污染场地土壤通用评估基准建立的理论和常用模型

污染场地土壤通用评估基准的建立与每个国家的经济水准及社会发展紧密相关.从国际相关领域的发展趋势来看,场地基准的建立基于风险基础之上.我国正在颁布污染场地风险评估技术导则(C-RAG),表明我国已选择风险基础上的污染场地管理模式.文章回顾了污染场地土壤通用评估基准建立的理论、方法及通用模型,并推荐污染场地评估的模型框架,...     

Economical assessment of the design,construction and operation of open-bed biofilters for waste gas treatment

A protocol was developed with the purpose of assessing the main costs implied in the set-up, operation and maintenance of a waste gas-treating conventional biofilter. The main operating parameters considered in the protocol were the empty bed residence time and the gas flow rate. A wide variety of investment and operating costs were considered. In order to check its reliability, the protocol was applied to a number of scenarios, with biofilter volumes ranging from 8.3 to 4000 m³. Results show that total annualized costs were between 20?000 and 220?000 €/year and directly dependent, among other factors, on the size of the system. Total investment and operating costs for average-size compost biofilters were around 60?000 € and 20?000 €/year, respectively, which are concordant with actual costs. Also, a sensitivity analysis was performed in order to assess the relative influence of a series of selected costs. Results prove that operating costs are those that influence the total annual costs to a higher extent. Also, packing material replacement costs contribute significantly to the total yearly costs in biofilters with a volume higher than 800 m³. Among operating costs, the electricity consumption is the main influencing factor in biofilters with a gas flow rate above 50?000 m³/h, while labor costs are critical at lower gas flow rates. In addition, the use of a variety of packing materials commonly employed in biofiltration was assessed. According to the results obtained, special attention should be paid to the packing material selected, as it is the main parameter influencing the medium replacement costs, and one of the main factors affecting investment costs.     

Critical Sampling Points Methodology: Case Studies of Geographically Diverse Watersheds

Only with a properly designed water quality monitoring network can data be collected that can lead to accurate information extraction. One of the main components of water quality monitoring network design is the allocation of sampling locations. For this purpose, a design methodology, called critical sampling points (CSP), has been developed for the determination of the critical sampling locations in small, rural watersheds with regard to total phosphorus (TP) load pollution. It considers hydrologic, topographic, soil, vegetative, and land use factors. The objective of the monitoring network design in this methodology is to identify the stream locations which receive the greatest TP loads from the upstream portions of a watershed. The CSP methodology has been translated into a model, called water quality monitoring station analysis (WQMSA), which integrates a geographic information system (GIS) for the handling of the spatial aspect of the data, a hydrologic/water quality simulation model for TP load estimation, and fuzzy logic for improved input data representation. In addition, the methodology was purposely designed to be useful in diverse rural watersheds, independent of geographic location. Three watershed case studies in Pennsylvania, Amazonian Ecuador, and central Chile were examined. Each case study offered a different degree of data availability. It was demonstrated that the developed methodology could be successfully used in all three case studies. The case studies suggest that the CSP methodology, in form of the WQMSA model, has potential in applications world-wide.     

Evaluating sustainable forest management strategies with the Analytic Network Process in a Pressure-State-Response framework

Nowadays forestry faces a complex management situation; the understanding of sustainable forest management (SFM) has gone far beyond the original meaning of sustainable yield of timber. SFM strategies should fulfil ecological, economic and social functions without causing damage to other ecosystems. In this understanding, forest management actions cannot be seen as isolated or mono-causal. In this case study, indicators for SFM are arranged in a Pressure-State-Response (PSR) framework at forest management unit level. This framework links pressures on the environment caused by human activities with changes of environmental state (condition) parameters. Forest management also responds to these changes by instituting environmental and economic measures to reduce pressures and restore natural resources. The Analytic Network Process (ANP) is utilized to evaluate the performance of four management strategies with regard to the PSR framework on SFM. Priorities of indicators and alternatives are modelled with the ANP resulting from the interconnections to other indicators and their respective cumulative importance. The approach allows for more detailed information on the network of human influences and their impacts on forest ecosystems and goes beyond the limitations of flat-dimensioned indicator sets.     

基于故障树的生物质气化中毒事故BN-LOPA分析

为降低生物质气化中毒事故的概率,本文提出基于故障树的贝叶斯—保护层复合分析法(BN-LOPA),对生物质气化中毒事故进行风险分析。以辽宁省某气化站为例,通过贝叶斯网络计算出该气化站中毒事故发生概率为1.11×10^-4,基于贝叶斯网络推导出中毒事故基本事件的后验概率,得到导致事故发生的故障节点,并对其设置独立防护层,经推导计算,该气化站的气化中毒事故发生概率可降低至5.35×10^-6,风险等级从7级降至5级。结果表明:该气化站增加独立防护层后,符合安全生产的要求。