Adsorption and membrane separation for removal and recovery of volatile organic compounds

Volatile organic compounds(VOCs) are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity, high volatility, and poor degradability. It is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent regulations. In China, clear directions and requirements for reduction of VOCs have been given in the “national plan on environmental improvement for the 13th Five-Year Plan period”. Therefore, the de...     

中国地理资源期刊集群微信融平台经营的实践与经验

随着官媒时代的终结,以微信公众号为代表的新媒体的盛行,强烈地冲击着传统纸媒。微信公众号能够增加期刊与读者群之间的“粘性”,从而扩大期刊的学术影响力和社会知名度。在中国地理资源期刊网微信公众号的运行实践基础上,系统总结期刊微信融平台经营的实践与经验,并以《地理研究》等数据为例,阐述微信推送对期刊产生的综合作用,以期为科研微信融平台的运行提供指导和借鉴意义。研究结果表明：（1）科研微信融平台上生产好微推需遵守十四条原则、十一条创意要求;（2）坚持不懈地在微信公众号上发送消息,可以增加编辑与读者之间的交流、拓展读者范围、增加文章的下载量和被引量,从而树立学术期刊的品牌形象,提升期刊的学术影响力;（3）集群化的科研微信融平台的运行,一定要注意共同维护平台形象、谁制作谁负责、合理安排发文量和发文时间、个刊微平台实现互补等。持续地创意和推出微推,需要长期坚持,把期刊编辑和学术研究、移动互联时代、全媒体手段等积极“融”起来,实现期刊由传统纸质出版向富媒体出版、期刊由文献生产者向学科与社会集成型知识服务提供平台的两大根本性转型,才是期刊的根本出路。     

Silver recovery as Ag0 nanoparticles from ion-exchange regenerant solution using electrolysis

Many silver(Ag)containing consumer-products(e.g.textiles)release Ag into the environment,posing ecotoxicological risks.Ag recovery mitigates environmental hazards,recycles Ag,and leads to sustainability.In the present work,Ag has been recovered as Ag~0nanoparticles from the spent solution(thiourea(TU)～0.5 mol/L pH～1.1–1.2,and Ag～550 mg/L)obtained from the regeneration of an Ag-loaded resin using a simple undivided electrolytic cell.The reclaimed regenerant solution has been recycled and reused in a closed-loop scheme over multiple cycles.The process parameters,i.e.,current(0.05 A)and stirring speed(600 r/min),have been optimized for Ag recovery of～94%and TU loss of～2%.The reclaimed regenerant solution has been shown to regenerate Ag-loaded resin samples with90%regeneration efficiency over 4 cycles of consecutive extraction and regeneration.The recovered Ag~0nanoparticles are monodisperse,consistently spherical in shape,and have a mean diameter of～6 nm with standard deviation of the Gaussian fit as～2.66 nm.     

厌氧氨氧化-羟基磷灰石颗粒污泥系统的快速启动

为研究厌氧氨氧化-羟基磷灰石（Anammox-HAP）颗粒污泥系统的启动方法,采用厌氧氨氧化膨胀床反应器（AAFEB）,接种少量厌氧氨氧化污泥,通过调控基质浓度和水力停留时间,考察系统内污泥粒径及胞外聚合物（EPS）的变化,同时监测系统的脱氮除磷性能.结果表明,在低上升流速0.213~1.066m/h、Ca/P=5.5物质的量比的条件下,不断提高进水氮负荷,实现了Anammox颗粒污泥系统的启动.总氮、正磷酸盐去除率分别为（78.0±9.8）%、（63.8±9.9）%,总氮容积负荷达2.74kg/（m³·d）,在150d内培养出平均粒径为0.4mm的微颗粒污泥.颗粒的形态特征和元素分布检测表明其为Anammox-HAP颗粒污泥.随着颗粒污泥粒径的增加,EPS中的PS含量基本不变,PN从54.43mg/g增加到137.40mg/g,PN/PS从6.63提高到7.71.EPS中PN占比与粒径之间存在正相关,对污泥颗粒的形成起主要作用.     

Assessment of physical economy through economy-wide material flow analysis in developing Uzbekistan

In this paper, we assess the physical dimensions of Uzbekistan's economy during 1992–2011 by using the economy-wide material flow analysis (EW-MFA) method, which is an internationally recognized tool for such assessments. There have been a number of studies using methodological standardization of EW-MFA, but to the best of our knowledge, it has never been used to assess the metabolism of Central Asian economies, especially, in this case, the Republic of Uzbekistan.Our analysis strives to empirically evaluate macroscopic economic activities by considering the accounting of material flows. The material flows data-set comprises of consistent data for domestic extraction, imports, and exports, as well as other derived MFA-based indicators.The derived indicators are internationally compared for further evaluation of national economic development performance in a given period. The indicators of direct material input (DMI) and total material requirements (TMR) showed a slight increase in 1992–2011 with an average annual increase of 2.79% and 2.34%. The trends of TMR, DMI, domestic material consumption (DMC) and material efficiency, which is indicated by GDP/DMI, displayed lower values than other industrialized countries referenced in the international comparison. Although national economic performance data showed particularly remarkable success, indicators measuring material inputs and DMC reveal an insignificant increase during the period of study. During the second decade of study period, relative decoupling has occurred which indicated that the economic indicator (GDP) grows faster than DMC and other macro indicators grow.     

Allocation solutions for secondary material production and end of life recovery: Proposals for product policy initiatives

This paper aims at analysing how secondary materials production and end of life recovery processes are modelled in life cycle-based environmental assessment methods in order to discuss their suitability in product policy-support contexts, with a focus on Sustainable Consumption and Production (SCP) policies. The equations prescribed in three published, widely recognised standards are evaluated. In addition, more recent modelling approaches that have been adopted in the context of two EU product policy initiatives (the Product Environmental Footprint (PEF) and the Resource Efficiency Assessment of Products (REAPro)) are similarly analysed. All of the methods are scrutinised against eight criteria which we deem to be important in product policy-support contexts, including comprehensiveness, accommodation of open-loop and closed-loop product systems, and consideration of recyclability/recoverability rates, to name a few. Based on this analysis, it is suggested that the PEF and REAPro modelling approaches appear to be better suited for use in product policy-support contexts than do the currently widely endorsed methods that we considered.     

离子交换树脂在污泥处理中的应用及展望

离子交换树脂(IER)因其不溶性以及可循环利用性被广泛用于废水处理,但目前仍缺乏其对污泥应用研究的综述。本文汇总了污泥中常见IER类型(阳离子交换树脂、阴离子交换树脂以及螯合树脂),并介绍了树脂的基本特性以及适用的污泥方向,其中阳离子交换树脂,尤其是强酸性苯乙烯系阳离子交换树脂,适用范围最广。IER在污泥中的应用归为4类,分别为去除/回收重金属、回收磷、胞外聚合物提取以及调理污泥,并阐述了基本应用机理以及优缺点。针对IER在污泥中应用的不足,提出未来的研究方向,包括改性或开发新型IER去除/回收污泥中的重金属,优化IER直接回收污泥中磷的方法,改进IER调理污泥的方式以及开发新型分离IER与污泥的手段。本文有助于研究人员更好的了解IER在污水厂污泥中的应用现状,优化IER处理污泥的应用方式以及开发应用于污泥处理的新型IER。     

Incorporating Climate Science in Applications of the U.S. Endangered Species Act for Aquatic Species

Aquatic species are threatened by climate change but have received comparatively less attention than terrestrial species. We gleaned key strategies for scientists and managers seeking to address climate change in aquatic conservation planning from the literature and existing knowledge. We address 3 categories of conservation effort that rely on scientific analysis and have particular application under the U.S. Endangered Species Act (ESA): assessment of overall risk to a species; long‐term recovery planning; and evaluation of effects of specific actions or perturbations. Fewer data are available for aquatic species to support these analyses, and climate effects on aquatic systems are poorly characterized. Thus, we recommend scientists conducting analyses supporting ESA decisions develop a conceptual model that links climate, habitat, ecosystem, and species response to changing conditions and use this model to organize analyses and future research. We recommend that current climate conditions are not appropriate for projections used in ESA analyses and that long‐term projections of climate‐change effects provide temporal context as a species‐wide assessment provides spatial context. In these projections, climate change should not be discounted solely because the magnitude of projected change at a particular time is uncertain when directionality of climate change is clear. Identifying likely future habitat at the species scale will indicate key refuges and potential range shifts. However, the risks and benefits associated with errors in modeling future habitat are not equivalent. The ESA offers mechanisms for increasing the overall resilience and resistance of species to climate changes, including establishing recovery goals requiring increased genetic and phenotypic diversity, specifying critical habitat in areas not currently occupied but likely to become important, and using adaptive management. Incorporación de las Ciencias Climáticas en las Aplicaciones del Acta Estadunidense de Especies en Peligro para Especies Acuáticas     

Greenhouse evaluation and environmental impact assessment of different urine-derived struvite fertilizers as phosphorus sources for plants

A selection of six urine-derived struvite fertilizers generated by innovative precipitation technologies was assessed for their quality and their effectiveness as phosphorus sources for crops. Struvite purity was influenced by drying techniques and magnesium dosage. In a greenhouse experiment, the urine fertilizers led to biomass yields and phosphorus uptakes comparable to or higher than those induced by a commercial mineral fertilizer. Heavy metal concentrations of the different struvite fertilizers were below the threshold limits specified by the German Fertilizer and Sewage Sludge Regulations. The computed loading rates of heavy metals to agricultural land were also below the threshold limits decreed by the Federal Soil Protection Act. Urine-derived struvite contributed less to heavy metal inputs to farmland than other recycling products or commercial mineral and organic fertilizers. When combined with other soil conditioners, urine-derived struvite is an efficient fertilizer which covers the magnesium and more than half of the phosphorus demand of crops.     

Meta-analysis of the effects of upstream land cover on stream recovery

Unpredictable or variable ecosystem recovery from disturbance presents a challenge to conservation, particularly as the scale of human disturbance continues to increase. Theory suggests land-cover and disturbance characteristics affect recovery, but individual studies of disturbance and recovery frequently struggle to uncover generalizable patterns because of high levels of site-specific variation. To understand how land-cover, disturbance type, and disturbance duration influence ecosystem recovery, we used studies documenting recovery of 50 streams to perform a global meta-analysis of stream recovery from disturbances that affect water quality (e.g., oil spill, fire, wastewater). We extracted upstream natural and urban land-cover percentages for each site and performed model selection and averaging to identify influences on recovery completeness. Most streams improved following the end of a disturbance (median 240% of disturbed condition) but did not recover fully to baseline predisturbance condition within the studied period (median study period 2 years; median recovery 60% of baseline). Scale of disturbance in time and space did not predict recovery, but sites with higher percentages of upstream natural land cover had less complete recovery relative to sites with more urban or agricultural cover, possibly due to higher baseline conditions in these streams. Our findings suggest impacts to systems with low anthropogenic stress may be more irreversible than impacts to already modified systems. We call for more long-term evaluations of ecosystem response to disturbance and the inclusion of regional references and predisturbance reference conditions for comparison. A more thorough understanding of the role of the surrounding landscape in shaping stream response to disturbance can help managers calibrate expectations for recovery and prioritize protection.