利用行道绿化树叶片监测大气中SO_2污染的实验研究

本文通过分析植物叶片中含硫量探索了能否利用行道绿化叶树片来监测大气SO_2中污染的可行性。经希点采样分析证实所用的大叶黄杨栾树和黄桷树叶片均能吸收大气中 OS_2,其中以大叶黄杨吸收 SO_2量较大为8.05mg/g 干叶,可作常规监测用绿化树种     

利用行道绿化树叶片监测大气中SO_2污染的实验研究

本文通过分析植物叶片中含硫量探索了能否利用行道绿化叶树片来监测大气SO_2中污染的可行性.经希点采样分析证实所用的大叶黄杨栾树和黄桷树叶片均能吸收大气中OS_2,其中以大叶黄杨吸收SO_2量较大为8.05mg/g干叶,可作常规监测用绿化树种     

离子色谱测定大气降尘中的阴离子

大气自然沉积物亦称降尘。通常以专用玻璃降尘缸(保持300—500毫升水),采样器在3—20米高度范围内,在自然沉积条件下,以一个月为一采样周期进行采样。对降尘中的非水溶性及水溶性降沉量、用重量法测定,其值以:吨/平方公里·月表示。降尘所吸附或凝聚大气中的SO_2、NO_2含量常用比色法进行测定,其检测限分别为:SO_2—0.025mg/m~3、NO_2—0.04mg/m~3。降尘中以无机盐形成存在的阴离子(如SO_4~(2-)、     

遵义市汇川O_3、NO_2和SO_2变化特征分析

根据2015年1月—2017年12月间监测数据,分析了遵义市汇川大气中O_3、SO_2和NO_2浓度变化特征。结果表明,3年间SO_2污染最轻,NO_2次之,O_3污染较重;NO_2与SO_2浓度冬春季要显著高于夏秋季,O_3浓度表现为夏高冬低。夜间建筑施工及渣土车排放对NO_2浓度影响较大,社会生活燃煤排放对冬春大气中SO_2的贡献较大。相关性研究表明,不同天气下各污染物与相对湿度均呈负相关性,多云和晴天NO_2和SO_2浓度与风速、气温呈显著负相关性,而与O_3浓度呈正相关性。     

湿式除尘器的应用研究

新疆油田公司供热公司为提高除尘效率,减少SO_2排放量,将多管除尘器改造为湿式除尘器,介绍了湿式除尘器的结构和除尘原理。针对存在的问题,通过改进溢流箱结构解决了水位控制问题,烟气含尘量和SO_2排放量均达到GB 13271—2001《锅炉大气污染物排放标准》。介绍了利用纯碱、电石渣、锅炉的冲渣水与除尘器流出的冲灰水混合这三种烟气脱硫方法,其中,锅炉的冲渣水与除尘器流出的冲灰水混合的烟气脱硫方法综合效果最好。     

济南市大气中SO_2浓度变化特征研究

为研究城区近地面SO_2浓度变化特征,于2016年在山东大学对济南城市大气中SO_2浓度进行了连续监测。结果表明,济南城区SO_2年均浓度为0.049 mg/m3。SO_2存在明显的季节变化规律,浓度最高值出现在冬季1月,最低值出现在7月。SO_2在采暖季表现出明显的双峰型日变化,在非采暖季显示出单峰型日变化,这归因于非采暖季SO_2排放量远低于采暖季。风向、风速与SO_2扩散和输送密切相关,偏东方向,风速越大,SO_2浓度越高;其他方向,风速越大SO_2清除效果越好。     

草带护田防风蚀效应观测

农田与草场相间的带状垦殖效果是:草带植被20厘米高度内的立枯草平均170.5万株/公顷,防风效能平均值为4.5—5.4％,草带经施肥培育后,每公顷产草量提高77.2％,每6.67公顷的载畜量提高77％。护田草带不仅对干旱地区农业开发的环境治理与保护起到良好作用,同时也是培育改良草场,建设高效草库伦的新途径和新措施。     

浅析燃煤电厂超低排放改造策略

抚顺石化热电厂为自备燃煤电厂,新厂区3台锅炉均为高温高压煤粉炉。目前SO_2、NO_X烟尘的排放都无法满足《煤电节能减排升级与改造行动计划(2014—2020年)》的要求,通过对热电厂新厂区3台460t/h燃煤锅烟气进行超低排放改造,每年NO_X排放量可削减1 372t,SO_2的排放量削减594.6t,烟尘的排放量削减228t。排放烟气中NO_X50mg/Nm~3,SO235mg/Nm~3,烟尘10mg/Nm~3,达到上述国家要求。     

我国部分地区大气污染现状及其分布特征

收集2014—2016年我国部分地区环保部常规监测的6项大气污染物浓度,重点分析了我国东北、华北、华东、华中、西部地区经济快速发展城市空气污染的状况及分布特征。结果表明:除O_3外,其余污染物浓度均下降,SO_2二级达标率持续上升。各污染物区域性分布显著,北方比南方污染重。东部O_3污染严重;PM_(10)、CO浓度在华北地区最高;SO_2浓度在东北、华北最高;PM_(2.5)、NO_2浓度在华中、华北最高。华北地区大气污染严重,华东PM及SO_2污染最轻。     

用声强测量法确定声功率

测量的目的是在电动机和泵系统中确定由马达和泵分别发出的声功率。 电动机、泵和试验条件的说明 测量时采用洛赫有限公司异步电动机,其功率为20瓩,转速为1470转/分。此电动机置于100×67×75厘米油箱的顶部。连用丹福斯VPA20型泵的工作压力为180巴,有七个活塞,其容量为20厘米~3/转。因此泵的脉动次数为7×1470/60=171.5次/秒。     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

BIOLOGICAL INDICATORS AND BIOLOGICAL EFFECTS OF ESTUARINE/COASTAL POLLUTION1

ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Journalists' views of advertiser pressures on agricultural news

All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.     

Definition Procedures Have Little Effect on Performance of Environmental Classifications of Streams and Rivers

Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

Effect of Light on Biodegradation of Estrone, 17β‐Estradiol,and 17α‐Ethinylestradiol in Stream Sediment

Biodegradation of [A‐ring ¹⁴C] Estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) to ¹⁴CO₂ was investigated under light and dark conditions in microcosms containing epilithon or sediment collected from Boulder Creek, Colorado. Mineralization of the estrogen A‐ring was observed in all sediment treatments, but not epilithon treatments. No difference in net mineralization between light and dark treatments was observed for ¹⁴C‐E2. Net mineralization of ¹⁴C‐E1 and ¹⁴C‐EE2 was enhanced in light treatments. Extents of ¹⁴CO₂ accumulation and rates of mineralization were significantly greater for E2 than E1 under dark conditions, but were comparable under light conditions. These results indicate substantial differences in the uptake and metabolism of E1 and E2 in the environment and suggest biorecalcitrance of E1 relative to E2 in light‐limited environments. The extent of ¹⁴CO₂ accumulation and rate of mineralization for EE2 in dark treatments were less than half of that observed for E2 and generally lower than for E1, consistent with previous reports of EE2 biorecalcitrance. However, ¹⁴CO₂ accumulation and rates of mineralization were comparable for EE2, E2, and E1 under light conditions. These results indicate photoactivation and/or phototransformation/photodegradation processes can substantially enhance heterotrophic biodegradation of estrogens in sunlit environments and may play an important role in estrogen transport and attenuation.     

Bioremediation of Soils by Plant–Microbe Systems

Abstract

Sustainable ecosystems can be designed to eliminate environmental toxins and reduce pathogen loads through the direct and indirect consequences of plant and microbial activities. We present an approach to the bioremediation of disturbed environments, focusing on petroleum hydrocarbon (PHC) contaminants. Treatment consists of incorporating a plant-based amendment to enhance ecosystem productivity and physiochemical degradation followed by the establishment of plants to serve as oxidizers and foundations for microbial communities. Promising amendments for widespread use are entire plants of the water fern Azolla and seed meal of Brassica napus (rapeseed). An inexpensive byproduct from the manufacture of biodiesel and lubricants, rapeseed meal is high in nitrogen (6% wt/wt), stimulates >100-fold increases in populations of resident Streptomyces species, and suppresses fungal infection of roots subsequently cultivated in the amended soil. Synergistic enzymatic and chemical activities of plant and microbial metabolism in root zones transform and degrade soil contaminants. Emphasis is given to mechanisms that enable PHC functionalization via reactive molecular species.     

Provincial development plans in Zimbabwe: an analysis of their content,structure and methodology

Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.