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1.
苯酚是炼焦(油)、塑料、化工等行业生产过程中的主要污染物。随着经济的快速发展,各类含酚废水已经严重威胁着人类的生存环境。利用微生物处理含酚废水是一种经济有效且无二次污染的方法。本文主要研究了光合细菌-沼泽红假单胞菌降解含酚废水的动力学参数。实验结果表明,沼泽红假单胞菌对含酚废水具有很好的降解性能,正常状态下,该菌最大比生长速率μmax为8.00 mg/g.h,半速率常数Ks为247.92 mg/L,产率系数Y为5.88 mg/mg,内源呼吸系数Kd为0.29 d-1。  相似文献   

2.
小球藻降解苯酚的研究   总被引:1,自引:0,他引:1  
为利用藻类处理含酚废水,分离培养小球藻作为藻类种源,配置不同浓度苯酚水为受试水样,进行藻类对苯酚的降解实验研究,得出藻类对苯酚吸附降解的适宜浓度是200mg/l以下.所以可以利用藻类处理低浓度含酚水。  相似文献   

3.
高效苯酚降解菌PDB1的筛选及降解特性研究   总被引:1,自引:0,他引:1  
从一个焦化厂受污染土壤中分离获得一株具有高效降解苯酚能力的不动杆菌属细菌PDB1,以苯酚为唯一碳源和能源对该菌株降酚特性进行研究。结果表明:在初始苯酚浓度低于1 200 mg/L时,该菌株能够在60 h内完全降解苯酚;在更高苯酚浓度下,高浓度苯酚对菌株生长造成明显抑制,菌株降酚能力出现显著下降。对该菌株苯酚降解动力学过程进行模拟,苯酚降解符合基质抑制型的Haldane模型;当初始苯酚浓度低于144.56 mg/L时,苯酚比降解速率随苯酚浓度增大而增大;在苯酚浓度为144.56 mg/L时,得到最大比降解速率,苯酚浓度高于144.56 mg/L时,苯酚比降解速率逐渐下降。该菌株降解苯酚最适温度为25~40℃,p H为7.0~8.0,菌株具有良好的高盐分耐受性,能够耐受5%Na Cl浓度并取得良好降酚效果。  相似文献   

4.
Fenton试剂催化降解酚类化合物的研究   总被引:6,自引:0,他引:6  
研究了在Fenton试剂催化作用下,对氯苯酚、邻氯苯酚、2,4-二氯苯酚和对硝基酚的降解反应条件,计算在一定条件下的动力学一级反应的表面反应速率常数和活化能,测定催化降解前后摸扒含酚废水的COD值。在选定条件下,催化降解主大于96%,COD去除大于94%,为更有效地处理含酚废水寻求合适的催化体系提供依据。  相似文献   

5.
以苯酚为唯一碳源利用梯度富集培养,从湖北省孝昌县污水处理厂曝气池的活性污泥中分离筛选出一株高效苯酚降解菌株,经16S r DNA序列分析,初步鉴定菌株为Rhodococcus biphenylivorans,命名为Rhodococcus biphenylivorans sp.B403(嗜联苯红球菌B403).该菌株在含苯酚500 mg/L的无机盐培养基处理30 h后,其OD600达到最高0. 974,苯酚降解率达到98%.比较不同培养基的菌株生长曲线和降解曲线发现,在苯酚-LB-无机盐混合培养基中菌株稳定期生物量比LB培养基高出30%~40%,15 h降解苯酚效率达到99%以上,18 h内实现苯酚完全降解,苯酚降解效率最佳,显著高于目前已报道菌株.说明在其他有机碳源存在的条件下,更有利于嗜联苯红球菌B403生长.该菌株可用于含酚类污染物的有机废水处理及有机质丰富的酚类污染土壤修复.  相似文献   

6.
酚降解性活性污泥的固定化研究   总被引:2,自引:1,他引:2  
实验确定了以聚乙烯醇(PVA)为包埋剂固定化活性污泥的最佳条件,制备得到了固定化降解苯酚的活性污泥.最佳条件为:PVA质量浓度为100g/L,交联剂pH值为7.0.固定化后活性污泥性能得到明显改善,缩短或消除了活性污泥降解苯酚的延滞期,可在较短时间内达到高降解率,对于质量浓度为1500g/L的含酚废水,前5日的降解率可达98.3%.  相似文献   

7.
研究了采用液电等离子体降解含酚废水的模型物2,4-二硝基苯酚及液电等离子体降解含酚废水过程.研究发现,在16 kV下反应30 min,2,4-DNP基本被降解.废水经过液电等离子体降解后,形成等离子体酸类物质,其pH值降到3.30左右,电导率增加到300μS/cm.废水的初始电导率增加会抑制液电等离子体放电过程;其初始pH值在4.00左右时,降解率最高;空气流速对2,4-DNP降解的影响不大,鼓入大量空气可提高气液传质,利于酚类降解.  相似文献   

8.
研究了氯酚废水(100~800mg/L)在阳极为经氟树脂改性的β-PbO2,阴极为镍铬钛合金网上的电催化降解。考察了曝气、pH值、电流对氯酚降解效率的影响。结果表明,在氧气流量为0.05m^3/h、pH3.0、电流密度为0.7A时,氯酚的降解效率最好。该方法用于处理含酚浓度大、酸性高的废水,可以不经稀释或中和调节等预处理而直接处理,具有很好的应用前景。  相似文献   

9.
从某焦化厂处理废水的活性污泥中筛选到一株苯酚高效降解菌(Wust-C),该菌属革兰氏阴性菌.对Wust-C降解苯酚的特性进行试验研究.结果表明,在初始苯酚浓度为1 000 mg/L的试样中,培养24 h后,Wust-C对苯酚的降解率可达98%;初始苯酚浓度为300 mg/L试样中的苯酚可在8h内完全降解.采用海藻酸钠对菌体进行固定化后,Wust-C的降酚效率进一步得到提高.培养24 h后,固定化Wust-C对初始苯酚浓度为1 200 mg/L试样中的苯酚降解率达到100%,初始苯酚浓度为300 mg/L试样中的苯酚可在4h内完全降解.Wust-C的加入对混合菌群降解苯酚起到了促进作用.  相似文献   

10.
对臭氧-紫外光-超声波协同作用氧化降解模拟苯酚废水进行了实验研究,探讨不同因素对苯酚氧化降解效果的影响以及处理苯酚废水至最佳效果的能耗.结果表明,苯酚初始p H为9,臭氧进气量为0.6 m L/min,苯酚的初始浓度为140 mg/L,超声频率为34 k Hz,超声功率为300 W时处理效果最佳.反应4 h苯酚去除率达到99%,COD去除率达到97%,所需成本为0.33元/kg.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

17.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

18.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
1 Rise of studies on climate change's effects on biodiversity
Until the 1980s, climate change and biodiversity were studied as two independent disciplines for more than a century. In 1992, the Ecological Society of America's annual report named climate change, biodiversity, and the sustainable ecological system as the three major global environmental issues of the twenty-first century [1].  相似文献   

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