降解丙烯酰胺的活性污泥培养及驯化研究

采用阶梯式驯化法，控制温度在18℃～24℃，pH在6—8，溶解氧在4—8mg／L，在容积为6L的驯化器中对活性污泥进行培养驯化。经过25d的培养之后，得到了稳定降解丙烯酰胺的活性污泥。驯化后的活性污泥SVI为85—132，COD去除率达70％。     

Optical and Chemical Methods of Metal Ash Analysis and Tin Recovery

‘Metal ash’ presents a waste disposal problem in most of the developing countries as the industries employ obsolete technologies. In this paper we describe analysis of tin ash, zinc ash and aluminium ash by means of optical methods, such as X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS), electron probe micro analysis (EPMA), scanning electron microscopy (SEM) and chemical methods. The results of tin ash obtained by XRD method matched well with the cassiterite, a naturally occurring mineral of tin. ICP-MS studies reveal the presence of a large number of tracer metals, which may cause pollution by tertiary dispersion and this aspect is discussed. Conversely, the data generated by chemical methods are limited. However, the methods are simple and cost-effective. Then, they can easily be adopted by low-budget industries. Simple and cost-effective process to recover tin from tin ash is described. It is based on heating tin ash with sodium cyanide to about 900°C to separate tin component from the metal ash. The process recovers good quality tin and offers a very high yield. The process can be scaled up to small pilot plant.     

17β-雌二醇在水体中的分布水平及去除方法研究现状

17β-雌二醇(E2)是一种常见的天然雌激素,普遍存在于各类水体环境,在水环境分布水平已经达到干扰鱼类内分泌系统的水平,被认为是作用最强烈、最具潜在影响的环境内分泌干扰物之一。文章重点介绍了17β-雌二醇在水体环境中的分布水平及去除方法,指出由于传统的污水处理工艺和净水工艺无法将其完全去除,增加深度处理工序已经迫在眉睫。针对E2的特点,现有水处理工艺宜增加能够生成强氧化剂.OH的工序。     

喷灌和沟灌方式对农田土壤NH3挥发的影响

研究了2016和2017年传统灌溉（沟灌）和节水灌溉（喷灌）方式氨（NH₃）挥发的季节年际动态变化特征及其影响因素.采用通气法进行原位监测,分析了土壤温度、体积含水量、铵态氮（NH₄⁺-N）、硝态氮（NO₃^--N）以及气温降水等因素对NH₃挥发的影响.结果表明,NH₃挥发速率的峰值出现在施用氮肥后1~2周,喷灌有效降低NH₃挥发峰值,喷灌和沟灌的NH₃挥发速率峰值在2016年分别为2.67kg/（hm²·d）和11.11kg/（hm²·d）,2017年分别为2.42kg/（hm²·d）和11.73kg/（hm²·d）;马铃薯生长季NH₃挥发存在明显的季节变化,挥发高峰主要发生在7~8月,追肥期高于基肥期.2016~2017年农田土壤NH₃累积挥发量均表现为喷灌<沟灌,与沟灌相比,喷灌分别减少58.15%和43.55%.NH₃挥发速率与土壤温度呈显著正相关（P<0.05）,与体积含水量、NH₄⁺-N、NO₃^--N浓度呈极显著正相关（P<0.01）.     

Effect of preparation methods on the performance of CuFe-SSZ-13 catalysts for selective catalytic reduction of NOx with NH3

CuFe-SSZ-13 catalyst showed excellent performance in the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) for diesel engine exhaust purification. To investigate the effect of preparation methods on NH₃-SCR performance, Fe was loaded into one-pot synthesized Cu-SSZ-13 catalysts through solid-state ion-exchange (SSIE), homogeneous deposition precipitation (HDP) and liquid ion-exchange (IE), respectively. Three CuFe-SSZ-13 catalysts showed similar SO₂ resistance, which was better than that of Cu-SSZ-13. The improvement was attributed to the protection of Fe species. Hydrothermal stability of three CuFe-SSZ-13 catalysts was significantly different, which was attributed to the state of active species caused by different preparation methods. Compared with the other two catalysts, more active species existed inside the zeolite pores of CuFe-SSZ-13_SSIE. During hydrothermal aging, the aggregation of these active species in the pores caused the collapse of catalyst structure, ultimately leading to the deactivation of CuFe-SSZ-13_SSIE. In contrast, Fe species was dispersed better on the surface over CuFe-SSZ-13_IE, enhancing the hydrothermal stability of catalysts. Consequently, Fe loading effectively improved the resistance of SO₂ and H₂O over Cu-SSZ-13. For CuFe-SSZ-13, large amounts of active species located inside the zeolite pores are not beneficial for the hydrothermal stability.     

Indigenous Systems of Forest Classification: Understanding Land Use Patterns and the Role of NTFPs in Shifting Cultivators’ Subsistence Economies

This article discusses the system of classification of forest types used by the Pwo Karen in Thung Yai Naresuan Wildlife Sanctuary in western Thailand and the role of nontimber forest products (NTFPs), focusing on wild food plants, in Karen livelihoods. The article argues that the Pwo Karen have two methods of forest classification, closely related to their swidden farming practices. The first is used for forest land that has been, or can be, swiddened, and classifies forest types according to growth conditions. The second system is used for land that is not suitable for cultivation and looks at soil properties and slope. The article estimates the relative importance of each forest type in what concerns the collection of wild food plants. A total of 134 wild food plant species were recorded in December 2004. They account for some 80–90% of the amount of edible plants consumed by the Pwo Karen, and have a base value of Baht 11,505 per year, comparable to the cash incomes of many households. The article argues that the Pwo Karen reliance on NTFPs has influenced their land-use and forest management practices. However, by restricting the length of the fallow period, the Thai government has caused ecological changes that are challenging the ability of the Karen to remain subsistence oriented. By ignoring shifting cultivators’ dependence on such products, the involvement of governments in forest management, especially through restrictions imposed on swidden farming practices, is likely to have a considerable impact on the livelihood strategies of these communities.     

An Assessment of the Valuation Methods Used to Calculate the Index of Sustainable Economic Welfare (ISEW), Genuine Progress Indicator (GPI), and Sustainable Net Benefit Index (SNBI)

For some time now, ecological economists have been putting forward a ‘threshold hypothesis’ – the notion that when macroeconomic systems expand beyond a certain size, the additional cost of growth exceeds the flow of additional benefits. In order to support their belief, ecological economists have developed a number of similar indexes to measure and compare the benefits and costs of growth (e.g., the Index of Sustainable Economic Welfare and the Genuine Progress Indicator). In virtually every instance where an index of this type has been calculated for a particular country, the movement of the index appears to reinforce the existence of the threshold hypothesis. Of late, a number of observers have expressed concerns about whether these alternative indexes reflect concrete reality or the prejudices of ecological economists. In view of these concerns, this paper closely examines the valuation methods used in the calculation the Index of Sustainable Economic Welfare, the Genuine Progress Indicator, and the Sustainable Net Benefit Index. It is argued that a consistent and more robust set of valuation techniques is required in order for these alternative indexes to gain broad acceptability.*Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Estimation of the maximal population frequency of “alien” biotypes taking into account a priori data

A method is described for calculating the probability that the percentage of alien biotypes is higher than a specified threshold (e.g., 5%) in a population in which a certain number of alien biotypes has been found preliminarily. The method is based on the Bayesian approach; it assumes that the researcher has preliminary (a priori) information on the frequency of these biotypes. This a priori information makes it possible to estimate the aforementioned probability more accurately than is possible with the use of the standard binomial estimation. The method is illustrated by the results of the estimation of cultivar purity in batches of stock and foundation seeds of spring barley with the use of protein markers.Translated from Ekologiya, No. 2, 2005, pp. 106–109.Original Russian Text Copyright © 2005 by Zhivotovsky, Pomortsev, Lyalina, Kalabushkin, Pukhalskii.     

应急预案编制基本操作程序及方法

应急预案编制涉及行业领域专业技术、应急管理知识、工作进度和质量管控等多方面内容,是一项专业性、系统性很强的工作。为向公众普及有关工作程序和方法,笔者结合实际工作经验提炼出应急预案编制工作的核心思想,引入项目管理的思路,提出一种面向对象、以实践应用为导向的工作模式。本文有详细的步骤展示,提供相应的文本样式,并对常见工作方法、技巧和失误进行归纳分析。研究结果提供一种可行的思路参考,对于应急预案编制设计、评审等人员具有一定参考和科普传播价值。