Global potential of phosphorus recovery from human urine and feces

This study geospatially quantifies the mass of an essential fertilizer element, phosphorus, available from human urine and feces, globally, regionally, and by specific country. The analysis is performed over two population scenarios (2009 and 2050). This important material flow is related to the presence of improved sanitation facilities and also considers the global trend of urbanization. Results show that in 2009 the phosphorus available from urine is approximately 1.68 million metric tons (with similar mass available from feces). If collected, the phosphorus available from urine and feces could account for 22% of the total global phosphorus demand. In 2050 the available phosphorus from urine that is associated with population increases only will increase to 2.16 million metric tons (with similar mass available from feces). The available phosphorus from urine and feces produced in urban settings is currently approximately 0.88 million metric tons and will increase with population growth to over 1.5 million metric tons by 2050. Results point to the large potential source of human-derived phosphorus in developing regions like Africa and Asia that have a large population currently unserved by improved sanitation facilities. These regions have great potential to implement urine diversion and reuse and composting or recovery of biosolids, because innovative technologies can be integrated with improvements in sanitation coverage. In contrast, other regions with extensive sanitation coverage like Europe and North America need to determine how to retrofit existing sanitation technology combined that is combined with human behavioral changes to recover phosphorus and other valuable nutrients.     

Goshute Native American Tribe and Nuclear Waste: Complexities and Contradictions of a Bounded-Constitutive Relationship

This essay examines discourse from members of the Skull Valley Goshute Native American tribe about the nuclear-waste proposal and tribal controversy. Building from Kinsella's “bounded-constitutive” theoretical model of communication, I argue the environment (material) is more than a context where Goshute culture and policy development (symbolic) plays out. Rather, environment, culture, and policy mutually define each other, and the material environment constrains Goshute culture. Instead of the symbolic unilaterally influencing the material, the material responds and acts to influence the symbolic. The symbolic becomes responsible to the material and vice versa as the relationship is multi-influential and interactive creating political, cultural, and environmental complexities and contradictions while fueling intra-tribal conflict.     

E-waste assessment methodology and validation in India

An attempt has been made to establish an approach and a methodology to quantify electronic waste (e-waste) in India. The study was limited to personal computers (PCs) and televisions (TVs) within the state boundaries of Delhi and in selected areas in the National Capital Region (NCR). Material flow analysis was used to establish an e-waste trade value chain, where cathode ray tubes (CRTs) were tracked in the e-waste dismantling stream of the CRT regunning process. The market supply method was used to estimate the theoretical amount of e-waste for each item. Sensitivity analysis was carried out for PCs, using 5 years and 7 years as the average life, and for TVs, using 10 years and 12 years as the average life. Externalities such as e-waste entering the study area from outside were factored into the final e-waste analysis. Sensitivity analysis on the average life also factored in elements of active usage, reuse, and storage of electronic items and consumer behavior into assumptions about the obsolescence rate in market supply method. A primary survey indicated an output of 1800–2100 CRTs per day from all regunning units in the study area. This range validated the theoretical output for an average life of 7 years for a PC and 12 years for a TV. Using this approach, e-waste was estimated to reach 2 million units from the domestic market by 2010.     

现代铝业生态环境系统研究

资源和环境问题是我国面临的严重的生态安全和环境安全问题,也是制约我国工业可持续发展的战略问题。生态铝业是与环境协调发展的环境友好的工业体系,它有效地解决了传统铝业发展和生态环境保护之间的矛盾。传统铝业耗电量大、污染严重、生产成本高;现代铝业属于生态工业,它以循环经济为指导,推行清洁生产,发展热电联产,促进污染物的资源化,减少废弃物的排放,降低了铝业生产的物耗、能耗和生产成本,增加了市场竞争力,形成整个工业系统的良性循环。笔者提出了现代铝业生态系统的框架,并简单介绍了主要子系统的清洁生产途径。以期抛砖引玉,促进现代铝业生态环境系统的研究,推动生态铝业在我国的实践和发展。     

Nitrogen Flow Analysis in Huizhou, South China

Eutrophication due to uncontrolled discharges of nitrogen and phosphorus has become a serious pollution problem in many Chinese rivers. This article analyzes the nitrogen flow in Huizhou City in the East River watershed in south China. The material accounting method was applied to investigate the nitrogen flows related to human activities, which consist of the natural and anthropogenic systems. In Huizhou City, the nonpoint source pollution was quantified by the export coefficient method and the domestic discharge was estimated as the product of per capita nitrogen contribution and population. This research was conducted based on statistical information and field data from 1998 in the Huizhou City. The results indicated that the major nitrogen flows in this area were river loads, fertilizer and feedstuff imports, atmospheric deposition, animal manure volatilization, and processes related to burning and other emissions. In 1998, about 40% of the nitrogen was retained in the system and could result in potential environmental problems. Nitrogen export was mainly by rivers, which account for about 57% of the total nitrogen exported. Comparisons made between the East River and the Danube and Yangtze Rivers show that the unit area nitrogen export was of the same magnitude and the per capita nitrogen export was comparable.     

中药免疫增强剂抗肿瘤作用机理及物质基础

近年来,中药免疫增强剂的作用机理及物质基础逐渐被现代医学不断研究揭示.研究表明中药中的多糖类,苷类,黄酮类,挥发油类等成分能提高机体的免疫能力,能够明显增强免疫器官的重量,增强体液免疫和细胞免疫及促进机体产生细胞因子等作用.参31.     

An interregional ecological approach for modelling sustainability in a globalizing world—Reviewing existing approaches and emerging directions

In recent decades international trade has become a major source of supplying the need and wants of billions of people around the world. Virtually everyone now consumes resource commodities and manufactured products imported from ‘elsewhere’. In effect, globalization and trade enable consuming populations to support themselves on the output of distant ecosystems half a world away. However, while economic integration implies greater ‘connectivity’ within the global village, the spatial separation of material production (including resource extraction) from consumption eliminates some of the signals i.e., the negative feedbacks coming from supporting eco-systems from reaching those who depend on these ecosystems for their sustainability. At present, despite increasing global connectedness, most environmental studies and models apply to a single spatial scale: local, national or global; analysing diverse pressures on human well-being and ecosystems integrity. This paper argues that both economic globalization and global ecological change should force us to add an interregional scale for quantifying and modelling sustainability. Such an approach recognizes that, in a globalizing world, the sustainability of any given region increasingly depends, directly and indirectly, on the sustainability of many other regions. The following pages describe the interregional approach and illustrate some existing and emerging methods for quantifying, analysing and modelling interregional linkages. It then identifies some of what is still missing, and discusses some of the implications in a changing world.     

International aspects of recycling of electrical and electronic equipment: material circulation in the East Asian region

This article examines the present circumstances of recycling of end-of-life electrical and electronic equipment discarded in Japan from the domestic and international viewpoints of material circulation. It is pointed out that some of the discarded items are absorbed into an invisible flow by informal economic activities, being exported in the form of secondhand equipment and secondary materials. Since the equipment has a pollution potential as well as a resource potential, it is anticipated that the pollution potential may possibly be realized if the equipment is mishandled at recycling plants in developing countries. To reduce the invisible flow as much as possible and to reduce the pollution potential from diffusion in developing countries, a policy tool such as extended producer responsibility should be applied to retailers of the equipment, as well as to producers.     

Modeling obsolete computer stock under regional data constraints: An Atlanta case study

In this paper, we report on our efforts to develop a research framework that can be used to quantify waste flows for different geographical areas in the face of limited waste data availability. We demonstrate this framework in our case study of obsolete computers in the Atlanta metropolitan area. We develop computer obsolescence rates at the national metropolitan level, and couple this data with economic information at the census tract level to generate product inventory estimates (PIE) of the stock of obsolete computers from both business and household sectors in the Atlanta metropolitan area. We seek to improve the accuracy of waste flow estimates for specific geographic areas over those of previous studies, provide an easily replicable and cost effective methodology, highlight the ensuing spatial implications for collection and recycling systems using GIS, and demonstrate the potential economic benefits from diverting electronic wastes within a region. The modeling framework we have developed is intended to be applicable to other regions and to other medium range durable goods discarded by households, businesses, or obtained from buildings.     

对循环经济概念及内涵的再思考

在总结各种循环经济概念的基础上,结合当前循环经济发展的实践,对循环经济概念及内涵进行了再思考。认为循环经济是勃质流动的全过程防治污染,充分利用资源,实现人与自然和谐的可持续经济发展模式。