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51.
52.
液压介质的污染是液压元件过早磨损的主要原因。介绍了污染源产生的原因及污染颗粒的磨损机理,结合自己工作中的实例论述了液压介质清洁度对液压润滑系统的重要性。 相似文献
53.
54.
化学实验教学中的环保问题浅析 总被引:2,自引:0,他引:2
阐述了化学实验教学中存在的污染问题,分析了化学实验中污染的来源和污染特性,提出了消除或减轻化学实验性污染的必要性,并说明了实现化学实验绿色化的几种方法. 相似文献
55.
5种绿藻对几种常用抗生素的敏感性 总被引:10,自引:0,他引:10
屈建航 《大连轻工业学院学报》2004,23(2):111-113
考察莱茵衣藻、亚心形扁藻、四爿藻、微绿球藻和小球藻5种绿藻对几种常用抗生素的敏感性,结果表明,莱茵衣藻对卡那霉素、四环素敏感,敏感浓度(细胞致死浓度,下同)均为25μg/mL,对氯霉素敏感性次之,而对氨苄青霉素不敏感;亚心形扁藻和四爿藻对氯霉素敏感,敏感浓度均为25μg/mL,对四环素、卡那霉素和氨苄青霉素不表现敏感性;小球藻和微绿球藻对实验中的4种抗生素都不敏感。 相似文献
56.
结合实例说明,搞好清洁生产对氯化法钛白企业治理环境污染,提高企业的经济效益和今后长远发展起着举足轻重的作用和重要的指导意义. 相似文献
57.
David Gabriel Huub H. J. Cox Marc A. Deshusses 《Canadian Metallurgical Quarterly》2004,130(10):1110-1117
Until recently, biological treatment of odors in biofilters or biotrickling filters was thought to require a longer gas contact time than chemical scrubbing, hence bioreactors for air treatment required a larger footprint. This paper discusses the conversion of chemical scrubbers to biological trickling filters. Initially, research was conducted with a laboratory-scale biotrickling filter. An effective open-pore polyurethane packing material was identified and H2S biotreatment performance was quantified. Key technical issues in determining the general suitability of converting wet scrubbers to biotrickling filters were identified, and a generic ten-step conversion procedure was developed. Following the laboratory research, five full-scale chemical scrubbers treating odorous air at the Sanitation District of Orange County, Calif., were converted to biotrickling filters. The original airflow rate was maintained, resulting in a gas contact time as low as 1.6–3.1?s. The converted biotrickling filters demonstrated an excellent capability for treating high H2S concentrations to concentrations below regulatory limits. This study shows outstanding potential for converting chemical scrubbers to biotrickling filters at publicly owned treatment works. 相似文献
58.
Emissions from fossil fuel combustion containing various heavy metals such as molybdenum are of public concern due to their adverse effects on human health and the environment. In this study, thermodynamic analyses were applied to determine the potential of sorbent technology to control molybdenum emissions from combustion sources. The effectiveness of four sorbents (Ca, Fe, Mg and Na based) was assessed for a wide range of temperatures. The adverse effects of chlorine and sulfur were also examined. Ca and Na-based sorbents were identified to be effective. 相似文献
59.
Biofiltration, a process in which contaminated air is passed through a biologically active bed, can be used to remove volatile organic pollutants from air streams. While most biofilters rely on bacteria to degrade organic pollutants, biofilters utilizing a fungal biofilm have the potential to be an efficient and robust treatment alternative. In this study, two surfactants were evaluated for their ability to activate the spores of the fungus Exophiala lecanii-corni and reduce the start-up period typically observed in fungal vapor-phase bioreactors. Sodium dodecyl sulfate, an anionic surfactant, was found to inhibit growth of E. lecanii-corni. Polyoxyethylene sorbitan monolaurate (Tween 20), a nonionic surfactant, stimulated bud formation and enhanced toluene degradation in E. lecanii-corni cultures. Tween 20 was also found to enhance inoculum development by shortening the lag period during culture growth. However, when bioreactors were presoaked in medium containing Tween 20, washout of the fungal cells occurred during inoculation, inhibiting the initial fungal biofilm development. After a seven-day start-up period, no detrimental effects on reactor performance due to residual Tween 20 were observed, and toluene elimination capacities of up to 150?g/m3?h were achieved. 相似文献
60.
Nancy N. Sauer Deborah S. Ehler Brandy L. Duran 《Canadian Metallurgical Quarterly》2004,130(5):585-588
The applicability of water-soluble polymers as extractants for the remediation of heavy metal-contaminated soils has been explored using a lead-contaminated Superfund soil as a sample system. Polyethylenimine (PEI) was functionalized with bromo- or chloroacetic acid to give an aminocarboxylate chelating group, which effectively binds lead. The resulting polymer, PEIC, has extraction properties similar to the molecular chelator ethylenediaminetetraacetic acid. A series of studies was done to probe optimum conditions for lead extraction from soils obtained from the Cal-West Superfund site in New Mexico that contained approximately 10,000 ppm of Pb. In batch extraction experiments using polymer functionalized at two different levels, the polymers removed greater than 97% of the lead from the soils. Subsequent experiments demonstrated that the selective extraction of lead could be controlled by varying polymer functionalization levels. Concentration and regeneration of the polymers using ultrafiltration was also demonstrated. Release of lead from the polymer was accomplished by acidification to pH 1 with HCl. Subsequent ultrafiltration allowed recovery of the extractant polymer for reuse. 相似文献