五箱一体化活性污泥工艺循环周期设置研究

五箱一体化活性污泥工艺采取交替运行方式,不需要污泥和混合液回流,良好的循环周期设置对系统至关重要,通过试验研究对不同循环周期设置时的处理效果进行了比较,对主体段进水池状态进行了跟踪试验,结果表明,在水力停留时间和泥龄分别为13 h、18 d的条件下,主体段按120 min设置时能形成良好的厌氧释磷条件,磷的释放率达到0.88 gP/kg MLSS·h,主体段、过渡段和沉淀段分别按120、60和60 min的周期设置时TP、TN的去除率达到90%以上.     

Intergenerational equity and discounting

A standard framework is presented as an underlying model for the discounting debate. Views and proposals for the techniques and rates of discounting are assessed. Alternative modeling frameworks for studying intergenerational equity issues are evaluated with the result that the basic insights they provide do not differ very much. Results from model experiments involving different discount rate proposals show that fudging the discount rate does not lead to efficient climate policy. Three major clusters of opinions are identified regarding the applicability of cost-benefit analysis to the climate change problem and the appropriate discount rate to use. It is concluded that under some very special circumstances the cost-benefit rule should be abandoned and cost-effective strategies implying standard discount rates should be sought to reach clearly defined and justified environmental targets. This revised version was published online in July 2006 with corrections to the Cover Date.     

Surfer软件和AutoCAD在污染场地调查及风险评估中的应用

在场地调查和风险评估报告中需要描述污染物分布和确定土壤修复区域和范围,目前对此无统一的技术要求,不同案例使用的技术方法不同。今提出将 Surfer软件和 AutoCAD结合使用生成等值线图件,以及据此确定污染土壤修复范围的方法,并基于某搬迁化工厂初步土壤调查及风险评估的案例介绍了操作步骤。旨在介绍2个专业软件联用的新功能的开发和使用技巧,为编制场地调查和风险评估报告提供一种便捷、易操作的工作方法。     

Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes

Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.     

Climate Impact Response Functions for Terrestrial Ecosystems

We introduce climate impact response functions as a means for summarizing and visualizing the responses of climate-sensitive sectors to changes in fundamental drivers of global climate change. In an inverse application, they allow the translation of thresholds for climate change impacts (‘impact guard-rails’) into constraints for climate and atmospheric composition parameters (‘climate windows’). It thus becomes feasible to specify long-term objectives for climate protection with respect to the impacts of climate change instead of crude proxy variables, like the change in global mean temperature. We apply the method to assess impacts on terrestrial ecosystems, using the threat to protected areas as the central impact indicator. Future climate states are characterized by geographically and seasonally explicit climate change patterns for temperature, precipitation and cloud cover, and by their atmospheric CO₂ concentration. The patterns are based on the results of coupled general circulation models. We study the sensitivity of the impact indicators and the corresponding climate windows to the spatial coverage of the analysis and to different climate change projections. This enables us to identify the most sensitive biomes and regions, and to determine those factors which significantly influence the results of the impact assessment. Based on the analysis, we conclude that climate impact response functions are a valuable means for the representation of climate change impacts across a wide range of plausible futures. They are particularly useful in integrated assessment models of climate change based on optimizing or inverse approaches where the on-line simulation of climate impacts by sophisticated impact models is infeasible due to their high computational demand. This revised version was published online in July 2006 with corrections to the Cover Date.     

三论灾害防御能力的基本定义与特征

综合灾害防御能力评估已成为应急管理业务和研究的重要内容之一.在前期研究基础上,首先从近年来灾害系统的复杂性特征和应急管理的需求角度出发,对综合灾害防御能力进行了再理解,然后对现有灾害防御能力的多属性综合评估方法进行了梳理总结.以气象灾害为例,通过68项指标构建了我国综合气象灾害防御能力的6个单项指标体系,即制度适应能力...     

微污染原水处理的吸附和沉淀以及预涂过滤一体化技术

集成膨润土吸附与硅藻土预涂膜过滤技术为一体处理微污染源水,同时在内部引入沉淀单元,在单一设备中实现了膨润土吸附、沉淀、过滤三位一体的目的.研究结果表明,吸附-沉淀-分离一体化技术有效地延缓了硅藻土预涂膜过滤时水头损失的上升速度,和原有的吸附预涂膜分离一体化技术相比,有效延长了运行周期,同时,微污染源水有机污染物的去除效果得到显著提高,表明该技术对于微污染源水的处理具有良好的应用前景.     

大气扩散模式预测计算软件的开发

结合Microsoft Visual Basic(VB)语言的编程特点,探讨了大气环境影响评价计算机软件系统的理论基础、设计思想和应用程序编制的实现方法,编制了专门处理大气扩散模式浓度计算的应用程序,避免了大量繁杂的手工计算工作,使计算快速、准确,提高了环境影响评价工作的质量.     

Fenton试剂预处理化工综合废水的研究

以化学工业园区废水为研究对象初步研究了Fenton试剂预处理化工综合废水时各影响因子的作用机制,通过正交实验确定了Fenton反应的最佳操作条件为：反应时间70 min,硫酸亚铁投加量为2.6 mmol/L,温度为40℃,初始pH3.5,二价铁离子和过氧化氢的摩尔比为1∶8时,COD的去除率可达到60%以上,B/C值可...     

河流水质评价中模糊数学评价法的应用与比较

选择2005年6个典型日（1月12日、3月10目、5月10日、7月13日、9月8日和11月10日）的水质,运用两种模糊数学评价法对浙江西苕溪流域港口断面的水质进行评价并作比较。第一种数学评价法采用较为简单的单因素模糊综合评价法,另一种采用多级模糊数学评价法。评价结果表明,1月12日、3月10日和11月10日的水质达到国家Ⅰ类水质标准;而5月10目的水质相对最差。比较两种评价方法,单因素模糊综合评价法对单个因素的影响敏感,特别是超标值对最后的相对隶属度贡献大;而多级模糊评价法综合各个因素来评价现状水质,因而反映出水质的综合情况。结合港口断面的特点分析水质变差的原因,结论是：流域农业劳作带来的面源污染物质进入港口断面使得该断面在农作高峰期水质较差;同时,断面的水资源短缺问题较为严重,导致水环境容量较小,污染物较难稀释扩散。