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101.
Toxicity of some organic and inorganic chemicals to microorganisms is an important consideration in assessingtheir environmental impact against their economic benefits.Microorganisms play an important role in several environmentalprocesses, both natural and engineered. Some organic and inorganics at toxic levels have been detected in industrial discharges resulting in plant upsets and discharge permit violations. In addition to this, even though in some cases the effluent wastewater does not exceed the discharge limits,the results of toxicity tests show potential toxicity. Toxicityknowledge of effluents can benefit treatment plant operators inoptimising plant operation, setting pre-treatment standards, and protecting receiving water quality and in establishing sewer discharge permits to safeguard the plant. In the Turkish regulations only toxicity dilution factor (TDF) with fish is part of the toxicity monitoring program of permissible wastewater discharge. In various countries, laboratory studiesinvolving the use of different organisms and protocol for toxicity assessment was conducted involving a number of discharges.In this study, it was aimed to investigate the acute toxicity of textile and metal industry wastewaters by traditional and enrichment toxicity tests and emphasize the importance of toxicity tests in wastewater discharge regulations. The enrichment toxicity tests are novel applications and give anidea whether there is potential toxicity or growth limiting and stimulation conditions. Different organisms were used suchas bacteria (Floc and Coliform bacteria) algae (Chlorella sp.), fish (Lepistes sp.) and protozoan (Vorticella sp.) to represent four tropic levels. The textile industry results showed acute toxicity for at least one organism in 8 out of 23 effluent samples. Acute toxicity for at least two organisms in 7 out of 23 effluent sampling was observed for the metal industry. The toxicity test results were assessed with chemical analyses such as COD, BOD, color and heavy metals. It was observed that the toxicity of the effluents could not be explained by using physicochemical analyses in 5 cases for metal and 4 cases for the textile industries. The results clearly showed that the useof bioassay tests produce additional information about the toxicity potential of industrial discharges and effluents.  相似文献   
102.
Abstract: Informally gathered species lists are a potential source of data for conservation biology, but most remain unused because of questions of reliability and statistical issues. We applied two alternative analytical methods (contingency tests and occupancy modeling) to a 35‐year data set (1973–2007) to test hypotheses about local bird extinction. We compiled data from bird lists collected by expert amateurs and professional scientists in a 2‐km2 fragment of lowland tropical forest in coastal Ecuador. We tested the effects of the following on local extinction: trophic level, sociality, foraging specialization, light tolerance, geographical range area, and biogeographic source. First we assessed extinction on the basis of the number of years in which a species was not detected on the site and used contingency tests with each factor to compare the frequency of expected and observed extinction events among different species categories. Then we defined four multiyear periods that reflected different stages of deforestation and isolation of the study site and used occupancy modeling to test extinction hypotheses singly and in combination. Both types of analyses supported the biogeographic source hypothesis and the species‐range hypothesis as causes of extinction; however, occupancy modeling indicated the model incorporating all factors except foraging specialization best fit the data.  相似文献   
103.
While it is generally known that interpersonal trust facilitates individual functioning, few studies have examined the role of specific features of the interpersonal trust network — individual, dyadic, third‐party, and network‐level features — on individual performance. We adopt a multilevel perspective of interpersonal trust to examine how individuals' performance is not only predicted by their individual‐level centrality in the interpersonal trust network but also moderated, at the network level, by the overall centralized nature of that network. Further, we examine whether mutual trust relationships at the dyadic level, as well as shared trust ties to common third parties, can predict individuals' performance. We test our hypotheses with 206 members in 15 professional networking groups and find that interpersonal trust operates at multiple levels to predict members' performance in terms of generating income from business referrals. These findings provide theoretical and practical implications on how interpersonal trust relationships operate and can be managed for performance gains. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
104.
安全工程专业课程体系优化研究   总被引:1,自引:0,他引:1  
基于安徽理工大学安全工程专业课程体系,提出"2+2"培养模式下"安全技术与管理"方向课程体系存在的问题及其原因,包括课程内容的重复性,课程设置未突出特性培养和课程设置未突出时代性等。提出从按照全国工程教育专业认证指导思想整改,避免课程知识体系过多重复,通才教育的基础上突出自身专业特点以及按照国家的方针政策来指引方向等四个方面阐述了解决课程体系存在的相关问题,优化课程体系,来体现安全工程专业人才培养的国际性、科学性、市场性和全面性等特点。  相似文献   
105.
专业认证背景下的安全工程专业特色教育研究与实践   总被引:1,自引:0,他引:1  
回顾专业认证在国内外的发展情况,简单介绍《安全工程专业本科教育认证标准》的内容和安全工程专业认证近年来在国内的发展情况。根据南华大学的实际情况,提出在专业认证的背景下,针对行业特点,实行分方向设置课程和从事教学活动。南华大学安全工程专业主要依托"核"行业背景,下设核安全、建筑安全和化工安全3个方向;3个专业方向分别设置了不同的基础课、专业基础课、专业课和选修课;课程设置符合《安全工程专业本科教育认证标准》的要求,并严格按照教学计划开展教学。实践证明,该项教学改革取得明显成效,该校安全工程专业近两年的就业率和考研率都居于全校前列,并且就业单位具有明显的行业特点。  相似文献   
106.
侯娟  邵嘉慧  何义亮 《环境科学》2010,31(6):1518-1524
以Aldrich 腐殖酸溶液为水样,研究比较了溶液环境(pH值、离子强度和钙离子)对荷电改性再生纤维素超滤膜和传统中性未改性再生纤维素超滤膜过滤过程的影响.结果表明, ①pH值主要通过质子化作用影响荷电膜以及腐殖酸分子的荷电量,进而影响荷电超滤过程.溶液pH值从7.5下降到3.5时,荷电超滤膜对腐殖酸的截留率从92%减少到79%,超滤4 h时,膜通量下降从26%增加到36%.②离子强度的改变是通过影响腐殖酸分子的物化性质和静电屏蔽作用来影响超滤过程的.当溶液离子强度为0、 3和100 mmol/L时,初始截留率依次降低,分别为92%、 87%和48%,超滤4 h时,荷电超滤膜的通量下降依次增加,分别为26%、 35%和63%.③Ca2+浓度的影响,需要综合考虑静电屏蔽作用、Ca2+的架桥作用以及滤饼层的压实性等各方面的影响.④pH值、离子强度和钙离子对中性超滤膜过滤行为的影响趋势与荷电超滤膜相似,但其影响程度有着较大的差别.研究结果对荷电超滤膜技术在实际应用中选择合适环境条件提供了参考.  相似文献   
107.
中药制药废水成分复杂,水质变化大,可生化性较好。采用ABR+复合好氧反应器+BAF工艺处理中药废水,运行结果表明:COD、BOD5、NH3-N、及SS平均去除率分别达95%、98.7%、73.3%和93.5%,出水水质达GB8978-1996《污水综合排放标准》一级标准。  相似文献   
108.
基于生态系统对宝鸡传统乡村旅游新模式进行了探究。首先通过分析宝鸡部分传统乡村旅游的现状,对宝鸡传统乡村旅游现状进行了介绍。提出宝鸡开展民俗旅游的一些不足之处;其次说明基于生态系统理念,对宝鸡传统乡村旅游和生态环境的促进作用;然后提出观光主题公园与乡村民俗旅游的结合,可以更好地促进乡村生态环境和乡村旅游的可持续性发展,更能充分开发旅游资源,丰富旅游项目,促进乡村环境和乡村经济的双重发展,使宝鸡传统乡村旅游新模式得到发展。  相似文献   
109.
大都市传统工业区休闲旅游转型发展研究综述   总被引:1,自引:0,他引:1  
传统工业区休闲旅游转型是大都市城市功能和产业空间优化的关键问题,目前该方面研究尚未形成系统性的理论研究体系.论文梳理了国内外相关研究成果,从休闲旅游转型趋势,转型价值,转型空间演化,转型要素,转型模式,转型效应和转型策略等方面进行了研究内容和研究结果的总结,评述了国内外在研究时间,研究内容,研究方法上的差异.最后认为现有研究缺乏从人地关系视角对传统工业区转型背景,要素,动力,空间演化的系统分析,今后应针对中国大都市发展特点,重点关注传统工业区休闲旅游转型发展模式,转型过程,机制以及综合效应等方面的研究,从理论性和可操作性上指导我国城市传统工业区的休闲旅游改造.  相似文献   
110.
微污染水处理技术研究进展   总被引:8,自引:0,他引:8  
饮用水水源微污染日益严重,给传统的饮用水处理工艺提出新的挑战.本文阐述了饮用水处理技术的研究进展,包括:强化传统处理工艺、预处理技术、深度处理技术及应用,并给出了各种技术的优缺点.  相似文献   
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