共查询到20条相似文献,搜索用时 142 毫秒
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生物泡沫对污水处理厂的运行和出水水质都会产生不良影响。研究了由乙酸钙不动杆菌产生的生物泡沫的生物相特性和温度、pH值、溶解氧、泥龄这些环境因子变化对微生物的影响,通过改变环境因子可预防生物泡沫的产生。并介绍了福州市祥坂污水处理厂由乙酸钙不动杆菌引起的生物泡沫的处理方法。生产运行证明,控制生物泡沫除了常用的物理和化学方法之外,改变工艺运行方式也是非常有效的措施。 相似文献
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活性污泥污水处理厂生物泡沫产生机理及控制 总被引:7,自引:0,他引:7
在城市污水处理厂活性污泥法工艺的运行中,生物泡沫与浮渣(简称生物浮沫)和活性污泥膨胀一样.是困扰运行管理的重要问题。该文对国外生物泡沫的产生现状、成因、影响因素、丝状微生物研究和控制方法等方面进行了综述,提供国内相关研究参考。 相似文献
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采用A~2/O-MBR为主体工艺运行的污水处理厂,生化池中生物泡沫的产生是一个普遍存在的问题。尽管生物泡沫对生化池的出水水质并没有太大影响,但对污水厂的日常运行管理和MBR膜污染都有很大影响。通过采用顶部进水的方式对一个实际应用A~2/O-MBR为主体工艺的污水厂的生化池各个工艺段进行连通,加上去方格化的池型优化设计,实现了对生物泡沫的有效收集和处理,减少了大量消泡剂的使用。 相似文献
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刘哲 《中国石油和化工标准与质量》2013,(12):248
研究了在污水厂日常运行中过程中泡沫对其影响的具体表现,并对泡沫产生的原因进行了分析。初步探究了影响活性污泥法中泡沫产生的因素,进一步探讨了消除泡沫的常用方法。 相似文献
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Aspects of loss prevention and consideration of risks in the chemical industry . When dealing with questions of safety and loss prevention, a distinction must be made between the terms danger, safety, source of danger, and risk. Relevant sources of danger are tabulated. The risk in breakdowns is discussed at length in terms of the factors incidence rate and damaging effect with the aid of recent literature. Access to incidence rates is provided by logic diagrams which are of great value on a qualitative basis for loss prevention. The basic requirements for a quantitative treatment are considered and the problems arising with quantitative results are discussed. Loss prevention can be achieved by reducing incidence rates and/or damaging effects. 相似文献
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A M O'Donnell 《Archivos latinoamericanos de nutrición》1988,38(3):685-704
Nutritional and dietary recommendations are given for infants, preschool and school children in Latin America, based on known and prevailing nutritional deficiencies, and on the prevention of degenerative diseases in adulthood. Special emphasis is placed on dietary iron and zinc deficiencies, as well as on the prevention of obesity and atherosclerosis, diseases which are seriously affecting medium and high socioeconomic levels of the Latin American population. 相似文献
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化学危险品是具有爆炸、易燃、毒害、感染、腐蚀、放射性等危险特性,在运输、储存、生产、经营、使用和处置中,容易造成人身伤亡、财产损毁或环境污染而需要特别防护的物品。文章介绍了易燃固体、自燃物品及遇水放出易燃气体的物质、易燃液体、危险气体、爆炸品、毒性物质和感染性物质、氧化性物质和有机过氧化物六类化学危险品的基本特性,说明了其火灾预防措施,并概述了它们在发生灾害事故时的处置措施或灭火方法。 相似文献
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探讨了炼化企业在航煤产品中常常出现的机械杂质、悬浮物等固体颗粒的鉴别方法、种类判定,以及影响航煤洁净度指标杂质的产生原因、影响成度和防御措施。 相似文献
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T. E. Nicholson 《Journal of the American Ceramic Society》1932,15(7):386-386
This paper deals with a peculiar discoloration of a typical terra cotta glaze. The method of solving the problem is outlined, and conclusions are reached which point out methods of prevention of similar defects. 相似文献
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姚昕 《中国生物制品学杂志》2013,26(3):433-436
肠道病毒71型(Enterovirus 71,EV71)是手足口病(Hand,foot and mouth disease,HFMD)的主要病原体,属于肠道小RNA病毒,这类病毒的基因组由脆性平链RNA组成,易断裂,有较高的突变性。在混合感染中会发生同型不同株不同亚型,或同属不同型间的基因交换形成新的重组病毒,EV71也具有重组特性。新形成的重组病毒可能导致其生物学特性和致病性的改变,进而影响疾病的防控。本文就EV71病毒基因重组及可能引发的防控问题进行综述。 相似文献
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Saba Haq Shadan Ali Ramzi Mohammad Fazlul H. Sarkar 《International journal of molecular sciences》2012,13(10):12556-12572
Cancer epidemiology and prevention is one of the most well studied fields today. The more we can understand about the incidence and pathogenesis of this disease, the better we will be able to prevent it. Effective prevention strategies can decrease the mortality rate of cancer significantly; this is why it is important to delineate the underlying causes. It has been well recognized that genetic mutations, sporadic or hereditary, may lead to increased chance of tumorigenesis. Detecting genetic mutations can lead to the identification of high-risk individuals with hereditary cancer syndromes, which may assist in devising prevention strategies. Further, environmental factors are known to play important roles in epidemiology and suggest prevention tools that could be implemented to reduce cancer incidence and subsequent cancer-associated morbidity and mortality. Chemoprevention has been tried in colon cancer and is finding new advancements in other carcinomas as well. Out of many environmental cancer preventive agents, the most notable developments are the identification of the role of vitamins E, vitamin D and folic acid. Increased consumption of these vitamins has shown to be inversely correlated with cancer risk. This review will highlight important aspects of cancer epidemiology in the most aggressive carcinomas of the gastrointestinal system focusing on colorectal adenocarcinoma and pancreatic adenocarcinoma. Additionally, some of the well-known and evolving aspects of epidemiology of colorectal and pancreatic cancer along with current and new prevention strategies will also be reviewed. 相似文献