基于选择实验法的支付意愿研究——以湘江水污染治理为例

论述了选择实验法的理论基础,运用该方法对湘江水污染治理中居民的支付意愿进行了实证分析,以此推断实施湘江流域水污染治理工程后湘江流域水质好转带来的环境价值。选择在湘江流域的八大城市布点,获取了587份居民的调查问卷数据资料。通过计量经济学分析,得到如果实施湘江流域水污染治理工程、彻底解决湘江重金属污染问题,水质完全达到或优于Ⅱ类水标准,湘江流域居民总的支付意愿为1074亿元。     

城市生活垃圾中纤维素含量测定方法优化

对传统硫酸法进行改进,建立适用于城市生活垃圾纤维素含量的测定方法。以脂肪抽提时间、硫酸浓度、水解反应温度、水解反应时间、稀释硫酸浓度、回流时间为考察因素进行6因素5水平正交实验。结果表明,测定纤维素含量的最佳条件为：脂肪抽提时间4h、硫酸浓度70％、水解反应温度30℃、水解反应时间5h、稀释硫酸浓度5％、回流时间3h。优化后纤维素测定条件RSD均小于1．69％,平均回收率98．76％,表明该方法的精度高,可靠行强。     

长期施肥对水稻土耕层微生物生物量氮和有机氮组分的影响

以亚热带2个国家级稻田土壤肥力变化长期定位监测点的土样为对象,研究了长期施肥对土壤微生物生物量氮(B_N)和有机氮组分的影响.采用氯仿熏蒸-K₂SO₄提取法和酸水解-蒸馏法分别对耕层土壤微生物生物量氮和有机氮组分进行了测定.结果表明,经过17a的有机无机肥配合施用,土壤氮含量水平较低的宁乡点,土壤全氮平均每年增加约40 　mg·kg^－1,而土壤氮含量水平较高的南县点,平均每年增加约55 　mg·kg^－1.有机无机肥长期配合施用也提高了土壤微生物生物量氮和微生物生物量氮占全氮的比例;同时也显著增加酸解性氮及氨基酸态氮、酸解未知氮的含量.此外,土壤酸解性氮及其组分均与微生物生物量氮存在极显著的正相关关系,其中氨基酸态氮和酸解未知氮对微生物生物量氮的影响最大.研究表明,有机无机肥配施是使稻田土壤氮素含量提高的重要措施,有机无机肥配施促进了土壤氮库的积累,即易矿化和较难矿化2部分氮库同时增加.     

Transport of bacterial cell (E. coli) from different recharge water resources in porous media during simulated artificial groundwater recharge

• The recharge pond dwelling process induced changes in cell properties. • Cell properties and solution chemistry exerted confounding effect on cell transport. • E. coli cells within different recharge water displayed different spreading risks. Commonly used recharge water resources for artificial groundwater recharge (AGR) such as secondary effluent (SE), river water and rainfall, are all oligotrophic, with low ionic strengths and different cationic compositions. The dwelling process in recharge pond imposed physiologic stress on Escherichia coli (E. coli) cells, in all three types of investigated recharge water resources and the cultivation of E. coli under varying recharge water conditions, induced changes in cell properties. During adaptation to the recharge water environment, the zeta potential of cells became more negative, the hydrodynamic diameters, extracellular polymeric substances content and surface hydrophobicity decreased, while the cellular outer membrane protein profiles became more diverse. The mobility of cells altered in accordance with changes in these cell properties. The E. coli cells in rainfall recharge water displayed the highest mobility (least retention), followed by cells in river water and finally SE cells, which had the lowest mobility. Simulated column experiments and quantitative modeling confirmed that the cellular properties, driven by the physiologic state of cells in different recharge water matrices and the solution chemistry, exerted synergistic effects on cell transport behavior. The findings of this study contribute to an improved understanding of E. coli transport in actual AGR scenarios and prediction of spreading risk in different recharge water sources.     

Integrating Modeling and Field Experiments to Evaluate Impacts of Vegetative Practices on Ponderosa Pine Watersheds1

Abstract: Determining watershed response to vegetation treatment has been the subject of numerous hydrologic studies over the years. However, generalizing the information obtained from traditional paired‐watershed studies to other watersheds in a region is problematic because of the empirical nature of such studies and the context dependence of hydrologic responses. This paper addresses the issue of generalizing hydrologic information through integration of process‐based modeling and field observations from small‐scale watershed experiments. To this end, the results from application of a process‐based model were compared with the results from small‐scale watershed experiments in ponderosa pine forests of Arizona. The model simulated treatment impacts reasonably well when compared to the traditional paired‐watershed approach. However, the model tended to overestimate water yields during periods of low flow, and there was a significant difference between the two approaches in the estimation of treatment impacts during the first four years following treatment. The results indicate that the lumped‐parameter modeling approach used here may be limited in its ability to detect small changes, and tends to overestimate changes that occur immediately following treatment. It is concluded that watershed experiments can be highly informative due to their direct examination of cause‐effect relationships, while process‐based models are useful for their processing power and focus on functional relationships. The integrated use of both watershed experiments and process‐based models provides a way to generalize hydrologic information, illuminate the processes behind landscape treatment effects, and to generate and test hypotheses.     

Lysimeter Soil Retriever (LSR)—An Application of a New Technique for Retrieving Soils from Lysimeters

In Europe more than 2,500 lysimeters operated by research institutes and industry (Lanthaler 2005). Originally lysimeters were built for investigations of soil water and solutes, nutrient leaching and pesticide degradation (see e.g. Winton and Weber 1996). Currently lysimeters additionally used as a tool for investigations on biological processes, and structural changes of plants, including root distribution, and enzyme activities etc. (see e.g. Dizer et al. 2002; Schloter et al. 2005).     

臭氧氧化地下水石油污染物的动态模拟试验

针对被石油类污染物严重污染的淄博市水源地下水进行了Ｏ３净化技术的动态试验研究,建立了一套模拟地下水运动的室内装置。通过在模拟装置中的动态Ｏ３化反应表明：Ｌ３对含水层油污染的处理是有效的;在污染物肖度１－５ｍｇ／Ｌ和Ｏ３投加量４５ｍｇ／Ｌ,水层表面浮油去除率达９０％。     

Estimating the economic value of improvements in river ecology using choice experiments: an application to the water framework directive

The Water Framework Directive is a major regulatory reform of water resources management within the European Union. Integrated catchment management plans must be prepared for all river basins, in order to achieve 'good ecological status' in all EU waters. Ecological status is a broader measure of water quality than the chemical and biological measures that were previously dominant. The Directive calls for a consideration of the economic costs and benefits of improvements to ecological status. In this paper, we use the choice experiment method to estimate the value of improvements in three components of ecological status. Given the high resource cost of valuation studies, benefits transfer methods will be needed in implementing the Directive. We thus also test the ability of choice experiments for benefits transfer across two very similar rivers in the UK.     

模拟实验研究煤矿酸性水中Co、Ni、Zn、Cd、Al、Cr、As、Pb可溶性金属迁移行为

通过模拟煤矿酸性水环境,对来自2个不同产地的煤系非均质黄铁矿样品进行了不同固液比的淋滤实验,对反应体系物理化学状态以及其中的Co、Ni、Zn、Cd、Al、Cr、As、Pb8种元素的释放行为进行了长达312h跟踪检测和对比.结果显示,在2种不同来源的煤系黄铁矿样品反应体系中,Co、Ni、Zn、Cd的释放行为均为持续升高,说明这些元素的释放受体系中物理化学状态的影响相对较小,在液相中具有较高的迁移行为;Al、Cr、As、Pb在不同样品体系中的释放行为差异较大,受到体系pH值、吸附及共沉淀作用等因素的影响,是相对不易迁移的元素.煤矿酸性水环境中元素释放和迁移行为主要受到黄铁矿的氧化还原反应速率、反应体系介质pH值和围岩矿物学性质3个宏观因素控制.     

蒙德法与道化法的选取

运用蒙德法和道化法 ,对煤气发生系统评价单元进行安全评价 ,指出两者在进行火灾、爆炸的危险评价时 ,其结论基本上是接近的 ,但仍保持着各自的特点。在此基础上 ,笔者提出 :当评价单元要求在火灾、爆炸、毒性危险因素有更全面的反映时 ,宜采用蒙德法 ;对影响范围、损失情况有具体反映和进行项目预评价时 ,可采用道化法的建议。