Comments on "Ion adsorption components in liquid/solid systems"

Recently, Wu et al. (J Environ Sci 18(2006) 1167-1175) published a paper entitled as above. In the paper, the authors proposed a plotting method for describing adsorption isotherm, where adsorption density (q e) was plotted against the ratio of equilibrium concentration/particle concentration (Ce/W0) rather than (Ce) as traditionally defined. The authors claimed that this plot can eliminate the "particle concentration effect" (i.e., adsorption isotherm declines with increasing particle concentration), which may otherwise be inevasible with traditionally defined adsorption isotherms. We think that their conclusion is conceptually flawed and the plot may cause substantial inconstancy problems in practice.     

排污权交易与我国环境法治进程

排污许可证制度、排污收费制度和排污权交易制度对于环境污染的治理能够发挥出无可替代的作用.作为三种不同性质的治污手段,其运行机制有本质上的区别,也使得其实施的过程以及效用存在质的差别.本文通过对此三种治污手段的比较,意在揭示政府管制与市场调节两种不同的治理机制对我国环境法治进程的影响,并初步探讨了我国环境法治进程的路径选择.     

电-Fenton法预处理青霉素废水的降解规律研究

研究电-Fenton法预处理青霉素钠(penicillin G sodium,PGN)模拟废水的降解规律,分析预处理过程中PGN浓度、COD、TOC的变化情况及BOD5/COD改善情况.当T=20℃、pH=3时,投加0.5g/L FeSO4、0.2 mL/L H2O2,于0.3 A电流下降解浓度为100 mg/L的PGN废水,120 min后PGN去除97.9%,COD去除76.7%,TOC去除59.8%,BOD5/COD由0升至0.4,有效提高了废水的可生化性.以红外光谱(infrared spectrogram,IR)和液相色谱-质谱联用(Liquid chromatogramMass chromatogram,LC-MS)检测青霉素钠的降解产物,说明青霉素钠抑菌的关键结构b-内酰胺环被破坏,抗菌性消失,有助于生物处理有效去除.     

三峡库区生活垃圾总磷的分布特征和溶出规律研究

了解垃圾堆放场堆存生活垃圾的污染物含量及浸泡条件下污染物的溶出规律，有助于正确评价垃圾堆放场所带来的环境影响，从而为政府部门的决策提供依据。文章以三峡库区为例，通过测定三峡库区主要垃圾堆放场堆存生活垃圾总磷的含量，分析它们的分布特征，并且进行生活垃圾浸泡条件下总磷的溶出实验，分析它们的溶出规律，为三峡库区的环境保护提供帮助。结果表明，(1)三峡库区生活垃圾总磷的含量位于50-3290mg／kg之间，总磷分布集中于100-1600mg／kg之间，且区域差异较大；(2)生活垃圾淹没条件下总磷的释放规律为开始较慢，逐渐增大，达到最大值以后减少，最后趋于稳定；(3)生活垃圾淹没条件下总磷的单位溶出量与时间的关系满足逻辑斯特模型w=α／[1 βexp(-kt)]，且垃圾单位可溶出量α随质量增加而减少，利用本模型可以预测垃圾进入水体后总磷溶出的初期行为。     

城市生活垃圾厌氧消化的熵分析

在城市生活垃圾厌氧消化的整个过程中,从熵的角度出发,对其进行分析,得出如下结论:(1)在厌氧消化的前处理系统(收集、分选及底物强化等)中,收集是一个熵增过程,分选是一个熵减过程,而预处理强化则是一个熵减过程(。2)通过以葡萄糖为发酵底物的发酵过程的ΔG的分析可知:在水解产酸阶段,ΔGθ<0,反应自发进行,故该过程的ΔS﹥0,即该过程是一个熵增过程;在产氢产乙酸阶段,ΔS<0,故这是一个熵减过程,但后续反应对氢的利用则可能使该阶段变为一个熵增过程;在产甲烷阶段,ΔGθ<0,反应均自发进行,故该过程的ΔS﹥0,即该过程是一个熵增过程(。3)城市生活垃圾厌氧发酵产物的资源化利用是一个熵增过程(。4)分选、溶胞强化、产氢产乙酸及发酵产物的资源化利用等工序可能成为厌氧消化的限速步骤。     

德国水法发展对我国治水的借鉴意义

本文从深受欧盟水政策影响的德国水治理的历史发展和基础理念出发,对德国《水平衡管理法》的法规框架和总则进行了阐述、分析与比较。德国经验表明,在法治框架下,依可根据持续性原则,对水事进行综合治理。只有根据可持续性原则和通过法治,才能长期确保水安全,维护人与自然的和谐,保持水体清洁和维护生态平衡,确保当代及后代人的环境与发展权。水事综合治理原则不仅要通过协调水体使用与保护之间的关系,来调整环保在相对于经济和社会的传统不平衡地位,更要遵循自然水循环的本质特征。建议我国在《水污染防治法》的修订中,需要基于我国现实技术支撑的易操作制度,来实践可持续性原则和水事综合治理原则,强化法律间的协调。同时,还在立法技术上提出了若干建议。     

Protected-Area Monitoring Dilemmas: a New Tool to Assess Success

Abstract:  Understanding factors that influence the success of protected areas in curbing unsustainable resource consumption is essential for determining best management strategies and allocating limited resources to those projects most likely to succeed. I used a law-enforcement and monitoring game-theory model from the political science literature to identify three key variables useful in predicting the success of a protected area: costs of monitoring for rule breakers, benefits of catching a rule breaker, and probability of catching a rule breaker if monitoring. Although assigning exact values for each of these variables was difficult, the variables had a strong predictive capacity even when coded as coarse ordinal values. A model in which such values were used correctly predicted the outcome of 88 of 116 protected areas sampled from the peer-reviewed literature. The model identified a critical zone of common mismatch between protected-area circumstances and management policies. In situations where the costs of monitoring were greater than the product of the probability of catching a rule breaker and the benefit of doing so, conservation was unlikely to succeed. Control of illegal use of protected resources was reported in only 8% of such cases, regardless of strategies to motivate potential users to cooperate with conservation. My model does not prescribe a best management policy for conserving natural resources; rather, it can be used as a tool to help predict whether a proposed management policy will likely succeed in a given situation.     

Bayesian Decision Analysis for Evaluating Management Options to Promote Recovery of a Depleted Salmon Population

Abstract:  The endangered population of sockeye salmon (Oncorhynchus nerka) in Cultus Lake, British Columbia, Canada, migrates through commercial fishing areas along with other, much more abundant sockeye salmon populations, but it is not feasible to selectively harvest only the latter, abundant populations. This situation creates controversial trade-offs between recovery actions and economic revenue. We conducted a Bayesian decision analysis to evaluate options for recovery of Cultus Lake sockeye salmon. We used a stochastic population model that included 2 sources of uncertainty that are often omitted from such analyses: structural uncertainty in the magnitude of a potential Allee effect and implementation uncertainty (the deviation between targets and actual outcomes of management actions). Numerous state-dependent, time-independent management actions meet recovery objectives. These actions prescribe limitations on commercial harvest rates as a function of abundance of Cultus Lake sockeye salmon. We also quantified how much reduction in economic value of commercial harvests of the more abundant sockeye salmon populations would be expected for a given increase in the probability of recovery of the Cultus population. Such results illustrate how Bayesian decision analysis can rank options for dealing with conservation risks and can help inform trade-off discussions among decision makers and among groups that have competing objectives.     

Hedging Rules for the Operation of Lake Okeechobee in Southern Florida

Lake Okeechobee is the major source of freshwater in Southern Florida. With the increasing possibility of water stress, determining how to manage water during drought periods is essential to the operation of the Lake. This study deals with operational problems related to the management of Lake Okeechobee and the challenges involved in the implementation of hedging policy. We examine the implications of applying a theoretical hedging rule approach, comprising inter‐ and intrayear models, for the management of Lake Okeechobee and explore several optional hedging policies. The results demonstrate that hedging rules could reduce profit loss particularly under serious water stress, and might be applied sooner to mitigate the risk of severe water shortages. We suggested that the management of Lake Okeechobee should consider both short‐ and long‐term hedging nested. It is also demonstrated that the practical applicability of rolling decision making with updated forecast. Based on the results of the model, the merits of explicit optional hedging rules are demonstrated.     

基于随机森林的高速公路运营隧道风险判别法则研究*

为快速、准确识别山区高速公路隧道不同区段风险因素组合,基于交通事故调研数据,分析其时空变化规律;从人-车-路-环境角度系统筛选风险影响因素,采用随机森林理论构建风险等级预测模型;以决策树与规则相互关系为基础,结合自变量重要评分法,提出基于随机森林的高速公路运营隧道风险判别法则。研究结果表明:判别法则集预测精度较好且运行时间短,能够明确高速公路不同隧道区段事故成因,为预防隧道严重交通事故发生提供参考。