关于环境空气质量和谐度的研究与应用

在目前我国城市都在应用空气污染指数来评价空气质量的基础上,提出应用环境空气质量和谐度来评价大、中型城市环境空气质量,详细阐述了环境空气质量和谐度的定义、评价依据、级别划分、评价方法以及定性描述,并对环境空气质量和谐度对城市环境空气质量评价进行了应用。     

环境影响评价中容易忽视的问题及处理方法

在环境影响评价过程中,经常会遇到一些简单却又很容易被忽视的问题,如水环境评价中的pH值、DO、大气环境影响预测中的取样时间等。如若处理不当将直接影响到环评报告书评价结论,只有掌握这些问题的处理方法,才能不断提高环评人员的业务水平和评价报告的质量。     

Quantifying energy use, carbon dioxide emission, and other environmental loads from island tourism based on a life cycle assessment approach

The main purpose of industrial ecology is to evaluate and minimize impacts from economic activities of human society. Tourism as one economic activity, results in a full range of environmental impacts, but few applications of industrial ecology to tourism management have previously been discussed. Life cycle assessment (LCA) is used in this research to explore environmental impacts of island tourism, and then the environmental loads per tourist per trip can be found. Penghu Island in Taiwan is taken as an example to examine this new approach. Various environmental loads in transportation, accommodation, and recreation activity sector are all inventoried and calculated here. In summary, per tourist per trip uses 1606 MJ of energy, 607 L of water, and emits 109,034 g of CO₂, 2660 g of CO, 597 g of HC, 70 g of NO_x. In addition, per tourist per trip also discharges 416 L of wastewater, 83.1 g of BOD, and 1.95 g of solid waste. In terms of energy use, the transportation consumes the largest energy (67%); in particular, the airplane sector. Moreover, per Penghu tourist results in more environmental loads than local people; for example, the amount of solid waste discharge per tourist is 1.95 kg per day, while that of per local people is 1.18 kg. Finally, the advantages and limitations of such LCA approach are also discussed.     

南京市土地利用遥感监测与评价

以2006年和2007年TM遥感影像为数据源,利用GIS技术,对南京市的土地利用动态变化进行了监测,结果表明,从2006～2007年,南京市耕地减少6723.72hm2,林地减少975.46hm2,而水域增加了1663.26hm2,建设用地增加了5191.11hm2,草地增加758.78hm2,未利用地增加了86.03hm2。与2006年相比南京市生态环境质量指数略有下降。     

基于熵权法的连云港市入海河流环境健康评价——以蔷薇河为例

建立包含压力-状态-响应要素的指标体系,采用基于熵权的模糊数学评价方法,运用相对隶属度算法评价在快速城市化胁迫下(2000～2007年)连云港市入海河流(以蔷薇河为例)相对健康程度,该方法避免了主观判断河流环境健康标准的不确定性.评价结果表明2000～2007年,连云港市蔷薇河相对健康整体大致呈下降趋势,最优年为200...     

基于饮用水健康风险评价的江苏省产业结构调整对策研究

将产业结构调整与饮用水健康风险评价结合起来,从宏观角度提出对策分析,有利于整体水环境(包括饮用水源地)的改善.基于长江流域、太湖流域和淮河流域饮用水源地2007～2009年水质监测数据,应用美国环境保护署( U.S.EPA)推荐的健康风险模型计算、分析、评价了江苏省3大流域的水环境健康风险.研究结论揭示了3大流域饮用水...     

荒漠能源植物气化发电的环境影响评价

对荒漠生物质气化发电进行LCA评价,建立评价模型,在评价过程中选用了燃煤发电系统为参照.研究结果表明,生物质利用过程没有CO2的排放,整个发电周期中仅原料的生产、运输以及预处理过程消耗能量导致CO2排放,因此生物质气化发电方案的排放量远远小于燃煤方案,减排量达到了87%-94%.生物质发电与燃煤发电相比,对环境污染降低程度的总指数为3.68.生物质能源的开发大大削减了化石能源利用带来的环境污染问题,同时也能够缓解能源危机.     

Analysis of risk trade-off relationships between organic solvents and aqueous agents: case study of metal cleaning processes

When substance substitution is implemented to reduce the target risk of production processes, countervailing risks may occur. The goal of this study is to analyze the risk trade-off relationships between organic solvents and aqueous agents in the case study of metal cleaning processes. Global environmental impacts and local risks were evaluated for the eight scenarios by life cycle and risk assessments, respectively. The results show that the contribution of the processes using chlorinated solvents to photochemical ozone creation, human toxicity, ozone depletion, and ecotoxicity was larger than processes using aqueous detergents, while the contribution of aqueous processes to eutrophication was larger than chlorinated processes. Neighbors’ health risk around a cleaning site using chlorinated solvents was sufficiently small in all scenarios, whereas ecological risk due to surfactants which are contained in aqueous detergents and emitted to the local aquatic environment should be reduced. Cleansing agents and process facilities should be selected on the basis of the comprehensive analysis of risk trade-off relationships for feasible and cleaner production.     

Approach and application of life cycle screening in early phases of process design: case study of supercritical water gasification

Process design can be influenced most in the early phases. Here, screening methods play a major role, as they reduce the complexity of a system studied by making a pre-selection from a set of alternatives available. The remaining alternatives can be analyzed in more detail in the subsequent design process, which increases design efficiency. The present paper focuses on a multi-stage screening approach for use in the early process development phase in particular. This approach is based on the use of non-compensatory decision support methods that are transferred to life cycle assessment. It may be divided into a first stage, in which the decision matrix used is developed on the basis of decision analysis principles, and a second stage, in which the decision matrix developed is further processed using non-compensatory decision support methods. An example of such a method is the pareto-dominance analysis applied here. The approach proposed is validated by application to the process of biomass gasification in supercritical water, which is being developed at the moment. Here, screening is performed to identify those life cycles, the potential environmental impacts of which contribute most to the total impacts. Attributes are selected in line with the requirement of a simple, but still sufficient modeling of these environmental impacts. By pareto-dominance analysis, emissions from the gasification of sewage sludge, the pre-chain of natural gas production, and from the construction of the supercritical gasification plant are identified to dominate over the remaining life cycles studied. Apart from the predominating alternatives, it is of particular importance to know the dominated alternatives. Due to their small shares in the result, no or only a small expenditure is needed to identify improvement potentials of these alternatives.     

Life cycle assessment of milk produced in two smallholder dairy systems in the highlands and the coast of Peru

Life Cycle Assessment (LCA) was applied to two smallholder milk production systems in Peru in order to evaluate the environmental burden of milk produced in each. An Andean highland milk production system where livestock feeding is restricted to permanent pastures supplemented with on farm grown ryegrass-clover was opposed to a coastal system with dairy cows fed a diet consisting of fodder maize and purchased concentrate. Milk production levels (kg/cow day) differed considerably with 2.57 for the highland and 19.54 for the coastal system. A Life Cycle Inventory was calculated for the functional unit of 1 kg energy corrected milk (ECM) and the environmental impacts global warming, acidification and eutrophication were estimated for 1 kg ECM, 1 ha and 1 animal, considering the multi-functionality of the system. The highland system was characterized by a high land use (23.1 m²a/kg ECM vs. 1.71 m²a/kg ECM at the coast). Irrigation water and energy were on the other hand used to a much higher amount at the coast (7291 l/kg ECM and 8791 MJ/kg ECM, respectively) than in the highlands (848 l/kg ECM and 0.20 MJ/kg ECM). Global warming potential, acidification and eutrophication were higher for 1 kg ECM produced in the highlands than at the coast by 10.6 kg CO₂ equivalents, 6.58 g sulfur dioxide equivalents and 10.63 g phosphate equivalents, respectively. Nevertheless, 5220 kg CO₂ equivalents more were emitted per animal at the coast than in the highlands. Also acidification and eutrophication were estimated to be on average 6 and 4 times higher at the coast compared to the highlands when expressed for the functional units of 1 ha and 1 animal.

Results

Whereas livestock is mainly responsible for impacts on the environment in the highlands, at the coast both livestock related emissions and forage cultivation play an important role. Furthermore CO₂ releases from soybean cultivations heavily contribute to total emissions. Sensitivity analysis indicates that for dairy systems relying on crop by-products as feed the choice of the allocation method is a crucial point in a LCA study. Based on the results of this study, strategies in order to reduce the environmental burden of milk production should focus on an increase of production levels and a reduction of methane emissions from enteric fermentation in the highlands and a modification of the concentrate components replacing soya as the protein source at the coast.