Using the expert model PERPEST to translate measured and predicted pesticide exposure data into ecological risks

An important topic in the registration of pesticides and the interpretation of monitoring data is the estimation of the consequences of a certain concentration of a pesticide for the ecology of aquatic ecosystems. Solving these problems requires predictions of the expected response of the ecosystem to chemical stress. Up until now, a dominant approach to come up with such a prediction is the use of simulation models or safety factors. The disadvantage of the use of safety factors is a crude method that does not provide any insight into the concentration–response relationships at the ecosystem level. On the other hand, simulation models also have serious drawbacks like that they are often very complex, lack transparency, their implementation is expensive and there may be a compilation of errors, due to uncertainties in parameters and processes. In this paper, we present the expert model prediction of the ecological risks of pesticides (PERPEST) that overcomes these problems. It predicts the effects of a given concentration of a pesticide based on the outcome of already performed experiments using experimental ecosystems. This has the great advantage that the outcome is more realistic. The paper especially discusses how this model can be used to translate measured and predicted concentrations of pesticides into ecological risks, by taking data on measured and predicted concentrations of atrazine as an example. It is argued that this model can be of great use to evaluate the outcome of chemical monitoring programmes (e.g. performed in the light of the Water Framework Directive) and can even be used to evaluate the effects of mixtures.     

Effects of golden shiner (Notemigonuscrysoleucas ) nest association on host pumpkinseeds (Lepomisgibbosus ): evidence for a non-parasitic relationship

The reproductive success of male parental pumpkinseeds, Lepomisgibbosus, was studied in relation to the use of their nests by spawning golden shiners, Notemigonuscrysoleucas. The brood size of pumpkinseeds with and without golden shiner's young was compared in a field population. Mean egg and larval numbers of pumpkinseeds did not differ between broods with and without shiners, suggesting that shiners had no net effect on the fitness of host pumpkinseeds. In the laboratory, however, hatching success of pumpkinseed embryos was significantly lower with shiners than without. This difference was attributable to fungal infection. Against this fitness loss, the presence of shiner larvae reduced predation on pumpkinseed larvae in laboratory experiments. Thus, two counteracting mechanisms are proposed to account for no observed net effect on the host: (1) increased fungal infection on pumpkinseed embryos and (2) decreased predation on pumpkinseed young. Received: 10 January 1997 / Accepted after revision: 9 August 1997     

水平基因转移及其在污染修复中的应用

水平基因转移加速了部分生物体基因组的进化和革新;但随着基因改造生物的大量运用,由水平基因转移引起的生态安全问题越来越成为人们争论的焦点.由于大量异生污染物的产生,污染地区成为细菌水平基因转移的一个"热点"区域.为了实现污染地区的生物修复及强化难降解废水处理的效果,人为的制造和加快特定降解基因的水平转移被认为是解决这些问题的一个新思路.图2参57     

生物多样性与城市景观生态建设

论述了生物多样性在城市景观中的重要作用，生物多样的现代城市中的衰落以及城市生物多样性保护与景观生态建设的关系，提出应将生物多样性保护计划同城市景观生态建设结合起来。     

添加剂升温烧蚀法在制备新型介孔水环境净化材料中的应用

首次探索了一种破坏式造孔与有机复合相结合的新方法以制备介孔复合水环境净化材料,使最终产品成为一种具有广谱孔结构分布的复合环境材料。详细介绍了该方法的第二步工艺即添加剂升温烧蚀法,在优化后的最佳条件下,产品的孔径得到了进一步扩大,其中部分孔道直径可达至介孔级,同时材料的表面得到了进一步活化。经此步工艺后,所制备的中间产品染料吸附量是原材料的194倍,是酸洗刻蚀后产品的122倍;24h吸湿率是原材料的38倍,是酸洗刻蚀后产品的19倍。     

Speciation of heavy metals in estuarine sediments in the northeast of Brazil

An analytical procedure involving a three-step sequential extraction was used to determine the chemical association of heavy metals (Zn, Cr, Mn and Fe) with the major phases (exchangable, reducible and oxidizable) in samples from a fishpond of estuarine sediments. The pond is located in the Capibaribe River estuary, within the boundaries of the city of Recife, in the State of Pernambuco in the northeast of Brazil. The total metal content was determined as well. All metals were extracted from the residual fraction at a percentage greater than 50%.     

沉水植物综合利用的研究进展

概述了沉水植物在富营养化水体治理中的重要作用及对其资源化开发利用的必要性;重点论述了近年来国内外利用沉水植物净化富营养化水体的研究现状,并对沉水植物的资源化利用方式进行了探讨;展望了开发和利用沉水植物资源的前景和意义。     

浮水植物水处理简介

为了配合乡、镇发展,须考虑规划兴建大型污水处理厂,以免污水破坏环境;但过往颇多大型污水处理厂出现初投大、使用率低等现像,原因是建造配套市政地下管网涉及更大之投资和复杂的征地、施工等问题,难以配合发展速度解决,或因不明朗因素高估了乡镇的发展需要,种种原因往往导致急速发展的地区浪费国家资源。浮水植物生长迅速、吸收养份的能力特强,美国早在三十多年前应用於处理生活污水,唯因有引起臭味、蚊患等蔽端而未推广,经改良之后受到进一步重视。浮水植物水处理系统大多采用凤眼莲,系统拥有统建设规模弹性、投资小、能耗低和操作易等优点,可作为乡、镇污水处理的一个过渡性选择甚至最终方案考虑。     

渗滤系统处理北方城市生活污水微生物数量变化的研究

本文应用粉煤灰渗滤系统处理北方寒冷地区城市污水,结果细菌数量去除率在89.6%—99.9%之间,粪大肠菌群数量去除率在90%—99.9%之间,此方法成本低、效果好,适合北方中小城镇污水处理。     

辽河铁岭段3条支流底栖动物调查及水质评价

对辽河铁岭段3条支流清河、柴河和混河入水库前的河段,利用底栖动物需氧特性,以需氧有机体百分率指标,对3条支流的水环境质量状况进行了监测调查和评价。