垃圾填埋二次污染的危害与防治

介绍了垃圾卫生填埋中二次污染的危害,指出垃圾卫生填埋场建设和填埋操作中为防止填埋释放物对周围环境的二次污染所应采取的防渗、收集、处理和利用等措施,探讨了在垃圾卫生填埋场建设和填埋操作中应注意的问题及应着重考虑的方面.     

The ecological effects of trichloroacetic acid in the environment

Trichloroacetic acid (TCAA) is a member of the family of compounds known as chloroacetic acids, which includes mono-, di- and trichloroacetic acid. The significant property these compounds share is that they are all phytotoxic. TCAA once was widely used as a potent herbicide. However, long after TCAA's use as a herbicide was discontinued, its presence is still detected in the environment in various compartments. Methods for quantifying TCAA in aqueous and solid samples are summarized. Concentrations in various environmental compartments are presented, with a discussion of the possible formation of TCAA through natural processes. Concentrations of TCAA found to be toxic to aquatic and terrestrial organisms in laboratory and field studies were compiled and used to estimate risk quotients for soil and surface waters. TCAA levels in most water bodies not directly affected by point sources appear to be well below toxicity levels for the most sensitive aquatic organisms. Given the phytotoxicity of TCAA, aquatic plants and phytoplankton would be the aquatic species to monitor for potential effects. Given the concentrations of TCAA measured in various soils, there appears to be a risk to terrestrial organisms. Soil uptake of TCAA by plants has been shown to be rapid. Also, combined uptake of TCAA from soil and directly from the atmosphere has been shown. Therefore, risk quotients derived from soil exposure may underestimate the risk TCAA poses to plants. Moreover, TCE and TCA have been shown to be taken up by plants and converted to TCAA, thus leading to an additional exposure route. Mono- and di-chloroacetic acids can co-occur with TCAA in the atmosphere and soil and are more phytotoxic than TCAA. The cumulative effects of TCAA and compounds with similar toxic effects found in air and soil must be considered in subsequent terrestrial ecosystem risk assessments.     

东涌工业污水处理站污泥处置方法的研究和探讨

本文通过番禺区东涌工业污水处理站污泥特性和污泥堆肥技术的研究,提出了污泥堆肥的可行性,并用之于实践,变废为宝,解决了污泥的处置问题.     

Management of an Agroecosystem

Agroecosystems (AESs) are autotrophic ecosystems managed by man. The goal of the management is to obtain the maximum possible amount of high-quality agricultural products while preserving agricultural resources, primarily the soils and biodiversity. The main components of the management of AES structures and functions, including primary and secondary biological production, the ratio between the energy flows in the plant–man and plant–livestock–man food chains, the efficiency of energy transfer in the plant–livestock link, and conservation of agricultural resources, are considered.     

The value of the environment – Is it a matter of approach?

This paper discusses why estimates of the benefits of reduced air pollution differ in accordance with the approach used. Estimates based on bottom-up studies of the damage costs related to air pollution usually turn out much lower than estimates based on assessments of the utility of reduced air pollution, obtained for instance by willingness to pay assessments. This is usually explained by the fact that the willingness to pay approach includes the utility aspect of non-market values, and for this reason, it is often preferred to the damage cost approach. This is, however, not the whole story. The paper shows why alternative approaches should not be considered as being in conflict, but rather as means to get supplementary information necessary to put a value on environmental quality. Information from bottom-up assessments of damage costs and from studies of the willingness to pay is used in a macroeconomic model to carry out an evaluation of the social costs of energy saving measures in Hungary.     

川西气田地层水回注选井选层研究

根据川西气田的实际情况,对致密砂岩层回注选井选层技术进行研究,初步建立了致密砂岩层回注选井选层技术,优选出川西气田1、2、3号等5个回注井区。目前,注水规模300m3/d,累计注水量达75 698.8m3,节约生产成本约200万元,且有效缓解了高浓度氯离子地层水外排带来的环保压力。现场回注试验表明:致密砂岩层回注高浓度氯离子地层水是可行的,回注选井选层技术具有现场推广应用价值。     

城市旅游综合体发展模式与对策研究

旅游综合体顺应了世界休闲业发展的潮流，它以旅游为主导，是一种全新的生产力形态。界定了城市旅游综合体的基本概念，归纳了城市旅游综合体的主要特征，探讨了城市旅游综合体形成的机制，认为旅游消费转型发展、地方特色文化传承、城市商业发展、旅游供给能力升级、政府的城市发展政策支持是城市旅游综合体形成的主要因素。依据城市旅游综合体发展的核心驱动功能不同，将城市旅游综合体的开发模式分为娱乐旅游综合体、休闲度假游综合体、会展旅游综合体和商业旅游综合体4种类型，在此基础上，提出了促进城市旅游综合体健康持续发展的对策。     

用二级模糊评判模型评价环境质量状况

用二级模糊评判模型评价区域环境质量状况,弥补了用一级模糊综合评判只可评价各点位环境质量状况的不足,是一种新的环境评价方法,评价结果与实际情况相符,效果良好,方法实用.     

Reproductive success increases with degree of kinship in cooperative coalitions of female red howler monkeys (Alouatta seniculus)

Evaluation of evolutionary mechanisms proposed to promote cooperative behavior depends on the relative influence of the behavior on the reproductive success of individuals, the reproductive success of the group in which they interact behaviorally, and the degree of gene correlation among cooperators. The genetic relationship within cooperative coalitions of female red howler monkeys was examined for three populations with different densities and growth rates. Patterns of gene correlation change within coalitions is documented using data from the mitochondrial and nuclear genomes, and long-term census monitoring. Differences in fecundity and infant survivorship within and between groups of unrelated (rˉ=0) and related (rˉ≥ 0.25) females are compared. Females that emigrate from their natal groups form coalitions with other migrant females. These coalitions attempt to establish a territory and, once successful in producing offspring, exclude other females from feeding resources. Females in these coalitions had different mtDNA haplotypes and a genetically estimated mean r of 0, supporting demographic data on emigration patterns indicating that these females rarely have the opportunity to form coalitions with kin. Patterns of recruitment and rate of matriline development within social groups supported behavioral data indicating that females actively attempt to promote their own matriline as breeders over that of other females, and that some matrilines are more successful at this than others. Mean r among females was significantly higher in coalitions established as social groups for several generations (rˉ=0.44). In these groups, females all shared the same mtDNA haplotype, and mtDNA haplotype divergence was significantly higher between than within groups. Females in coalitions with kin had significantly higher reproductive success than females in unrelated coalitions in all populations. This difference was not a function of coalition size, number of males, socionomic sex ratio, or primiparity, although anecdotal evidence suggests that allomothering may compensate for inept new mothers in related coalitions more often than in unrelated ones. Differences in territory quality could not be ruled out as a potential causal factor in the saturated populations, but were unlikely in the low-density, growing population. There were substantial differences among long-established coalitions in overall reproductive output in all three populations, and this was significantly correlated with the number of breeding females. Increase in coalition size was a function of both group age and the behavioral tolerance among females. Regardless of the underlying reasons for the patterns observed, reproductive success clearly increases with degree of gene correlation among females within cooperative coalitions, and coalitions that recruit more daughters produce more offspring. The nature of the cooperative relationship among group females directly influences both of these outcomes. This is associated with substantial genetic differentiation among social groups within populations, creating conditions in which genetic tendencies towards cooperative behavior can become tightly associated with group reproductive success. Received: 15 September 1999 / Revised: 27 April 2000 / Accepted: 27 May 2000     

Formation of Soluble Complexes of Metals with Humic Acid and Its Environmental Significance

In order to investigate the role of functional groups present in humic acid(s) (HA) during complex formation, water soluble complexes between HA isolated from soil and metals (Pb, Ca, As, Ni, Cr, Co, Cu, Cd, Fe, Mn, Mg and Zn) were prepared and subjected to infrared (IR) spectroscopy. the IR data revealed the involvement of the - OH group of humic acid in complex formation with all metals except copper and arsenic, whereas the - COOH group of HA was found to be the preferred site of binding for all the metals. the significance of findings in relation to detoxification of environmental pollutants is discussed in this paper.