水环境中新兴污染物三氯蔗糖的研究进展

人工甜味剂——三氯蔗糖（sucralose,SUC）是一种应用广泛的食品添加剂,因其在水环境中被广泛检出,且具有高极性、持久性等特点,被US EPA（美国环境保护局）列为新兴污染物（emerging contaminant,EC）,相关检测、降解及毒理学研究逐渐增多.在比较了水环境中微量三氯蔗糖检测方法,总结了其在各地水环境中检出情况的基础上,重点阐述水处理工艺中三氯蔗糖的控制及转化.研究表明:固相萃取-液质联用（SPE-LC/MS）是检测水环境中人工甜味剂最常用的方法,可实现痕量三氯蔗糖的准确定性和定量,检测限低至几ng/L.以生物处理为主的污水处理工艺对三氯蔗糖降解效果甚微,大部分三氯蔗糖随排放进入水环境,继而进入饮用水处理及供水系统.欧美地区污水及地表水环境中三氯蔗糖检出浓度约为几至几十μg/L,饮用水中约为几百ng/L,国内水环境中检出水平与之相当,但资料数据相对匮乏.饮用水常规处理工艺对三氯蔗糖几乎没有控制效果,实际处理系统中氯和臭氧等氧化工艺控制效果甚微.试验研究中以产生羟基自由基、硫酸自由基等为主的高级氧化工艺可有效降解三氯蔗糖,但由于成本高,操作条件限制等难以大规模应用,此外三氯蔗糖降解过程中可能产生有害副产物.我国已经成为三氯蔗糖的第二大产地,人工甜味剂生产及使用规模大,理论上国内存在水环境污染范围广、污染水平高的分布特征,是水源中不容忽视的一类微量有机污染物.目前国内净水厂推广应用以臭氧为主的深度处理工艺,但三氯蔗糖在该工艺中因不完全降解可能导致多种含氯或脱氯产物的产生,对饮用水供水安全具有潜在威胁.      

Financial viability of reforesting reclaimed surface mined lands, the burden of site conversion costs, and carbon payments as reforestation incentives

US Federal law mandates that mined land be returned by mine operators to a condition capable of supporting its pre-mining use or a higher use. Previously forested lands have commonly been reclaimed to hayland/pasture or wildlife habitat, and most of these lands have been abandoned from management and rendered non-productive. This situation has left landowners in the position of converting these reclaimed mined lands to forests at a later date, if they choose to make them economically productive. Such land-use conversion, however, comes with a substantial up-front cost to the landowner, which makes the financial viability of such a conversion questionable. We examine the financial viability of reforestation of these previously reclaimed mine lands by calculating land expectation value (LEV) under a range of conditions that include forest type, site quality, and reforestation intensity. We find that conversion to white pine is viable on higher quality sites under low to moderate interest rates with low or high timber prices, but conversion to mixed hardwoods is only profitable under the high price scenario with low interest rates, and only on higher quality sites. We also consider the implications of a shift in reforestation burden from the landowner to the mine operator, and results suggest that including costs of reforestation as part of the mining operation creates a financially viable forest enterprise for landowners under all scenarios for both white pine and mixed hardwoods. Two forms of carbon payments that could encourage reforestation of previously reclaimed mined lands also are examined: an annual payment based upon the total accumulated carbon found on-site in a given year, and an annual payment based on only the increment of carbon storage each year. Our carbon payment results indicate that annual values of up to $5.17 per ton of carbon stored in hardwoods and $9.39 per ton of carbon stored in pines would be required to make reforestation profitable under the poorest conditions (high interest rates, low prices, and poor quality site) when the payment is based on accumulated on-site carbon, although lower values are required under more favorable scenarios. Payments that are based upon the annual increment of carbon must fall in the range of $8.66–$71.88 per ton of carbon stored in hardwoods and $0–$83.29 per ton of carbon stored in pines to make reforestation financially viable.     

Market imperfections in recycling markets: conceptual issues and empirical study of price volatility in plastics

The effectiveness of recycling depends upon efficient functioning of secondary material markets. This paper focus on the role that price volatility can play in slowing investment and market development. However, a statistical analysis of the relative volatility of secondary and primary material prices does not confirm the widely-held belief that relative price volatility is higher in secondary than in primary materials, at least at national levels.An econometric estimation of the determinants of plastic recovery volumes in Seattle contributes to the literature in four ways: the use of monthly (as opposed to annual) data; the use of local (as opposed to national) data; the use of an explanatory variable to reflect price volatility; and, the focus on plastics, which have not been examined previously. Some tentative conclusions can be made: the results generally support the principal hypothesis that price volatility has a negative effect on recovery of secondary materials; in addition, and consistent with previous studies, price elasticities are low and insignificant; and finally, policy factors are clearly important. The concluding section treats the economic and policy implications of market inefficiency in secondary material markets.     

Reprint of “The future of hydropower in Europe: Interconnecting climate,markets and policies”

Hydropower is very important for electricity supply security in the European inter-connexion as well as for the economy of regions (primarily peripheral) that possess water resources. Its future may however be jeopardized by several factors: climate change, the development of new renewable energy, the creation of super and micro-grids, and progress in power storage technology. Energy and climate policy, as well as electricity market design and dynamics play a pivotal role.This article carries out a comprehensive analysis of all these factors and discusses the future of hydropower. This discussion follows an overview of the present situation and of future drivers. The technical, environmental, economic and political aspects of the problem are analyzed with an interdisciplinary approach. The stakes as well as the uncertainties are highlighted.The conclusion is that hydropower has a promising future, particularly in light of emerging sustainable energy policy, but that the risks should not be overlooked. Academics will find a comprehensive interdisciplinary analysis of hydropower in this article, whereas public bodies, communities and hydropower companies can identify the strategic variables that should be taken into consideration in the decision making process. The end of water concessions or authorizations is also evoked.     

Conspicuous conservation: The Prius halo and willingness to pay for environmental bona fides

This paper develops a theory of conspicuous conservation, a phenomenon related to conspicuous consumption in which individuals seek status through displays of austerity amid growing concern about environmental protection. We identify a statistically and economically significant conspicuous conservation effect in vehicle purchase decisions and estimate a mean willingness to pay for the green signal provided by the distinctively designed Toyota Prius in the range of $430–4200 depending upon the owner's location. Results are related to the growing literature on green markets and suggest that policy should target less conspicuous conservation investments that will be under-provided relative to those that confer a status benefit.     

上海某城市污水处理厂污水中药物和个人护理用品(PPCPs)的调查研究

通过两次采集上海某大型污水处理厂的水样,采用超高效液相色谱-串联质谱(UPLC-M S/MS)技术对水样中的94种典型药物和个人护理用品(PPCPs)进行分析,并初步分析了污水处理工艺对典型药物的处理效果.结果显示,该厂污水中有咖啡因、布洛芬、酮洛芬、双氯酚酸、氧氟沙星、睾酮、诺龙、磺胺吡啶、磺胺甲恶唑、甲砜霉素、氟甲砜霉素、氯贝酸、磺胺二甲基嘧啶、磺胺间甲氧嘧啶、氯霉素和诺龙等15种药物被检出和定量.初沉出水中药物总浓度为8 643～10 481 ng·L1,主要为咖啡因,出厂水中药物总浓度为1 005 ～1 076 ng·L1.其中,磺胺二甲基嘧啶、甲砜霉素和氟甲砜霉素在相关报道中较少进行检测或没有检出.磺胺二甲基嘧啶、磺胺间甲氧嘧啶、氯霉素和诺龙4种药物经生化反应池(A/A/O)和二沉池处理之后未检出.以A/A/O为核心技术的污水处理工艺对咖啡因、氯霉素、甲砜霉素和诺龙等药物处理效率较好(85％～99％),但对大部分药物处理效果并不显著.     

A multi-mutualist simulation: Applying biological market models to diverse mycorrhizal communities

We present a cellular automaton that simulates the interaction between a host tree and multiple potential mycorrhizal symbionts and generates testable hypotheses of how processes at the scale of individual root tips may explain mycorrhizal community composition. Existing theoretical biological market models imply that a single host is able to interact with and select from multiple symbionts to organize an optimal symbiont community. When evaluating the tree–symbiont interaction, two scales must be considered simultaneously: the scale of the entire host plant at which carbon utilization and nutrient demands operate, and the scale of the individual root tip, at which colonization and carbon-nutrient trade occurs. Three strategies that may be employed by the host tree for optimizing carbon use and nutrient acquisition through mycorrhizal symbiont communities are simulated: (1) carbon pool adjustment, in which the plant controls only the total amount of carbon to be distributed uniformly throughout the root system, (2) symbiont selection, wherein the plant opts either for or against the interaction at each fine root tip, and (3) selective carbon allocation, wherein the plant adjusts the amount of carbon allocated to each root tip based on the cost of nutrients. Strategies were tested over various nutrient availabilities (the amount of inorganically and organically bound nutrients). Success was defined on the basis of minimizing carbon expended for nutrient acquisition because this would allow more carbon to be utilized for growth and reproduction. In all cases, the symbiont selection and selective carbon allocation strategies were able to meet the nutritional requirements of the plant, but did not necessarily optimize carbon use. The carbon pool adjustment strategy is the only strategy that does not operate at the individual root tip scale, and the strategy was not successful when inorganic nutrients were scarce since there is no mechanism to exclude suboptimal symbionts. The combination of the symbiont selection strategy and the carbon pool adjustment resulted in optimal carbon use and nutrient acquisition under all environmental conditions but result in monospecific symbiont assemblages. On the other hand, the selective carbon allocation strategy is the only strategy that maintained successful, multi-symbiont communities. The simulations presented here thus imply clear hypotheses about the effect of nutrient availability on symbiont selection and mycorrhizal community richness and composition.     

EFFECTS OF INCREASED DELTA EXPORTS ON SACRAMENTO VALLEY'S ECONOMY AND WATER MANAGEMENT1

ABSTRACT: Exports from the Sacramento‐San Joaquin Delta are an important source of water for Central Valley and Southern California users. The purpose of this paper is to estimate and analyze the effects increased exports to south of Delta users would have on the Sacramento Valley economy and water management if water were managed and reallocated for purely economic benefits, as if there were an ideal Sacramento Valley water market. Current Delta exports of 6,190 thousand acre‐feet per year were increased incrementally to maximum export pumping plant capacities. Initial increases in Delta exports did not increase regional water scarcity, but decreased surplus Delta flows. Further export increases raised agricultural scarcity. Urban users suffer increased scarcity only for exports exceeding 10,393 taf/yr. Expanding exports raises the economic value of expanding key facilities (such as Engle bright Lake and South Folsom Canal) and the opportunity costs of environmental requirements. The study illustrates the physical and economic capacity of the Sacramento Valley to further increase exports of water to drier parts of the state, even within significant environmental flow restrictions. More generally, the results illustrate the physical capacity for greater economic benefits and flexibility in water management within environmental constraints, given institutional capability to reoperate or reallocate water resources, as implied by water markets.     

新兴污染物对微藻的毒性作用与机制研究进展

随着科技的发展,监测手段不断进步,新兴污染物普遍存在于环境中的问题及其可能带来的危害近年来才开始受到重视和研究。微藻作为初级生产者,对维持生态系统的稳定和平衡起到了至关重要的作用。本文综述了包括全氟化合物、多环芳烃、药品及个人护理品、纳米材料、微塑料和稀土元素在内的新兴污染物对微藻毒性作用及机制的研究进展。重点针对微藻的种间关系、生长和形态、对污染物的吸收和代谢、氧化应激反应、光合作用及基因表达等方面进行了总结,分析了新兴污染物作用下微藻的响应规律,归纳了新型污染物作用于微藻的毒性影响与可能机制。最后思考了其中可能存在的问题,提出了几点建议和展望。     

Organizational adoption of sustainable manufacturing practices in India: integrating institutional theory and corporate environmental responsibility

Organizations are increasingly engaging in socially and environmentally sustainable initiatives. This paper focuses on the institutional isomorphism mechanisms to analyse the organizational adoption of sustainable manufacturing practices like eco-design, source reduction, and environmental management practices. This paper empirically examines the role of institutional influence in the organizational adoption of sustainable manufacturing practices among firms in India. The results of this study confirm the significance of the three institutional isomorphism mechanisms in influencing sustainable responses, but not all mechanisms influence the organizational response equally. In particular, the results show a strong influence of self-regulatory normative isomorphism on the implementation.