成都市臭氧重污染成因与来源解析

采用来源解析的方法对2020年成都市发生的一次较为严重的臭氧污染事件进行了研究.结果表明,此次污染过程呈现从清洁-污染-清洁的变化趋势,污染持续时间长达9d,最大臭氧小时浓度达到258.8μg/m3.气象因素在成都臭氧污染中的影响不可忽略,其中温度与臭氧浓度呈现显著正相关关系,东北风主要出现在污染前和污染后,可能起到稀...     

基于生态效益的武汉城市圈土地利用结构优化

满足生态安全的土地利用结构优化是协调社会经济发展与生态环境间矛盾、实现土地持续利用的有效途径。以武汉城市圈为研究区,基于2002～2009年土地利用变更调查汇总数据,引入土壤有机碳储量和土地利用绿当量两个生态指标,评价了城市圈发展不同阶段土地利用结构的生态效益;并通过TOPSIS模型对历年土地利用结构生态合理度进行了评价。在此基础上,以经济效益和生态效益的最大化为目标,构建了2020年多目标优化模型,获得了符合城市圈发展需求的土地利用结构优化方案,呈现“四增三减三稳定”的数量格局,且生态效益指标和生态合理度均呈正向的发展趋势;进而提出了土地资源可持续利用的建议。研究结果对武汉城市圈土地利用总体规划修编、土地利用调控方案的优化以及土地可持续利用具有重要指导意义     

基于安全格局理论的国土空间规划冲突协调途径

为解决国土空间面临的城市蔓延、乡村空心化、环境退化等系统性问题,国土空间规划需要整合出于各部门利益最大化制定的、时常是相互冲突的规划方案,实现“多规合一”。基于安全格局理论提出协调规划冲突的途径,包括：（1）在认识层面,将国土空间规划视为理性过程,利用最小—最大约束途径制定可辩护的规划方案,通过空间博弈协调对有限土地的竞争、寻求各方均可接受的结果;（2）在操作层面,首先识别作为保障自身目标、协调各方利益依据的安全格局,然后据此对空间用途进行谈判。实践中需要建立协调规划冲突的制度机制,并在多方博弈中优先考虑处于劣势的生态和自然资产,通过建立生态安全格局和生态基础设施提供综合生态系统服务,再造秀美河山。     

污水处理系统微生物群落时空分布和构建机制研究进展

探索微生物群落时空分布和构建机制一直是环境微生物生态学研究的目标和挑战。近年来,微生物生态学规律和理论逐渐在工程系统中得到应用,分类群-面积关系、分类群-时间关系和距离-衰减效应等规律已在污水处理系统的微生物群落分布中得到验证。随着研究的发展,微生物时空分布研究已从群落分布规律的发现和描述,拓展到驱动群落分布的因素,即群落构建机制的探索。介绍了污水处理系统微生物群落时空分布规律和构建机制的研究进展,并对未来的方向进行了展望,强调了将生态理论和工程实践相结合的重要性。未来应在污水处理系统核心微生物研究、微生物群落的生物多样性、构建机制与污水处理性能的关联、多组学技术在微生物时空分布和构建机制研究中的应用等方面有所突破。     

遗产区域:一种大尺度文化景观保护的新方法

遗产区域是美国国内针对大尺度文化景观保护的一种较新的方法。该方法重视人与土地之间的互动关系。强调通过对地方历史文化、自然和游憩资源的综合保护与利用。实现遗产保护、经济发展、重建区域身份、提供游憩机会等多重目标。从美国历史保护运动的发展背景出发。回顾了遗产区域的发展历程，从定义、特征与分类三个方面评述了其概念内涵，并对遗产区域保护中的几个关键问题进行了讨论。最后针对遗产区域保护方法在中国的发展与应用提出了相关建议。     

废水排放对近海环境中抗生素抗性基因和微生物群落的影响

污水处理厂是水环境中抗生素抗性基因（ARGs）的重要来源.可移动遗传元件（MGEs）和微生物群落是影响ARGs增殖扩散的关键因素.为探究污水处理厂废水排放对近海环境中ARGs和微生物群落的影响,采用高通量荧光定量PCR （HT-qPCR）和高通量16S rRNA扩增子测序技术,对杭州湾上虞（SY）和嘉兴（JX）两个近岸纳污区（ERAs）及远岸湾区表层沉积物中ARGs、MGEs和微生物群落的组成和分布进行调查.结果表明,多重耐药类ARGs是所有样点中丰度最高的ARGs类型.纳污区沉积物中ARGs和MGEs多样性和丰度远远高于远岸湾区沉积物.JX纳污区沉积物中微生物群落丰富度和多样性高于SY纳污区及远岸湾区沉积物.PCoA结果显示,纳污区与远岸湾区沉积物中ARGs、MGEs和微生物群落分布存在显著的差异,说明长期的废水排放对近海环境中ARGs、MGEs和微生物群落影响较大.ARGs、MGEs和细菌属的共现网络显示,嗜冷杆菌属、假单胞菌属、亚硫酸杆菌属、假交替单胞菌属和芽孢杆菌属等12种菌属与ARGs和MGEs存在显著正相关.多重耐药类和β-内酰胺类ARGs的潜在宿主最多.     

中国城市水务业特许经营法律制度研究简

特许经营作为城市水务业市场化改革的重要实现形式,经历了一个“由盛转衰”的历程。总结其中缘由,现有立法在政府管制体制、政府管制内容、招投标制度和竞争机制的构建方面存在诸多问题。完善城市水务业特许经营法律制度应“双管齐下”,着重从市场准入管制、价格管制和质量管制三方面完善相关制度设计。     

Inexact fuzzy-stochastic mixed-integer programming approach for long-term planning of waste management – Part A: Methodology

In this study, an inexact fuzzy chance-constrained two-stage mixed-integer linear programming (IFCTIP) approach is proposed for supporting long-term planning of waste-management systems under multiple uncertainties in the City of Regina, Canada. The method improves upon the existing inexact two-stage programming and mixed-integer linear programming techniques by incorporating uncertainties expressed as multiple uncertainties of intervals and dual probability distributions within a general optimization framework. The developed method can provide an effective linkage between the predefined environmental policies and the associated economic implications. Four special characteristics of the proposed method make it unique compared with other optimization techniques that deal with uncertainties. Firstly, it provides a linkage to predefined policies that have to be respected when a modeling effort is undertaken; secondly, it is useful for tackling uncertainties presented as intervals, probabilities, fuzzy sets and their incorporation; thirdly, it facilitates dynamic analysis for decisions of facility-expansion planning and waste-flow allocation within a multi-facility, multi-period, multi-level, and multi-option context; fourthly, the penalties are exercised with recourse against any infeasibility, which permits in-depth analyses of various policy scenarios that are associated with different levels of economic consequences when the promised solid waste-generation rates are violated. In a companion paper, the developed method is applied to a real case for the long-term planning of waste management in the City of Regina, Canada.     

Two-Compartment Sorption of Phenanthrene on Eight Soils with Various Organic Carbon Contents

Sorption characteristics of phenanthrene (PHE) were studied on eight soils with organic carbon contents spanning over an order of magnitude using phase distribution relationships (PDRs) at 1 h, 48 h, and 720 h contact times. A new algebraic method was employed to describe the sorption characteristics at different time intervals (between 1 h and 48 h, and 1 h and 720 h). It was found that nonlinearity increased with increasing contact time and sorption that occurred in the subsequent time interval following the initial 1 h exhibited stronger isotherm nonlinearity. Sorption coefficients were positively correlated with the organic carbon contents of the soils. Detailed sorption dynamics were also examined on these soils. A two-compartment, first-order model was used to describe the sorption dynamics. The rate constants of the two compartments differed 18–170 times, suggesting the dissimilar sorption behaviors of the mathematically separated compartments. These two compartments were labeled fast and slow sorption compartment according to the rate constants. Calculation showed that the fast compartment accounted for over 80% of the overall sorption at the initial 1 h, while the slow compartment predominated the total sorption in the following 47 h. By combining the discussion of PDRs and sorption dynamics, the contributions of the two compartments to linear and nonlinear sorption were differentiated. The slow sorption compartment made a major contribution to nonlinear sorption and possibly to sequestration of organic pollutants by these soils.     

Identification of weather patterns impacting 24-h average fine particulate matter pollution

Methods are presented to extract intra-seasonal meteorological patterns at three scales to explain 24-h fine particulate matter (PM_2.5) pollution events: evolving large-scale meteorological scenarios, synoptic regimes driving diurnal variability near the surface, and localized meteorological triggers. The methods were applied to understand how winter weather conditions impacted PM_2.5 around the San Francisco Bay Area (SFBA). Analyzing data across 12 winters (November–March) ensured robust characterization of the SFBA conditions. SFBA 24-h PM_2.5 exceedances (35 μg m^?3) required several simultaneous characteristics: a ridge of aloft high pressure moving over SFBA, providing weak surface pressure gradients over Central California; persistent easterly flows through SFBA extending vertically to around the 925-hPa pressure level; orographically channeled winds resulting from stability; enhanced nocturnal cooling under clear-sky conditions providing for enhanced drainage flows off the Central California slopes; and at least two consecutive days of these conditions.