Algae: the world��s most important ��plants����an introduction

Early in the history of life, algae changed the planet??s atmosphere by producing oxygen, thus paving the way for the evolution of eukaryotic organisms. In an era in which the consumption of fossil fuels is a prime topic of concern, few people realize that the oil we currently exploit comes mostly from Cretaceous deposits of marine algae. Moving from ancient times to the present, the algae remain more important than most people realize. Today, the production of oxygen by algae (ca. 50% of all oxygen production) is another reason for saying ??our lives depend on algae.?? Those who love seafood should thank the algae because algae are the primary producers upon which aquatic ecosystems depend. Thanks should come from all who are vegetarians or omnivores, because all land plants derive from a freshwater class of green algae and all land-animals??including the cows that provide the steaks for meat-lovers??depend directly or indirectly on land plants for food and often for shelter as well. As we use up the oil deposits provided by the ancient algae, we are turning to the modern algae for help. Given the photosynthetic abilities of the algae, they are one of the major focuses for sustainable biofuel production and CO₂ consumption. Finally, the algae that give us the air we breathe, the food we eat, and the fuel for our cars (past and, perhaps, future), are also a source of active pharmaceutical compounds that can be used against drug-resistant bacterial strains, viruses (including Herpes Simplex and AIDS), and cancers. Roses are pretty and oak trees are impressive, but no other groups of ??plants?? have done so much, for so long, and, for so many as have the algae!     

我国机动车排放标准的阶段跨越及其相关因素

汽车工业的未来发展将在社会经济可持续发展的总体战略之下计划和进行.本文从我国目前机动车的生产规模、我国未来机动车的市场、国民收入和城市道路等方面讨论了我国机动车未来发展趋势.以广州市为例,定量地分析了广州市机动车排放NOX的削减目标及控制措施的削减潜力和费用,结果表明,在广州市实现2010年的NO_X环境目标,必须提前实施EURO3标准.讨论了机动车标准阶段跨越的技术可行性及燃油质量的影响因素.     

Modern Biomass Conversion Technologies

This article gives an overview of the state-of-the-art of key biomass conversion technologies currently deployed and technologies that may play a key role in the future, including possible linkage to CO₂ capture and sequestration technology (CCS). In doing so, special attention is paid to production of biofuels for the transport sector, because this is likely to become the key emerging market for large-scale sustainable biomass use. Although the actual role of bio-energy will depend on its competitiveness with fossil fuels and on agricultural policies worldwide, it seems realistic to expect that the current contribution of bio-energy of 40–55 EJ per year will increase considerably. A range from 200 to 300 EJ may be observed looking well into this century, making biomass a more important energy supply option than mineral oil today. A key issue for bio-energy is that its use should be modernized to fit into a sustainable development path. Especially promising are the production of electricity via advanced conversion concepts (i.e. gasification and state-of-the-art combustion and co-firing) and modern biomass derived fuels like methanol, hydrogen and ethanol from ligno-cellulosic biomass, which can reach competitive cost levels within 1–2 decades (partly depending on price developments with petroleum). Sugar cane based ethanol production already provides a competitive biofuel production system in tropical regions and further improvements are possible. Flexible energy systems, in which biomass and fossil fuels can be used in combination, could be the backbone for a low risk, low cost and low carbon emission energy supply system for large scale supply of fuels and power and providing a framework for the evolution of large scale biomass raw material supply systems. The gasification route offers special possibilities to combine this with low cost CO₂ capture (and storage), resulting in concepts that are both flexible with respect to primary fuel input as well as product mix and with the possibility of achieving zero or even negative carbon emissions. Prolonged RD&D efforts and biomass market development, consistent policy support and international collaboration are essential to achieve this.     

Standardized and simplified life-cycle assessment (LCA) as a driver for more sustainable biofuels

The assessment of environmental impacts along the life cycle of biofuels is a complex and resource-demanding task that cannot be afforded by small producers in developing countries. Therefore, certification schemes bear the risk that small and independent producers will be locked out and the market for sustainable biofuels will be dominated by international investors and large-scale plantations. However, many environmental impacts of various production chains of biofuels and feedstocks are already known. This knowledge has been used to create a web-based questionnaire for a “Sustainability Quick Check for Biofuels” (SQCB, http://www.sqcb.org). SQCB reduces the need for user entries to the most relevant and best-known parameters of the biofuel production chain. Based on this user input, a specific inventory is automatically modelled and linked to background data. SQCB then calculates the environmental impact assessment and checks the results against sustainability criteria. Since the results are calculated immediately, key environmental factors can be interactively analyzed. One major goal of the SQCB is to support the market entrance for local biofuel producers, given that strengthening local stakeholders is a key driver for empowering rural communities in development countries.     

Production of biofuels from microalgae

The production of biofuels from microalgae, especially biodiesel, has become a topic of great interest in recent years. However, many of the published papers do not consider the question of scale up and the feasibility of the various processes to be operated at the very large scale required if algal biofuels are to make a meaningful contribution to renewable fuels. All the steps in the process must also be very low cost. This paper discusses the unit processes required for algal biofuels production (i.e., growing the algae, harvesting, dewatering, extraction and conversion to biofuel) and their scalability. In many cases, especially in the lipid extraction step, little is known as yet as to the scalability and economic feasibility of the various processes proposed. We also highlight the key engineering and biological issues which must be resolved for the production of biofuels from microalgae to become an economic reality.     

推行清洁生产建设节水型社会

水是人类赖以生存的资源,随着我国人口增长和经济的快速发展,水资源已成为目前制约我国经济发展和社会进步的主要因素,因此必须从可持续发展的战略高度,进一步提高对加强水资源节约和保护重要性、紧迫性的认识,增强水忧患意识、节水意识和水资源保护意识,推行清洁生产,建设节水型社会,加强水资源保护,以水资源的可持续利用来保障经济社会可持续发展.     

Biofuels production in developing countries: assessing tradeoffs in welfare and food security

In light of the recent rise in global food prices, much of the literature on crop-based biofuel production focuses on the potential impacts on food security. Studies have identified linkages between the usage of feedstocks in biofuel production and international food price increases. In addition, these studies indicate that food prices are expected to continue to rise over the next decade in response to biofuel consumption targets adopted in the U.S. and E.U. Despite these indications, some countries for whom food security and poverty reduction are still an issue have initiated crop-based biofuel development and set forth national blending targets for energy use within the transportation sector. As a result, a broader examination of the tradeoffs concerning welfare and food security related to biofuel development merit consideration. Opportunities to generate income and expand agricultural production technology through biofuel development may provide welfare gains that can improve purchasing power and decrease vulnerability to price shocks for food and energy. In addition, biofuel production schemes that promote alternative energy sources for household uses can improve productivity and health, especially for women and children. To assist with the sector development that maximizes welfare gains, we suggest a number of key indicators that might be useful in constructing a typology that can be applied across countries to characterize their energy needs and better target the types of bioenergy uses that might be best suited for them. In addition, biofuel production models are reviewed and best-practices identified that can expand welfare gains for smallholders and the poor. Through these examples, we demonstrate a basis upon which policymakers might approach the prioritization of their national strategies towards developing renewable energy sources, such that they can have the maximum impact upon important goals of human welfare and development.     

发展生物能源引发的土地利用问题

在经济发展不断增加对能源的需求和国际上减少温室气体排放的压力下,生物能源得到了各国政府的大力扶持并取得了快速发展。全球燃料乙醇生产总量1975年为5.68×108L,2000年增加到170×108L,2007年迅速增加到511×108L。生物柴油也自2000年的约9.1×108L迅速增加到2007年的132×108L。生物能源的迅速发展带来了关于其对粮食安全影响的激烈争论。论文从剖析近年来关于生物能源发展对粮食安全的影响入手,系统分析了耕地在生物能源生产及其效应研究中的重要作用、近年来生物能源发展占用耕地面积、对土地利用变化的影响及其对农户耕地利用决策行为的影响机制。研究发现:①土地作为生物能源生产的主要资源投入类型,是其对粮食安全产生影响的最重要媒介;②近年来生物能源占用耕地面积呈不断增加趋势,2004年,全球生物能源占地1 400×104hm2,约为全球耕地总面积(140 583×104hm2)的1%,到2007年,占地4 221.7×104hm2,相当于2004年的3.05倍,据保守估计到2030年,将占地5 300×104hm2;③发展生物能源直接带来林地、草地和农用地等土地利用类型之间,以及不同农作物类型之间的土地利用冲突,并带来土地利用方式的显著变化;④从农户尺度看,相对于粮食作物,能源作物具备较高的经济收益,根据对广西武鸣县的农户调查得出,2009年木薯纯收益为11 123.04元/hm2、甘蔗为12 138.36元/hm2,远远高于稻谷(6 984.04元/hm2)、玉米(5 104.61元/hm2)、花生(2 851.36元/hm2),收益上的比较优势是其播种面积不断增加的根本原因。     

确立环境资源的价值观 促进经济与环境持续协调发展

面对发展经济、保护环境的双重挑战,必须提高全民的可持续发展意识,确立环境资源的价值观,利用价值规律,采用多种经济手段管理环境资源。      

The energy-environment nexus: aerosol science and technology enabling solutions

Energy issues are important and consumption is slated to increase across the globe in the future. The energy-environment nexus is very important as strategies to meet future energy demand are developed. To ensure sustainable growth and development, it is essential that energy production is environmentally benign. There are two temporal issues—one that is immediate, and needs to address the environmental compliance of energy generation from fossil fuel sources; and second that is the need to develop newer alternate and more sustainable approaches in the future. Aerosol science and technology is an enabling discipline that addresses the energy issue over both these time scales. The paper is a review of aspects of aerosol science and engineering that helps address carbon neutrality of fossil fuels. Advanced materials to meet these challenges are discussed. Future approaches to effective harvesting of sunlight that are enabled by aerosol studies are discussed.     

Hydrogen for a sustainable global economy

The topic of this special issue of the Journal of Cleaner Production is “Sustainable Hydrogen from Biomass.” It is of interest to practitioners in the energy sector, governmental policy makers, researchers, educators, as well as to the general public. The purpose of this special issue is to increase public awareness and to stimulate exchange of information among actors expected to play important roles in making hydrogen available for the sustainable energy system of the future.Hydrogen as a biofuel, that is, hydrogen produced from biomass in a sustainable way is recognised as an important component of the fuel market for the future low or non-carbon based energy systems. In this special issue, the main focus is on hydrogen produced from vegetable biomass by fermentation. The development of a two-stage bioprocess for the cost-effective and environmentally friendly production of pure hydrogen from multiple biomass feedstocks is elucidated by a collection of papers presenting preliminary results of Integrated Research Project HYVOLUTION supported by the 6th Framework Programme of the European Union. The attention is turned to:- the over-all concept and characteristics of the two-stage hydrogen fermentation process,- key technological issues of fermentative hydrogen production,- the availability of vegetable feedstocks including agricultural byproducts that suitable for fermentative processing,- prospects of societal integration and sustainability of the fermentative hydrogen production technology.Other papers included in this special issue are devoted to:- simultaneous production of hydrogen and methane by fermentation of lactose-containing feedstocks derived from byproducts of milk processing,- hydrogen gas generation from organic material by electrohydrogenesis, that is, a bioelectrochemical process performed in reactors known as a microbial electrolysis cells,- the ideas for Europe-wide effort on education of hydrogen users and training of skilled staff needed for facilitating the transition to the future hydrogen economy.     

Agro-ecological engineering in China: a way towards sustainableagriculture

ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｈｉｇｈｒａｔｅｏｆｔｈｅｗｏｒｌｄｅｃｏｎｏｍｉｃｇｒｏｗｔｈｉｎｔｈｉｓｃｅｎｔｕｒｙ ,ｍａｎｙｕｎｐｒｅｃｅｄｅｎｔｅｄ“ｅｃｏｌｏｇｉｃａｌｃｒｉｓｅｓ” ,ｓｕｃｈａｓｄｅｐｌｅｔｉｏｎｏｆｎａｔｕｒａｌｒｅｓｏｕｒｃｅｓ,ｅｎｖｉｒｏｎｍｅｎｔａｌｄｅｔｅｒｉｏｒａｔｉｏｎ ,ｓｏｉｌｅｒｏｓｉｏｎ ,ｄｅｃｅｒｔｉｆｉｃａｔｉｏｎ,ａｎｄｇｌｏｂａｌｃｈａｎｇｅ,ｈａｖｅｂｒｏｋｅｎｏｕｔａｌｌｏｖｅｒｔｈｅｗｏｒｌｄ .Ｍａｎｙｅｖｉｄｅｎｃｅｓｉｎｄｉｃａ…     

国土空间规划视角下海陆统筹的挑战与路径

通过梳理国内外海陆统筹实践进程和政策演变,界定海陆统筹的基本概念与内涵,在国土空间规划背景下,探讨海陆统筹的关键问题和挑战,并进一步提出海陆统筹的优化路径。研究表明：（1）海陆统筹是一种“流”空间理论思维下面向全域全要素的开发保护战略,通过统一筹划海陆两大系统的资源要素配置、产业联动、生境共治、空间互联和制度互嵌,促进沿海地区协同高效发展,提升生产、生活和生态空间品质。（2）国土空间规划视角下海陆统筹面临的主要问题与挑战包括：海陆空间边界不明晰、海陆经济系统不协调、海陆资源开发与生境保护不统一和海陆空间规划体系不兼容。（3）针对现状问题与挑战,基于空间、经济、生态和管治四个维度,构建全域全要素、分级、分功能的统筹优化路径,以期为沿海地区的海陆协调发展提供借鉴。     

氟化工行业循环经济模式构建研究

氟化工是化工行业中发展最快、最具高新技术和最有前景的行业之一。如何使该行业持续健康发展,走循环经济是其根本出路。文章中论述了氟化工企业目前存在的主要问题,提出了氟化工企业实施循环经济的基本途径,并以青海某氟化工企业为实例,论述了该氟化工企业从延长产业链、采用清洁生产工艺、能源回收利用、水资源利用、固废资源综合利用、工艺尾气资源利用等方面构建循环经济模式,为同类型氟化工企业循环经济建设提供参考。     

Microalgae cultivation using an aquaculture wastewater as growth medium for biomass and biofuel production

Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%–95% for nitrogen and 98%–99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production.     

基于生态足迹我国三大经济圈可持续发展能力研究

本文基于当前国际上流行的生态足迹(Ecological Footprint,简称EF)模型,以可持续发展理论、区域经济学理论、生态经济理论等相关理论为基础,理论分析与实证分析、定性分析与定量分析相结合的原则,采用社会经济各相关部门的统计数据、相关研究报告的资料,针对中国东部地区三大经济圈的实际情况,建立了区域可持续发展评价指标,评价了三大经济圈的可持续发展能力,明确了当前三大经济圈社会经济发展所处的状态、存在的问题,研究结果可以为制定保证三大经济圈社会、经济实现可持续发展的政策提供科学依据和指导.研究表明,我国三大经济圈可持续发展能力较差,内部的经济与环境不协调性以及不合理的经济结构是制约三大经济圈可持续发展的主要问题.     

Microalgae cultivation using an aquaculture wastewater as growth medium for biomass and biofuel production

Microalgae as a main feedstock has attracted much attention in recent years but is still not economically feasible due to high algal culture cost. The objective of this study was to develop a comprehensive eco-friendly technology for cultivating microalgae Platymonas subcordiformis using aquaculture wastewater as growth medium for biomass and biofuel production. Platymonas subcordiformis was grown in pretreated flounder aquaculture wastewaters taken from different stages. Each of wastewater contained different levels of nutrients. The biomass yield of microalgae and associated nitrogen and phosphorous removal were investigated. The results showed that algal cell density increased 8.9 times than the initial level. Platymonas subcordiformis removed nitrogen and phosphorus from wastewater with an average removal efficiency of 87%-95% for nitrogen and 98%-99% for phosphorus. It was feasible to couple the removal of nitrogen and phosphorus from wastewater to algal biomass and biofuel production. However, further studies are required to make this technologies economically viable for algae biofuel production.     

Utilising renewable resources economically: new challenges and chances for process development

In recent years a considerable increase in interest in the development of processes based upon renewable resources has occurred. One reason for this development is the call for more sustainable and environmentally benign production processes and products.Increased utilisation of renewable resources, however, poses new challenges to chemical and process industries. These challenges arise from increased competition for renewable but still finite resources, the de-centralised production of the renewable resources and the complexity of the raw materials. These new challenges require new approaches to process development, as production systems become more complex and interlinked, logistical considerations become increasingly important and new technological solutions must be adapted to local and regional settings. As the structure of complex production systems must be newly developed and optimised, process synthesis will play an increasingly important role in process development.     

公路可持续发展若干问题分析

根据可持续发展发展内涵的代际公平性、资源限制性、发展协调性和质量效益型发展要求，分析了湖北省公路发展现状，提出了“代际单元”概念，提出了考虑代际公平的决定性影响，对公路设计、施工和营运三个阶段中环境保护的实施进行了打分评价，得出了公路目前还远离可持续发展状态的结论，强调了公路实施可持续发展的要点。