基于物质平衡模型的工业汞污染防治环境经济手段分析

我国以行政命令手段为主的环境管理措施并不能完全有效控制环境汞污染,因而有必要引入环境经济手段。本文基于汞在采掘、冶炼和产品生产三个生产环节中的利用、处置与排放特征,构建了经济系统及行业部门的汞物质平衡模型,并发现,单个污染源的汞污染物治理难以保证消除汞的环境危害。因而,采取环境经济手段控制工业汞污染,尽可能少的向环境中排放汞,在涉汞工业系统的层面上提高汞的利用效率和再资源化率。我国工业汞污染防治的环境经济手段包括环境污染价格、税费以及绿色金融两大类,但仅对生产环节高浓度汞排放发挥作用,对于堆存、再提取和处置环节的汞排放则作用不大。对此,应从扩大环境税(排污费)的征收范围,建立长效的绿色金融机制和推进第三方治理低含量含汞废物,这三个方面加以改进。     

污染物总量减排中的问题和对策

“十一五”全国主要污染物排放总量减少10％已成为约束性指标。面对严峻的形势，尽管社会各界空前重视，但各地减排工作进展不平衡，仍存在经济增长方式粗放、政策措施落实不到位等问题。针对存在的问题，提出了加大产业结构调整力度、污染防治资金投入、实施严格的环境准入制度等政策措施。完善减排体系、适时修改国家污染减排核算细则等技术措施，加大环境执法和环境监管力度、减排宣传力度等保障措施。     

Thermal risk analysis of cumene hydroperoxide in the presence of alkaline catalysts

Many studies have been performed to clarify the basic thermal runaway hazards and kinetics of cumene hydroperoxide (CHP) decomposition. However, materials that are incompatible with CHP have not been clearly identified. Alkaline solutions have been used as a catalyst to form dimethylphenyl carbinol (DMPC) and dicumyl peroxide (DCPO); however, these solutions also affect the reaction and storage temperature of CHP. In this study, thermal calorimeters, differential scanning calorimetry (DSC) and vent sizing package 2 (VSP2), were used to compare the effects of various bases on the decomposition of CHP in cumene. Specifically, the exothermic onset temperature, change in pressure over time, self-heating rate and heat of decomposition were evaluated. Moreover, to appraise the degree of hazard associated with the use of CHP, the compatibility of CHP with various substances was analyzed, and a risk matrix for thermal runaway reactions was obtained. The results of the present study could be used to design safety procedures for the production of CHP and its derivatives.     

On spurious water flow during numerical simulation of steam injection into water-saturated soil

Numerical simulation of steam injection into a water-saturated porous medium may be hindered by unphysical behavior causing the model to slow down. We show how spurious water flow may arise on the boundary between a steam zone and a saturated zone, giving rise to dramatic pressure drops. This is caused by the discretization of the temperature gradient coupled with the direct relation between pressure and temperature in the steam zone. The problem may be a severe limitation to numerical modeling. A solution is presented where the spurious water flow is blocked and this widely enhances the performance of the model. This new method is applied to a previously reported example exhibiting numerical problems. Furthermore, it is applied to the simulation of 2-D sandbox experiments where LNAPL is remediated from a smearing zone by steam injection. These experiments would have been difficult to analyze numerically without the adjustment to prevent spurious flow.     

提高大学英语听力之浅见

针对大学生听力存在问题进行分析，从师生教与学两个角度提出了相应的对策，选择适合学生水平的听力资料，激发听力兴趣，树立听力信心，进行多途径的听力训练，养成良好的听力和英语思维习惯，增强语言运用的频率等，以期达到语言学习的目的。     

半轴套管内腔折叠产生原因及预防措施

分析了半轴套管成形过程中出现折叠的特点和形成原因 ,并根据折叠形成原因提出了相应的预防措施 ,从而解决了生产过程中存在的质量问题。     

Socially cooperative choices: An approach to achieving resource sustainability in the coastal zone

Achieving resource sustainability, particularly in the coastal zone, is complicated by a variety of interdependencies and trade-offs between economic, social, and ecological variables. Although trade-offs between each of these variables are important, this paper emphasizes the social components of resource management. In this regard a distinction is made between individual and cooperative choices. Individual choices frequently are made from a shortterm, self-interested perspective, whereas cooperative choices are made from a long-term, community and resource-sustainability perspective. Typically, when presented with a spectrum of resource management decisions, individuals have a tendency to act in a self-interested manner. Thus, cooperative benefits, such as reduced conflict and improved resource certainty, are not realized. An overview of selected aspects of social dilemma theory suggests that socially cooperative choice outcomes are attainable in coastal zone management by integrating structural and behavioral solutions in resource use decision making. Three barriers to successful integration of structural and behavioral solutions are identified as self-interest, mistrust, and variable perceptions of resource amenities. Examples from coastal zone management indicate that these barriers may be overcome using approaches such as scopereduction, co-management, community education, and local participation. The paper also provides comment on the potential benefits of integrating structural and behavioral solutions in international coastal zone management efforts.     

Jute bioblanket as a soil rehabilitation strategy in Sorocaba,Brazil: Soil chemistry and SWOT approaches

Soil erosion and the invasion of exotic plant species are major constraints to achieve sustainable development around the world. Currently, we find few products devoted concomitantly to combatting soil erosion as well as the establishment of unwanted exotic plants. In this paper, we introduce a new product, called herein a bioblanket, that protects the soil and impedes the establishment of exotic plant species. This product is of simple design, and to manufacture it, we use two biodegradable materials: jute tissue and grass wastes. We designed this product to combat soil erosion and the germination and establishment of new, unwanted, invasive plant species. In this paper, we describe our evaluation of how successful this product was in terms of improving the chemical attributes of soil. We also identified the product's potentialities and weaknesses by means of strengths, weaknesses, opportunities, and threats (SWOT) analysis. The bioblanket ameliorated the chemical attributes of the soil, as evidenced especially by the neutralization of acidity (8.5%) and aluminum toxicity (33%), and by an increment in nutrients concentration. We argue that after adequate treatment and management, the residues of plants that are normally considered unwanted materials can be transformed into a raw material to control the propagation of unwanted plant species, and concomitantly control soil erosion while improving the chemical conditions of the soil. The improvement of the soil chemical attributes was one of the main positive effects reported through the SWOT analysis. In addition, the SWOT analysis revealed some features that need improvement in future generations of the product, but we argue that these features do not impede the benefits for the use of the product in its present form.     

添加液促进电动法修复苯酚污染土壤的模拟研究

模拟研究结果表明,电动技术能有效地修复被苯酚污染的砂土。在电场强度为2V／cm的情况下,苯酚在污染砂土中向阳极迁移,富集发生在距离阳极8cm处。在阴极槽添加的LAs浓度为0．046mol·L^-1时,苯酚在砂土中迁移的富集浓度可以达到未添加LAS时的2．43倍。向阳极槽添加0．1mol·L^-1 NaOH溶液与向阴极槽添加0．1mol·L^-1柠檬酸溶液都有利于苯酚的富集,且向阳极槽添加NaOH溶液更有利于苯酚的富集。     

Transfer rate of pesticide residues from medicinal plants in different types of extractive solutions

Abstract

Starting from the suspicion that the medicinal herbs may contain traces of pesticides and taking into account the risks of patients being exposed to contaminated products, the aim of this research was to evaluate the pesticide residues and the degree of their transfer (%) in three types of preparations (infusion, decoctionand cold maceration), for four medicinal plant species very often used in phytotherapy (Rosmarini folium, Menthae folium, Saturejae herba and Basilica herba). For each type of plant product, four samples were purchased from different manufacturers and they have been analyzed using gas chromatography- tandem mass spectrometry. One out of four samples of the same plant species contain at least one pesticide residue above the maximum level and shows a significant transfer of these residues in aqueous extractive solutions during extraction. The highest rate of pesticide transfer from medicinal plants was identified in infusions, recommended by many manufacturers.