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1.
几株光合细菌的表型特征及DNA-NDA同源性分析   总被引:4,自引:1,他引:4  
对5株新分离的光合细菌从形态、生理生化及DNA-DNA同源性等方面进行了研究.结果表明,菌株8与深红红螺菌(Phodospirillumrubrum)的模式菌株ATCC11170的DNA-DNA同源性为97%,菌株37与沼泽红假单胞菌(Rhodopseudomonaspalustris)的模式菌株ATCC17001的DNA-DNA同源性为80%;菌株55与球形红杆菌(Rhodobactersphaeroides)的模式菌株ATCC17023的DNA-DNA同源性为71%;菌株40和52分别为另外两个DNA同源群.根据各菌株形态、生理生化等表型特征以及DNAG+Cmol%和DNA-DNA同源性分析结果,确定了几株光合细菌的分类地位.  相似文献   

2.
乳状液膜法萃取氨基酸的研究   总被引:7,自引:0,他引:7  
徐占林  严忠 《环境化学》1997,16(4):369-373
本文以TOMAC为载体,ECA4360J为表面活性剂,内外相Cl^-浓度梯度为推动力,研究了L-苯丙氨酸在乳状液膜体系中的传输,并对影响液膜萃取的各种因素进行了系统的阐述,确定了此体系的最佳膜相组成的实验条件,实现了L-苯丙氨酸的提取和浓缩。  相似文献   

3.
旅游业焦点     
旅游业焦点常设栏目,报道可持续旅游领域的发展,和联合国环境规划署旅游计划的活动承载能力KenChamberlain,前理事长,太平洋亚洲旅行协会(PATA),2FordCourt,Chetnole,Sherborne,DorsetDT96NX,UK摘...  相似文献   

4.
TCC&TCS对废水生物处理中原生动物的毒性研究   总被引:2,自引:0,他引:2  
本文研究了TCC(2,2,4’—Trichlorocarbanilide)、TCS(2,2,4’—Trichloro-2-hydroxydiphenyl)对废水生物处理中的原生动物的急性毒性作用,结果表明:(1)TCC对原生动物的48hLC50为25000μg/L,TCS48hLC50为23000μg/L;TCC&TCS浓度与原生动物的半数致死时间LT50呈明显的负相关。(2)TCC&TCS对原生动物的最大无作用浓度分别为15mg/L和11mg/L,这提示污染源排放的废水到达曝气池时TCC&TCS的含量应低于15mg/L和11mg/L。  相似文献   

5.
本文研究了TCC(2,2,4’-Tricholrocarbanilide)、TCS(2,2,4’-Trichloro-2-hydroxydiphenyl)对废水生物处理中的原生动物的急性毒性作用,结果表明:(1)TCC对原生动物的48h为LC50为25000μg/L,TCS 48h LC50为23000μg/L;TCC&TCS浓度与原生动物的半数致死时间LT50呈明显的负相关。(2)TCC&TCS  相似文献   

6.
电解制备高效聚合铝的溶液化学因素   总被引:9,自引:0,他引:9  
曲久辉  路光杰 《环境化学》1997,16(6):522-527
采用电化学方法合成聚合氯化铝,通过在线有效控制电解过程的关键参数,可以年鉴轩出高碱化度,高Alb含量的PAC液体产品,本文研究了PAC电合成的重要溶液化学因素,如电解液的性质、浓度、组成、pH、离子迁移,形态转化等,从而提出了制备设定浓度和碱化度的PAC的最佳溶液化学条件,并证明溶液化学因素与电量参数之间具有必然联系。  相似文献   

7.
发根农杆菌转化青蒿影响因素的研究   总被引:7,自引:0,他引:7  
对叶盘法转化过程中各种影响因素进行研究.结果表明:发根农杆菌种类、基本培养基和青蒿株系对转化率有明显影响,而培养基pH在5.2~5.8对转化率没有明显影响;发根农杆菌ATCC15834的转化率最高;基本培养基中MS效果最好;青蒿株系025对发根农杆菌最敏感;处于对数生长期的发根农杆菌(D660nm=0.75)稀释5倍后用来转化效果最好;幼嫩的叶片的转化率比成熟叶片高;向共培养培养基中加入乙酰丁香酮等酚类物质对转化没有促进作用.在最适的转化条件下,发根农杆菌ATCC15834对青蒿株系025的转化率可达到100%.PCR检测证明,青蒿发根基因组中含有发根农杆菌Ri质粒TDNA上的rolC片段.  相似文献   

8.
活必炭纤维的表面结构及其吸附模式   总被引:2,自引:0,他引:2  
陈宏健  张静 《环境化学》1999,18(3):238-243
迄今的吸附模式,Henry定律、Langmuir模型、BET模型、D-R方程、D-A方程都分别适用于不同的表面结构。对于活性炭纤维(ACF)这种特殊的炭吸附材料适用于哪种吸附模型,未见有文献专题论述。本论文在对ACF材料进行了大量表面结构研究的基础上,对ACF的表面结构与颗粒活性炭(GAC)的表面进行了对比,并尝试性地对适用于ACF的吸附模式进行了计算和比较,得到了一些有价值的结论。  相似文献   

9.
SO2和O3动态胁迫烟草致病的暴露试验   总被引:1,自引:0,他引:1  
SO_2和O_3动态胁迫烟草致病的暴露试验陈锦云,兰志斌,苏珍山,曾军,王阳青(福建龙岩地区烟科所龙岩364000)关键词S)_2和O_3;烟草;气候斑点病,动态胁迫暴露THEDYNAMICSTRESSEXPOSURETESTONTOBACCOBLADE...  相似文献   

10.
白光月  王玉洁 《环境化学》1994,13(4):323-327
用乙基纤维素作膜材将三辛胺(简称TOA)微胶囊化,用于萃取酸性水溶液中的Cr2O7^2-离子。通过搅拌法萃取实验表明,TOA被微胶囊化后对铬离子仍具有较高的萃取速度,实验测定渗透系数为6.78×10^-6m/min,并能有效地防止乳化现象。将微胶囊制备成填充柱对Cr2O7^2-进行萃取实验。对外相水的流速、微胶囊粒径、柱的重复使用次数与萃取容量的关系进行了研究。当粒径为100-200μm,流速为3  相似文献   

11.
气相色谱法测定工业废水中联苯与菲   总被引:3,自引:0,他引:3  
文章研究了一种新的测定废水中联苯及菲含量的方法,该方法采用气相色谱薄涂柱,对联苯与菲进行了有效的分离与测定。该方法具有固定液用量少,柱温低,分离效果好,分析速度快等特点,利用该对废水样进行了测定,取得了满意的结果。  相似文献   

12.
催化氧化法处理对硝基酚钠生产废水的研究   总被引:3,自引:0,他引:3  
研究了催化氧化法处理对硝基酚钠生产废水的工艺参数,COD去除率可达90%,探讨了从酚钠母注人中盐析酚的条件,回收量为15.86Kg酚钠/m^3废液,提出了综合治理酚钠废水的工艺流程。  相似文献   

13.
本研究以锌镀层退底废液中锌配备顺收为例探讨从盐酸体系中分离酸-金属的工艺特点,选取了高效又价廉的国产萃取剂(N-235)和反萃剂(生石灰),建立了新的回收处理工艺路线,中试结果证明此工艺在技术上和设备上是可行的。  相似文献   

14.
Effluent originating from distilleries contain large amount of dark brown coloured wastewater called molasses spent wash (MSW). This MSW is the unwanted residual liquid waste to dispose because of low pH, high temperature, dark brown colour, high ash content, unpleasant odour and high percentage of organic and inorganic matter. Dark brown colour of MSW is due to the presence of melanoidin pigment. It reduces sunlight penetration in rivers and lakes which in turn decrease both photosynthetic activity and dissolved oxygen concentration affecting aquatic life. So the disposal of this effluent is one of the critical environmental issues. A number of treatment processes have been employed for the distillery waste management. This review paper present an overview of the pollution problems caused by melanoidin and the technologies employed globally for its removal.  相似文献   

15.
反渗透(Reverse Osmosis,RO)因出水水质好、运行成本低等优势常用于垃圾渗滤液的处理,但产生的RO浓缩液具有COD高、色度高、盐分高、难降解等特点,其处理存在效果差、能耗和成本均较高等问题.本工作采用氧化钌/氧化铱涂层电极(RuO2/IrO2-Ti)的钛网为阳极,以304不锈钢电极为阴极,设计制作了6通道的电化学反应器,通过电化学氧化处理RO浓缩液,研究考查了电流密度、循环流速、比电极面积等参数对COD去除效果的影响,分析了电化学氧化去除难降解有机物并同时脱盐的过程机理与能耗.结果表明,在电流密度32.89 mA·cm-2,循环流速0.46 cm·s-1,比电极面积65.10 m2·m-3的条件下,电化学氧化处理RO浓缩液3 h,COD去除率可达68.0%,TOC去除率可达40.6%,脱盐率可达72.1%,去除单位质量COD能耗仅为常规的板状电极电化学反应器的25.5%.本工作可为垃圾渗滤液RO浓缩液的预处理提供新思路.  相似文献   

16.
Centralized collection and disposal is an integral component of waste management strategies for many solid and liquid wastes, and carbon capture and storage is currently being considered for gaseous waste. In this paper we show how collective waste disposal systems introduce essential changes in the design of optimal environmental policy. Absent collective disposal, an optimal environmental policy imposes relatively stringent regulations on polluters in regions where local environmental damage functions are “high”; however, under collective waste disposal, the optimal environmental policy level increases monotonically over distance from the disposal site, and this is true irrespective of the degree of spatial heterogeneity in local environmental damage functions. We characterize the optimal spatial pattern of environmental policy levels under collective waste disposal and identify optimal membership size for waste disposal networks comprised of homogeneous producers.  相似文献   

17.
Increased care about the environment is currently evidenced by governmental, industrial, and consumer concern for ozone depletion, solid and liquid waste disposal, and pollutants. This concern has led to an increase in marketing of the “environmentally friendly” aspects of products. In the past, fly ash was generally released into the atmosphere, but pollution control equipment mandated in recent decades now requires that it is captured prior to release. In order to upgrade expansive soils as construction materials, fly ash, which is a waste material, has been selected and successfully used for stabilizing expansive clays in the Thrace region. The strength characteristics of the stabilized soils were measured. Depending upon the soil type, the effective fly ash content for improving the engineering properties of the soil varied between 8% and 12%. Using fly ash in roadwork projects will help the environment reducing the deposited amounts.  相似文献   

18.
The black soldier fly (BSF), Hermetia illucens, has been considered impressive as a saprophagous insect, for its high ability to convert organic waste to insect protein and oil. Hence, it has been regarded by the municipal administration that BSF might be used as a medium to deal with food waste. However, food waste in China has been characterized as having a high salt content, oily, and very spicy, which usually renders them unsuitable for animal feeding. In order to assess the technological reliability for BSF conversion of food waste, the tolerance of BSF for pH values, pungency, and NaCl in food were investigated in this case. Results indicated that strong acidity (pH = 3) was not good for the development of BSF, demonstrating less body weight and eclosion failure. In contrast, strong basicity (pH = 11) seemed to be beneficial for larval development with high biomass, and there is no difference in pupation, eclosion, larval biomass, and livability for BSF for pH values between 5 and 11. With regards to salinity, liner correlations were observed; the salinity strength increased along with the extension of the larval phase, but body weight, pupation rate, emerging rate, and livability were still consistent under 6% density of salinity. Influence of pungency on BSF larvae has not yet been found. In conclusion, BSF showed a high tolerance to pH value, pungency, and salinity in foodstuffs. Hence, it is expected that food waste from common environments might have a lesser possibility to cause negative effects on BSF development, which could be good news for BSF conversion technology. As for the process design, the conclusion suggested that food waste optimum for BSF is expected to be alkaline and low-salt, which would be helpful to improve the efficiency and harvest. © 2018 Science Press. All rights reserved.  相似文献   

19.
In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe–Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate.  相似文献   

20.
The awareness of the problem of the scarcity of water of high quality has strongly changed the approach of wastewater treatment. Currently, there is an increasing need for the beneficial reuse of treated wastewater and to recover valuable products and energy from the wastewater. Because microbiological treatment methods are, only to a limited part, able to satisfy these needs, the role and significance of physical/chemical processes in wastewater treatment are gaining more and more interest. The specific future role and aim of the various physical/chemical treatment processes can be categorized in five groups: improvement of the performance of microbiological treatment processes, achievement of the high quality required for reuse of the effluent, recovery of valuable components and energy from the wastewater for beneficial reuse, desalination of brackish water and seawater, and treatment of concentrated liquid or solid waste residues produced in a wastewater treatment process. Development of more environmentally sustainable wastewater treatment chains in which physical/chemical processes play a crucial role, also requires application of process control and modeling strategies. This is briefly introduced by the elaboration of treatment scenarios for three specific wastewaters.  相似文献   

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