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排序方式: 共有233条查询结果,搜索用时 15 毫秒
1.
The ability of indigenous microorganisms to degrade benzene, toluene, ethylbenzene and xylenes (BTEX) in laboratory scale flow-through aquifer columns was tested separately with hydrogen peroxide (110 mg/l) and nitrate (330 mg/l as NO3) amendments to air-saturated influent nutrient solution. The continuous removal of individual components from all columns relative to the sterile controls provided evidence for biodegradation. In the presence of hydrogen peroxide, the indigeneous microorganisms degraded benzene and toluene (> 95%), meta- plus para-xylene (80%) and ortho-xylene (70%). Nitrate addition resulted in 90% removal of toluene and 25% removal of ortho-xylene. However, benzene, ethylbenzene, meta- and para-xylene concentrations were not significantly reduced after 42 days of operation. Following this experiment, low dissolved oxygen (< 1 mg/l) conditions were initiated with the nitrate-amended column influent in order to mimic contaminated groundwater conditions distal from a nutrient injection well. Toluene continued to be effectively degraded (> 90%), and more than 25% of the benzene, 40% of the ethylbenzene, 50% of the meta- plus para-xylenes and 60% of the ortho-xylene were removed after several months of operation.  相似文献   
2.
During the day, there are considerable variations in the climatic factors prevailing in these regions. This is especially so during the 24-hour daily cycle of the long, hot and dry summer (mid-May to midOctober). Such climatic conditions have had a considerable impact on the daily living pattern of family life in the same season, particularly in the urban areas. During the same 24-hour cycle, they have compelled the inhabitants to shift their living activities both vertically in section and horizontally in plan; they do this in pursuit of more acceptable, if not, desirable internal thermal environmental ambience.  相似文献   
3.
ABSTRACT: In a screening of South African indigenous food plants for antioxidant activity by testing for inhibition of lipid peroxidation, the "potherbs" Amaranthus sp., Sisymbrium thellungii , and Urtica dioica had very high activity. This activity was greatest in the boiled extract of Amaranthus sp. and the boilet and aqueous extracts of Sisymbrium thellungii and Urtica dioica. The activity in the aqueous extract of Nasturtium aquatica was lost by boiling. High activity was also obtained with the teas Galium aparine and Aspalathus linearis (Rooibos) and with the tuber Colocasia esculenta.  相似文献   
4.
粤北某市"土法炼砷"土壤中化学砷污染的研究   总被引:1,自引:0,他引:1  
张昆峰  宋卫锋  钟宜航 《广东化工》2006,33(12):76-77,88
粤北某市“土法炼砷”造成的砷污染,严重破坏了当地生态环境,而且砷还会进入河流或地下水,严重威胁了当地及北江下游的饮用水安全和生态安全。本文对“土法炼砷”遗址现场进行调查取样,并对砷污染的特点进行了分析。  相似文献   
5.
Abstract

This article introduces a case study undertaken in the indigenous Penan community of Long Lamai, Upper Baram, Sarawak, Malaysia. In this community, there is concern about the negative image other cultural groups hold of the Penan. This case study explores co-design as a means to invite community members, together with a designer, to explore the identity that they would like to present to people outside the community. In preparing for an exhibition to challenge perceptions, it turned out to be important to embrace the culture of the community to facilitate self-expression, introducing new concepts such as technological interventions and design probes to stimulate reflection and creativity. However, it was indigenous material culture, when actively and encouragingly supported by the designer, that had a key role in developing the co-design and, with it, empathic understanding between designer and community.  相似文献   
6.
微生物在废水处理中的应用进展   总被引:3,自引:0,他引:3  
污水处理主要分为生化法和物理化学法两类,生化法具有投资少,操作方便,时间短等优点,而且能有效地减轻,甚至没有二次污染,高效回收有用物质。文中综述了微生物在含重金属离子废水、啤酒废水、染料废水、含油废水、核工业废水、抗生素工业废水等废水处理中的应用情况。  相似文献   
7.
Technologies for ballast water treatment: a review   总被引:1,自引:0,他引:1  
Invasive aquatic species discharged through ballast water is one of the most serious problems posed nowadays in the marine environment. This review paper summarizes the available technologies applied for ballast water treatment. These technologies can be either port‐based or ship‐based, with the latter being easier to implement. Special emphasis was given to onboard treatment methods, which can be categorized as physical separation, mechanical or chemical methods. The efficiency of the methods, as well as the capacity of application and the target microorganisms were compiled and are presented in this review. Copyright © 2009 Society of Chemical Industry  相似文献   
8.
Regional planning has long sought to manage places that extend across political boundaries. The international trend to decentralize governance and promote co-management of protected areas is consistent with emerging collaborative spatial planning theory (Healey, 1997, 1999, 2006), which suggests that through dialogue, parties assert multiple cultural perspectives, share knowledge, and forge shared landscape values as the basis of decisions. As a form of collaborative spatial planning, co-management specifies shared resource management power between national government and one or more local or indigenous communities. Both approaches assume decentralized governance systems. Although critics fault collaborative planning for glossing over historical and cultural contexts, and for ignoring power in decision making, few case studies ask why partners participate or how specific decentralized governance institutions affect plan implementation. This paper draws from a study of co-management at Mount Pulag National Park, the Philippines—a shared indigenous cultural landscape that was to be managed by a board representing multiple local, indigenous, and national jurisdictions. Tracing road decisions by two municipal partners, the paper summarizes how and why major stakeholders adopted and then circumvented protective policies by building duplicative road projects across fragile forests. In this context of changing indigenous rights, the same decentralization laws that enabled co-management also rewarded competition and strategic behavior that weakened the collaborative and fragmented the shared landscape. The case demonstrates the need to interrogate, rather than assume the benefits of decentralized governance and to study why stakeholders participate before relying on voluntary collaboration to manage regional landscapes. The initial version of this paper was presented to the 2006 annual meetings of the Association of Collegiate Schools of Planning, Fort Worth, Texas.  相似文献   
9.
结合靖安油田五里湾-区油藏高盐低渗特点,对其内源微生物进行了普查和分析,结果表明内源微生物类型和数量具有多样化的特点。以五里湾-区油井采出液为数活对象,在初步筛选营养成分的基础上,确定了碳源、氮源、磷源及其大致浓度,采用PB、最陡爬坡和响应面实验方法,以微生物生长和代谢为筛选条件,对影响微生物生长效果的因素进行了优化和评价,得到了最佳激活体系配方。该激活体系能够高效地激活该油藏中的内源微生物,并显著降低发酵液的表面张力,表明高盐低渗的五里湾-区油藏具有较大的内源微生物驱油提高原油采收率潜力。  相似文献   
10.
大港孔店油田本源微生物代谢产物监测分析   总被引:1,自引:1,他引:0  
应用放射性同位素示踪剂技术研究了大港孔店北二断块水动力学关系,结果表明该区块注水井和采油井之间具有紧密的水动力学连通关系。在本源微生物驱油试验阶段,对试验区微生物及其代谢物在地层中的分布状况进行了3年连续监测,表明本源菌激活期间菌数增加102~105倍,原油部分氧化,使得低分子脂肪酸(乙酸盐,甲酸盐,丁酸盐等)含量约增加10~100倍,碳酸氢盐从0·4~0·6g/L增加到0·7~1·8g/L,产生的生物表面活性剂使地层水平均表面张力降低至48~33·3mN/m,地层水相对石蜡平均界面张力降至25~13·7mN/m,产生的生物多糖代谢物使地层水平均粘度增至0·76mPa·s,最高达0·83mPa·s。这些变化改变了油层物理化学和生态环境,改善了原油流动性,尤其是水动力学连通关系最好的井地层水组成的改变和增油降水效果最为明显。试验区监测结果表明,微生物及代谢物随注入水主流动方向运移,生物表面活性剂和低分子脂肪酸及生物聚合物的作用是提高原油采收率的主要机理。  相似文献   
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