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891.
真菌降解废气中邻-二甲苯试验研究 总被引:5,自引:2,他引:3
采用真菌降解废气中的邻-二甲苯,试验装置为真菌生物滤池.将滤池内填料分成3段,考察每一段的负荷能力、去除效率以及pH值、温度、湿度的变化特点等.邻-二甲苯的进气浓度为400~700mg·m-3,气量为0 25m3·h-1,停留时间为100s.试验结果表明,真菌能够有效地去除废气中的邻 二甲苯,总去除率达到90%以上.其中,从上到下各段的去除率分别为36 8%,28 6%和25 5%.生物滤池内产生CO2的浓度与邻 二甲苯的降解有密切关联,通过在线监测进出气中的CO2浓度变化,可以间接反映出生物滤池的运行状况和生物生长量.在本研究中,降解的邻二甲苯中的碳约74%转化成CO2.微生物鉴定结果表明,降解邻 二甲苯的微生物主要是青霉菌和诺卡氏菌. 相似文献
892.
曝气生物滤池内的自养反硝化作用 总被引:4,自引:0,他引:4
采用多孔介质——火山岩为载体的上向流曝气生物滤池(BAF),研究了限制供氧条件下,无有机碳源时反应器的硝化反硝化特性.结果表明,在 10~30℃范围内,20℃为临界点,低于20℃时,硝化速率缓慢;高于 20℃后,硝化速率加快.温度从 20℃升高到 30℃,硝化速率增长仅为10%,这一特性与悬浮生长反应器内温度对硝化速率的影响完全不同.此外,稳定运行的 BAF 内存在大量氮流失现象,分析认为,限制供氧和无有机碳源时,生物膜内发生了以 Anammox反应为主的自养反硝化作用,大量的氮以 N2的形式流失. 相似文献
893.
Improvements of nano-SiO2 on sludge/fly ash mortar 总被引:1,自引:0,他引:1
Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar. 相似文献
894.
Municipal solid waste incineration (MSWI) ash is rich in heavy metals and salts. The disposal of MSWI ash without proper treatment may cause serious environmental problems. Recently, the local cement industry in Taiwan has played an important role in the management of solid wastes because it can utilize various kinds of wastes as either fuels or raw materials. The objective of this study is to assess the possibility of MSWI ash reuse as a raw material for cement production. The ash was first washed with water and acid to remove the chlorides, which could cause serious corrosion in the cement kiln. Various amounts of pre-washed ash were added to replace the clay component of the raw materials for cement production. The allowable limits of chloride in the fly ash and bottom ash were found to be 1.75% and 3.50% respectively. The results indicate that cement production can be a feasible alternative for MSWI ash management. It is also evident that the addition of either fly ash or bottom ash did not have any effect on the compressive strength of the clinker. Cement products conformed to the Chinese National Standard (CNS) of Type II Portland cement with one exception, the setting time of the clinker was much longer. 相似文献
895.
Variations of metal distribution in sewage sludge composting 总被引:4,自引:0,他引:4
In the study, the variations of heavy metal distributions (of Cu, Mn, Pb, and Zn) during the sewage sludge composting process were investigated by sequential extraction procedures. The total content of Cu and Zn in the composted mixture increased after the composting process. Mn and Zn were mainly found in mobile fractions (exchangeable fraction (F1), carbonate fraction (F2), and Fe/Mn oxide fraction (F3)). Cu and Pb were strongly associated with the stable fractions (organic matter/sulfides fraction (F4) and residual fraction (F5)). These five metal fractions were used to calculate the metal mobility (bioavailability) in the sewage sludge and composted mixture. The mobility (bioavailability) of Mn, Pb, and Zn (but not Cu) increased during the composting process. The metal mobility in the composted mixture ranked in the following order: Mn>Zn>Pb>Cu. 相似文献
896.
897.
农业作为国民经济的基础,是生态文明的重要内容,其文明程度直接体现生态文明程度.生态文明建设给农业经营提出了更高的要求,也为农业生产的发展指明了方向.充分认识生态文明建设与农业生产的关系,加强农业相关人员的生态文明教育和农业环保法制建设,实施更加科学、文明的农业经营方式将对促进农业的可持续发展和生态文明建设发挥积极的作用. 相似文献
898.
固相微萃取(SPME)技术在水质监测中的应用 总被引:3,自引:0,他引:3
固相微萃取技术(SPME)作为一种样品前处理技术,具有方便、快捷、不使用有机溶剂、灵敏度高、价格低廉等优点,已被广泛地应用于环境样品的分析.本文综合评述了采用SPME法预处理环境水体中的有机物、无机离子等污染物的监测情况,并对SPME法在环境水质监测中的应用以及对国外的研究进展进行了展望. 相似文献
899.
Environmental contaminants with estrogenic activity have recently attracted attention due to their potential detrimental effects on the reproduction of human and wildlife. The aim of this study was to evaluate the use of endogenous glutathione and glutathione-related enzymes as biomarkers of exposure to landfill leachate effluent and bisphenol A (BPA) in the freshwater snail, Bellamya purificata. Following exposure to 1%, 5% and 10% landfill leachate effluent and 1, 10, 50 and 100mugl(-1) BPA for 0, 2, 7 and 15d, activities of glutathione S-transferase (GST), selenium-dependent glutathione peroxidase (SeGPx) and glutathione reductase (GR) and levels of total glutathione were measured in the gills and digestive glands of the snails. GST and total glutathione were the most sensitive parameters in both exposure scenarios. GST activities increased by about 80%, while total glutathione decreased to 70% and 80% in the gills and digestive glands, respectively. In contrast, SeGPx and GR activities remained at the same levels in all the treatment groups compared with those of controls. The results indicated that among glutathione and glutathione-related enzymes, GST activity and total glutathione level, which showed dose-dependent dynamics, could be used as biomarkers of aquatic ecosystems contaminated with landfill leachate. 相似文献
900.
重金属污染土壤接种丛枝菌根真菌对蚕豆毒性的影响 总被引:6,自引:1,他引:5
采用盆栽实验的方法,研究了重金属(包括Cu、Zn、Pb和Cd)复合污染和接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)Glomus mosseae对蚕豆(Vicia faba)生长及DNA损伤的影响.结果表明,虽然接种菌根真菌对蚕豆生物量的影响并不显著,但是却显著影响植物对重金属的吸收,接种菌根真菌对蚕豆吸收4种重金属元素的作用有差异.采用单细胞凝胶电泳(single cell gel electrophoresis,SCGE)法研究接种菌根真菌对蚕豆叶片的DNA损伤的影响,与重金属吸收的结果相吻合.结果表明,接种处理可显著增加蚕豆叶片的DNA损伤程度,这与接种处理可提高植物的重金属吸收相一致. 相似文献