水解(酸化)——生物接触氧化处理水产品加工废水

对水解(酸化)-生物接触氧化工艺处理水产品加工废水进行了试验研究,试验结果表明在水温20℃、总HRT＞6h、进水COD值1000～1300mg/l、BOD5值510～690mg/l、SS值150～300mg/l情况下,COD去除率大于89%,BOD5去除率大于92%,SS去除率大于89%,出水COD、B0D5、SS值均达到国家二级排放标准(GB8978-1996),最高有机容积去除负荷达3.9kgCOD/m3@d.水产品加工废水经水解(酸化)处理以后BOD5/COD值可由原水的0.52提高到出水的0.67,可生化性得到显著提高.     

生态生产：一种重要的生产形式

生态生产指构成生态系统的各要素在相互依存、制约和作用过程中的物质循环和能量流动。一个健全的生态生产须具备两个基本条件，一是构成要素的不可缺少性或构成要素应有足够的数量保证，二是生态生产各要素之间要有一种优化协调的关系。长期以来，人们关注的主要是生态生产的社会化，而忽视了社会生产的生态化要求，结果造成社会生产与生态生产之间尖锐的矛盾，处理地社会生产与生态生产的相互关系，必须遵循物质生产和人口生产一定     

Screening life cycle assessment (LCA) of tomato ketchup: a case study

A screening life cycle assessment (LCA) of tomato ketchup has been carried out. The purpose was to identify ‘hot-spots', that is parts of the life-cycle that are important to the total environmental impact. The system investigated includes agricultural production, industrial refining, packaging, transportation, consumption and waste management. Energy use and emissions were quantified and some of the potential environmental effects assessed. Packaging and food processing were found to be hot-spots for many, but not all, of the impact categories investigated. For primary energy use, the storage time in a refrigerator (household phase) was found to be a critical parameter.     

国民生产总值“绿化”问题的综合分析

在环境科学领域中，通常把从环境的角度出发对国民生产总值ＧＮＰ进行改进的问题称为国民生产总值的“绿化”问题，本文综合地分析了国民生产总值这一指标中存在的问题和已有改进方法的不足，并提出了进一步改进的方向和应注意的问题．     

水解(酸化)处理水产品废水的生物降解动力学研究

对水解(酸化)反应器处理水产品加工废水进行了试验研究，研究结果表明，在水温为20℃左右、进水COD为1100mg／L左右、水力停留时间大于2h的条件下，无需曝气作用，水解(酸化)反应器对水产品加工废水中COD的去除率大于40％。水产品加工废水具有较好的可生化性，水解(酸化)反应器对该废水可生化性能的改善作用不明显。利用Eckenfelder生物滤池数学模式对水解(酸化)反应器进行了分析，得到了水解(酸化)反应器处理水产品加工废水的生物处理动力学方程：Sc／SD=e^-0.23D/L^0.24。     

Molarity provides better clarity – using molar-based data when evaluating chlorinated volatile organic compound impacted sites

Abstract

Chlorinated volatile organic compounds are common constituents observed at many contaminated groundwater sites. Common industry practice has been to measure these constituents in groundwater on a weight concentration basis (e.g. µg/l, mg/l). This paper highlights the use of molar-based concentrations, especially in the case of parent-daughter degradation sequences commonly observed with the chloroethene, chloroethane, and chloromethane families of compounds. Converting to molar-based concentrations provides the practitioner greater insight into groundwater plume behavior including better evaluation of degradation processes, remedial progress, possible commingling, and/or sourcing. For example, this paper provides a tank analogy to evaluate whether the commonly misinterpreted observation of “DCE-stall” may be occurring at a site. Multiple examples of the benefits of using molar-based concentration data are also summarized in a project case study presented herein. As demonstrated in this paper, molarity does provide better clarity and can be a powerful evaluation tool in the groundwater practitioner’s toolbox.     

Life Cycle Assessment as Part of Sustainability Assessment for Chemicals (5 pp)

Background LCA is the only internationally standardized environmental assessment tool (ISO 14040-43) for product systems, including services and processes. The analysis is done ‘from cradle-to-grave’, i.e. over the whole life cycle. LCA is essentially a comparative method: different systems fulfilling the same function (serving the same purpose) are compared on the basis of a ‘functional unit’ - a quantitative measure of this function or purpose. It is often believed that LCA can be used for judging the (relative) sustainability of product systems. This is only partly true, however, since LCA is restricted to the environmental part of the triad ‘environment/ecology - economy - social aspects (including intergenerational fairness)’ which constitutes sustainability. Standardized assessment tools for the second and the third part are still lacking, but Life Cycle Costing (LCC) seems to be a promising candidate for the economic part. Social Life Cycle Assessment still has to be developed on the basis of known social indicators.Method and Limitations LCA is most frequently used for the comparative assessment or optimization analysis of final products. Materials and chemicals are difficult to analyse from cradle-to-grave, since they are used in many, often innumerable product systems, which all would have to be studied in detail to give a complete LCA of a particular material or substance! This complete analysis of a material or chemical is evidently only possible in such cases where one main application exists. But even if one main application does exist, e.g. in the case of surfactants (chemicals) and detergents (final products), the latter may exist in a great abundance of compositions. Therefore, chemicals and materials are better analysed ‘from cradle-to-factory gate’, leaving the analysis of the final product(s), the use phase and the ‘end-of-life’ phases to specific, full LCAs.Conclusion A comparative assessment of production processes is possible, if the chemicals (the same is true for materials) produced by different methods have exactly the same properties. In this case, the downstream phases may be considered as a ‘black box’ and left out of the assessment. Such truncated LCAs can be used for environmental comparisons, but less so for the (environmental) optimization analysis of a specific chemical: the phases considered as ‘black box’ and left out may actually be the dominant ones. A sustainability assessment should be performed at the product level and contain the results of LCC and social assessments. Equal and consistent system boundaries will have to be used for these life cycle tools which only together can fulfil the aim of assessing the sustainability of product systems.     

Measurements of carbonyls in a 13-story building

BACKGROUND, AIM AND SCOPE: Formaldehyde and acetaldehyde are emitted by many mobile and stationary sources and secondary aldehydes are intermediates in the photo-oxidation of organic compounds in the atmosphere. These aldehydes are emitted indoors by many materials such as furniture, carpets, heating and cooling systems, an by smoking. Carbonyls, mainly formaldehyde and acetaldehyde, have been studied because of their adverse health effects. In addition, formaldehyde is a suspected carcinogen. Therefore, the concentrations of formaldehyde and acetaldehyde were determined to assess the inhalation exposure doses to carbonyls for people who work in a 13-story building and in order to evaluate the cancer hazard. METHODS: Carbonyl compounds in indoor and outdoor air were measured at a 13-story building located in Mexico City. The mezzanine, fifth and tenth floors, and the third level-parking garage were selected for sampling. Samples were collected in two sampling periods, the first from April 20 to 29, 1998 and the second from December 1 to 20, 1998. Carbonyls were sampled by means of DNHP-coated cartridges at a flow rate of 1 l min(-1) from 9:00 to 19:00 hours, during 2-hour time intervals and analyzed by HPLC with hours, during 2-hour time intervals and analyzed by HPLC with UV/VIS detection. RESULTS: Mean carbonyl concentrations were highest in the 3rd level-parking garage, with the formaldehyde concentration being the highest ranging from 108 to 418 microg m(-3). In working areas, the highest carbonyl arithmetic mean concentrations (AM) were observed on the 5th floor. Acetone and formaldehyde concentrations were highest in April ranging from 161 to 348 microg m(-3) (AM = 226) and from 157 to 270 microg m(-3) (AM = 221), respectively. Propionaldehyde and butyraldehyde were present in smaller concentrations ranging from 2 to 25 and 1 to 28 microg m(-3), respectively, considering all the samples. Mean indoor/outdoor ratios of carbonyls ranged from 1.8 to 9.6. A reduction of inhalation exposure doses of 41% and 45% was observed in the fifth floor air after the air conditioning systems had been repaired. Formaldehyde and acetaldehyde concentrations were higher in smoking environments. CONCLUSION: Indoor carbonyl concentrations were significantly greater than outdoor concentrations. Tobacco smoke seems to be the main indoor source of formaldehyde. After the air conditioning system was maintained and repaired (as was recommended), an important reduction in the emission of formaldehyde and acetaldehyde was achieved on all floors, except for the 3rd level parking garage, thereby reducing the inhalation exposure doses. RECOMMENDATION: The results obtained in this research demonstrated that maintenance of air conditioning systems must be carried out regularly in order to avoid possible adverse effects on health. Additionally, it is mandatory that isolated smoking areas, with air extraction systems, be installed in every public building.     

机械产品的绿色设计技术

本文通过对机械绿色产品的定义及内涵的描述,提出了机械产品绿色设计的基本方法和绿色设计中的主要内容及技术关键.     

Changes in Forest Use Value through Ecological Succession and Their Implications for Land Management in the Peruvian Amazon

Abstract:  Research on local use values of forests across an ecological succession informs land-use decisions and conservation planning. I evaluated use values of three age classes of secondary forest: fallow fields (<5 years old, $8.20/ha/year), young secondary forest (5–20 years old, $20.60/ha/year), and old secondary forest (>20 years old, $6.80/ha/year). I quantified daily forest product use and calculated use values in dollars per hectare per year for three communities in the northern Peruvian Amazon. I made three comparisons between forest types: number of useful species, value based on different use categories, and overall use values. Old secondary forest had the greatest number of total species present and species collected. Wood, food, and medicine were the three most valuable use categories. The value different families extracted from local forests varied enormously, but median forest values were lower for all forest types than potential gains from agricultural land use (e.g., coffee $167/ha/year). Values of different-aged stands on privately owned lands in two communities did not differ significantly, whereas in the third community, young secondary forest had a significantly greater value than other forest types. Old secondary forests were the most valuable source of wood products, and wood was the only use category in which there was any difference in the value of products extracted from different-aged forest stands. The value of all three forest types on open-access (nonprivate) lands was minimal (mean in each forest type, $0/ha/year). Local people can utilize the valuation results to develop land-use strategies that balance forest product use, agricultural productivity, and biodiversity conservation.