Combined use of molecular biology taxonomy, Raman spectrometry, and ESEM imaging to study natural biofilms grown on filter materials at waterworks

DNA-based population analysis was applied in combination with Raman spectrometry and Environmental Scanning Electron Microscopy for the characterisation of natural biofilms from sand and activated carbon filters operated for a long term at a municipal waterworks. Whereas the molecular biology polymerase chain reaction combined with denaturing gradient gel electrophoresis approach provides a deeper insight into the bacterial biofilm diversities, Raman spectrometry analyses the chemical composition of the extracellular polymer substances (EPS), microorganisms embedded in EPS as well as other substances inside biofilm (inorganic compounds and humic substances). Microscopy images the spatial distribution of biofilms on the two different filter materials. In addition, bacterial bulk water populations were compared with biofilm consortia using the molecular fingerprint technique mentioned.Population analysis demonstrated the presence of more diverse bacterial species embedded in a matrix of EPS (polysaccharides, peptides, and nucleic acids) on the sand filter materials. In contrast to this, activated carbon granules were colonised by reduced numbers of bacterial species in biofilms. Besides α-, β-, and γ-Proteobacteria, a noticeable specific colonisation with Actinobacteria was found on activated carbon particles. Here, the reduced biofilm formation came along with a decreased EPS synthesis. The taxonomy profiles of the different biofilms revealed up to 60% similarity on the same filter materials and 32% similarity of different materials. Similarity of adherent communities from filter materials and bulk water populations from the filter effluent varied between 36% and 58% in sand filters and 6–40% in granular activated carbon filters.The biofilm investigation protocols are most crucial to subsequent acquisition of knowledge on biofilm dynamics and bacterial contributions to transformation or adsorption processes in waterworks facilities.     

Species composition and quantitative representation of fishes in biotopes with the riffle minnow <Emphasis Type="Italic">Alburnoides bipunctatus</Emphasis>

Species composition of fishes was studied in rivers (capture sites) inhabited by the riffle minnow. In some localities, this species proved to occupy a leading position in the ichthyofauna, being obviously dominant. In small rivers, 16 species were caught together with it, including seven species regularly occurring in catches. The relative abundance of riffle minnow showed a moderate positive correlation with that of the gudgeon (0.568) and a nonsignificant negative correlation (?0.399) with that of the bleak. It is probable that the population dynamics of riffle minnow are determined mainly by natural intraspecific mechanisms rather than by water quality, which has changed only slightly in the rivers studied.     

Challenges to liberalism: The case of Australian energy policy

This paper considers liberal and nationalist economic policy approaches to the ownership and development of Australian energy resources (oil, gas, coal and uranium). In the two decades prior to 1983, Australia pursued economic policies in relation to its energy resources which could broadly be described as ‘nationalist’. Governments of the day intervened in development decisions in an effort to enhance the ‘national interest’. From 1983, along with the deregulation of the Australian economy as a whole, policy relating to energy resources was liberalised. Development of energy reserves henceforth occurred according to the dictates of the market. This paper argues that recent Australian energy policy initiatives reflect an increase in nationalist influences and a retreat from the liberalisation agenda that dominated energy policy making in the 1980s and 1990s. Three examples are discussed where policy has been influenced by a nationalist framework: (1) the domestic gas reservation policy in Western Australia; (2) Australian government efforts to promote a ‘value adding’ nuclear processing industry and (3) Australian Labor Party policy giving preferential financial incentives for gas to liquids projects. The re-emergence of nationalism in Australia is occurring either because policy makers now favour it as a path to energy security or in some cases because they believe that appeals to nationalism will generate political support.     

Screening analysis of volatile organic contaminants in commercial inorganic coagulants used for drinking water treatment

A method for quality screening is suggested to detect volatile impurities in inorganic coagulants that are used for drinking water treatment. Static headspace gas chromatography with mass spectrometry detection (HS–GCMS) is sensitive and selective to detect volatiles in low concentrations. This study has discovered that volatile organic impurities are detectable in ferric and aluminium-based coagulants which are used for drinking water treatment. For ferric chloride, 2-propanol was detected at a level of 17–24 μg ml⁻¹, acetone at 0.7–1.7 μg ml⁻¹, 1,1,1-trichloroacetone at 0.02–0.04 μg ml⁻¹, trichloromethane at 0.01–0.02 μg ml⁻¹ and toluene at 0.01–0.12 μg ml⁻¹. For ferric chloride sulfate, acetone was detected at a level of 0.12 μg ml⁻¹, 1,1,1-trichloroacetone at 0.06–0.08 μg ml⁻¹, trichloromethane at 0.13–0.23 μg ml⁻¹, bromodichloromethane at 0.04–0.06 μg ml⁻¹ and dibromochloromethane at 0.04–0.05 μg ml⁻¹. For aluminium hydroxide chloride, only trichloromethane was detectable, but below the method detection limits (MDL). Although the concentrations of these impurities in commercial coagulants are low, this observation is important and should have impact on water industries for them to pay attention to the chemicals they are using for drinking water production.     

Comparing the impacts of hiking, skiing and horse riding on trail and vegetation in different types of forest

Nature-based tourism in protected areas has increased and diversified dramatically during the last decades. Different recreational activities have a range of impacts on natural environments. This paper reports results from a comparison of the impacts of hiking, cross-country skiing and horse riding on trail characteristics and vegetation in northern Finland. Widths and depths of existing trails, and vegetation on trails and in the neighbouring forests were monitored in two research sites during 2001 and 2002. Trail characteristics and vegetation were clearly related to the recreational activity, research site and forest type. Horse trails were as deep as hiking trails, even though the annual number of users was 150-fold higher on the hiking trails. Simultaneously, cross-country skiing had the least effect on trails due to the protective snow cover during winter. Hiking trail plots had little or no vegetation cover, horse riding trail plots had lower vegetation cover than forest plots, while skiing had no impact on total vegetation cover. On the other hand, on horse riding trails there were more forbs and grasses, many of which did not grow naturally in the forest. These species that were limited to riding trails may change the structure of adjacent plant communities in the long run. Therefore, the type of activities undertaken and the sensitivity of habitats to these activities should be a major consideration in the planning and management of nature-based tourism. Establishment of artificial structures, such as stairs, duckboards and trail cover, or complete closure of the site, may be the only way to protect the most sensitive or deteriorated sites.     

美国对石油天然气勘探开发中废物的环境监管

石油天然气勘探开发及生产过程中会产生大量的废物,对这些废物的管理目前受到各国高度的重视。文章介绍了美国石油和天然气勘探开发中废物的监管机构、监管要求和管理实践,以期对我国油气行业勘探开发废物的环境监管有所启示。     

尾气循环技术在国内顺酐装置的应用

顺酐生产过程排放的废气中含有大量未反应原料、副产物CO和挥发性有机物(VOC)等,对其进行处理使之达标排放,回收其中可利用的物质或能量有重要意义。吐哈石化厂顺酐装置采用CONSER公司工艺技术,新增部分尾气回收生产工艺路线,回收40%的尾气中的正丁烷,实现了蒸汽分阶利用,排放的废气中SO2、NOx、颗粒物等达到GB16297-1996《大气污染物综合排放标准》中二级标准。     

苏里格气田试气队伍节能减排工作现状及改进建议

苏里格气田试气队伍因涉及数家企业单位,节能减排工作有其特殊性和复杂性。通过调查试气过程中的排污状况,分析了其节能减排工作中出现的几个问题,如计量粗放、管理薄弱、措施简单等,提出了健全管理制度,完善计量系统,鼓励技术研究,加强自主创新,创建统一平台,依靠丙方监管等措施,以促进其节能减排工作健康有序地发展。     

烟道气脱硫脱硝一体化技术进展＊

烟道气中SO2、NOx往往同时存在,但是实际中脱SO2、脱NOx两个过程相互影响,妨碍了两种污染物质的脱除。联合脱硫脱硝技术是烟气治理的发展方向。系统介绍了利用催化剂、类水滑石复合氧化物、活性炭、固体废物、电子束、脉冲电晕等脱硫脱硝的一体化技术,分析了其脱除过程及相关反应原理。比较探讨了各种方法的特点、应用情况,并对各类技术的应用前景进行了展望。     

厌氧发酵沼气工程的工艺及存在的问题

利用厌氧消化技术处理畜禽养殖废水,制取清洁能源——沼气,在治理污染的同时变废为宝,减少温室气体的排放,从而实现国民经济的可持续性发展。本文概述了集约化畜禽养殖场废污水处理中采用的厌氧发酵工艺,以及厌氧发酵沼气工程中存在的问题。