshwater species, from invertebrates to mammals, in natural or semi-natural ecosystems. In addition, we reported other consequences of synthetic polymers in freshwater ecosystems—including, for instance, the entanglement of animals of different groups (e.g., birds). The problem of plastic pollution is complex and will need coordinated actions, such as recycling programs, correct disposal, stringent legislation, regular inspection, replacement of synthetic polymers with other materials, and ecological restoration. Current information indicates that the situation in freshwater ecosystems may be as detrimental as the pollution found in the ocean, although highly underappreciated.Supplementary InformationThe online version of this article (10.1007/s13280-020-01496-5) contains supplementary material, which is available to authorized users.     

Diffusion test of 20 kinds of waste molten slags and competitive materials

“Waste molten slag” is a glass-like material produced by the vitrification of solid waste or solid waste incineration residue. When using slags of this kind in a natural environment, their impact is anticipated to be at the same level as competitive or substituted materials. In this study, we made comparative evaluations between waste molten slags and competitive materials, using 20 samples in total. It was proved that release fluxes of metals from molten slags of municipal solid waste were almost at the same level as competitive or substituted materials. However, a larger impact will be caused from some types of slag that contain harmful metals in high concentrations, such as the slag from shredded automobile residues. The results of release flux showed that nearly 80% of the slope of the flux did not fit with the diffusion range. However, the linearity of every flux was extremely high, regardless of the slope.     

Understanding and communicating sustainability: global versus regional perspectives

While there is no single definition of sustainability, most would agree that it implies that a system is to be maintained at a certain level, held within certain limits. Sustainability denies run-away growth, but it also precludes any substantial set backs or cuts. This sustainability path is hard to reconcile with the renewal cycle that can be observed in most living systems developing according to their natural intrinsic mechanisms. Besides, since different human dominated systems are in significantly different states and stages of development, sustaining those states assumes maintaining social disparities in perpetuity. This creates a challenge in communicating the ideas of sustainability in different regions. Systems are parts of hierarchies where systems of higher levels are made of subsystems from lower levels. Renewal in components is an important factor of adaptation and evolution. But then sustainability of a system borrows from sustainability of a supra-system and rests upon lack of sustainability in subsystems. Therefore by sustaining certain systems beyond their renewal cycle, we decrease the sustainability of larger, higher level systems. The only way to resolve this contradiction is to agree that the biosphere as a whole with humans as one of its components is the only system which sustainability we are to seek. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

The governance of private residential land in cities and spatial effects on tree cover

Trees in cities supply ecosystem services, including cooling, storm water quality management, habitat, visual screening and softening of built form. There is an expanding interdisciplinary field encompassing biodiversity, ecosystem services, and stewardship networks in cities. However most of this work focuses on public greenspace. While much work has been done to demonstrate that trees on private land are an important complement to the public urban forest, and to understand the social drivers of such, less is known about the governance of private greenspace in cities. Private land contributes to a significant component of a city’s tree cover, particularly in cities characterised by low-density residential suburbs. It is important to understand the mechanisms that govern private tree cover, given the pace and scale of urbanisation globally. We combined policy and spatial analysis to examine the influence of larger and denser forms of residential development on suburban tree cover and the scope of contemporary governance measures. We interrogated tree cover patterns in the rapidly densifying and consolidating city of Brisbane, Australia, to show that private residential tree cover is explained by dwelling density, housing age, terrain slope, high school education, and household income. Results show significantly (30%) less tree cover in low-density residential suburbs developed since the early 1990s. We develop five governance principles for reversing the decline of urban trees on private residential property that may be transferable to other rapidly developing cities in around the world.     

The Atmosphere can be a Source of Certain Water Soluble Volatile Organic Compounds in Urban Streams

Surface water and air volatile organic compound (VOC) data from 10 U.S. Geological Survey monitoring sites were used to evaluate the potential for direct transport of VOCs from the atmosphere to urban streams. Analytical results of 87 VOC compounds were screened by evaluating the occurrence and detection levels in both water and air, and equilibrium concentrations in water (C_w^s) based on the measured air concentrations. Four compounds (acetone, methyl tertiary butyl ether, toluene, and m‐ & p‐xylene) were detected in more than 20% of water samples, in more than 10% of air samples, and more than 10% of detections in air were greater than long‐term method detection levels (LTMDL) in water. Benzene was detected in more than 20% of water samples and in more than 10% of air samples. Two percent of benzene detections in air were greater than one‐half the LTMDL in water. Six compounds (chloroform, p‐isopropyltoluene, methylene chloride, perchloroethene, 1,1,1‐trichloroethane, and trichloroethene) were detected in more than 20% of water samples and in more than 10% of air samples. Five VOCs, toluene, m‐ & p‐xylene, methyl tert‐butyl ether (MTBE), acetone, and benzene were identified as having sufficiently high concentrations in the atmosphere to be a source to urban streams. MTBE, acetone, and benzene exhibited behavior that was consistent with equilibrium concentrations in the atmosphere.     

完善《环境保护法》的途径探讨

随着我国环境保护形势的发展，环境法制体系的逐步健全，作为环境保护综合性法律的《环境保护法》在某些方面逐渐显现出滞后性。《环境保护法》的修改与完善，学术界已讨论了很长时间。本文主要从政府管理的角度，对《环境保护法〉的进一步完善进行了一些探讨。     

关于《安全生产法》的几点思考

《安全生产法》是我国安全生产领域的第一部基本法,其颁布实施意义深远。本文就《安全生产法》不尽完善的地方,提出了自己的看法,并提出立法建议,旨在今后进一步完善《安全生产法》,以及做好实施《安全生产法》的相关配套和细化的立法工作。     

财产保全法律制度浅探

关于财产保全制度我国民事讼诉法及最高人民法院的司法解释规定的不完善,有些制度应在立法上加以规定,并严格申请财产保全的条件,将司法实践中行之有效的财产保全的做法上升为法律规定,使我国的财产保全制度更加完善、科学。     

略论《大气污染防治法》的重大修改

《大气污染防治法》已正式颁布实施,本文主要从七个方面阐述了该法在重大修改。