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41.
用微宇宙法研究稀土元素在富营养化水体中的归趋   总被引:1,自引:0,他引:1  
尹大超  戴乐美 《环境化学》1998,17(3):《环境化学》-1998年17卷3期-250--25页-《环境化学》-1998年17卷3期-250--25页
本文利用静态实验室水生微宇宙的方法研究了轻、中、重三类五种稀土混合物(La,Ce,Sm,Gd,Y)在富营养水体、底泥、浮萍、大型蚤、螺蛳和金鱼中的分布和富集。结果表明,稀土在水生微宇宙各组分中的分布和积累的趋势为轻稀土>中稀土>重稀土。稀土元素在水体中6h后基本趋于平衡,其大部分为底泥所吸附;不同生物对稀土的分布和富集存在着较大的差异,其趋势为浮萍>大型蚤>螺蛳>金鱼。  相似文献   
42.
The extensive use of antibiotics has been a worldwide environmental issue.In this study the fate of oxytetracycline (OTC),under photoirradiation,was investigated.The results showed that OTC photolysis followed first order model kinetics.Direct photolysis rate was found to be dependent on the initial OTC concentration,with k value ranging from 0.0075 to 0.0141 min~(-1),in the OTC concentration from 40 to 10 mg/L.OTC photolysis was highly pH-dependent and strongly enhanced at a high pH value,with a k value...  相似文献   
43.
以太湖地区两种典型的水稻土(乌泥土和白土)为供试土壤,在盆栽条件下种植多年生黑麦草,并配制不同pH值的模拟酸雨浇灌。通过多次刈割鲜草,研究模拟酸雨对土壤-植物系统中铜的化学行为的影响。结果表明:对植物体内铜含量的影响是模拟酸雨和“稀释效应”两种影响综合作用的结果。试验初期,表现为处理黑麦草体内铜含量低于对照;随收割茬次的增加,表现出随处理pH的降低,黑麦草体内铜含量的增加,且对缓冲能力弱的白土影响强度大于缓冲能力较强的乌泥土;对土壤pH有明显影响,随模拟酸雨作用时间增长,土壤pH下降,其降幅随处理pH的降低而增大;模拟酸雨主要影响交换态铜,表现为随处理pH的降低交换态铜的分配系数增高,在处理pH=3.0时影响到碳酸盐结合态铜,只有强酸化条件下(处理pH=2.0)才影响到铁锰氧化物结合态铜,对有机物结合态及残渣态铜几乎无影响。  相似文献   
44.
雷州半岛旱地砖红壤非点源氮、磷淋溶损失模拟研究   总被引:2,自引:0,他引:2  
大量施用化学肥料所引起的养分淋失和环境污染正逐渐受到人们的重视。通过土柱模拟氮、磷素养分淋溶试验.研究了不同施肥处理下砖红壤氮、磷素淋溶损失特点。试验结果表明,随着尿素用量的增加,渗漏水中NH4^+-N质量浓度和TN淋失量也相应增加,而NO3^--N的质量浓度变化幅度较大,渗漏水中氮素淋失形态主要是以NO3^--N为主。由于土壤磷素很难移动,所以TP累积淋失量非常少,氮、磷肥混施对非点源氮、磷素的淋失都有影响,其中过量磷肥配合尿素施用可以增加土壤中NH4^+-N、NO3^- -N、TN的淋失程度。  相似文献   
45.
The characterization of microbial communities of different depth sediment samples was examined by a culture-independent method and compared with physicochemical parameters, those are organic matter (OM), total nitrogen (TN), total phosphorus (TP), pH and redox potential (Eh). Total genomic DNA was extracted from samples derived from different depths. After they were amplified with the GC-341 f/907r primer sets of partial bacterial 16S rRNA genes, the products were separated by denaturing gradient gel electrophoresis (DGGE). The profile of DGGE fingerprints of different depth sediment samples revealed that the community structure remained relatively stable along the entire 45 cm sediment core, however, principal-component analysis of DGGE patterns revealed that at greater sediment depths, successional shifts in community structure were evident. The principle coordinates analysis suggested that the bacterial communities along the sediment core could be separated into two groups, which were located 0-20 cm and 21-45 cm, respectively. The sequencing dominant bands demonstrated that the major phylogenetic groups identified by DGGE belonged to Bacillus, Bacterium, Brevibacillus, Exiguobacterium, γ-Proteobacterium, Acinetobacter sp. and some uncultured or unidentified bacteria. The results indicated the existence of highly diverse bacterial community in the lake sediment core.  相似文献   
46.
电磁处理水实验平台建设与研究   总被引:3,自引:0,他引:3  
通过对国内外磁处理水技术发展的调研工作,自行组建了一套可调节电源额定电压、电源频率、电场强度、磁化流速、磁作用时间的利用高梯度磁场处理工业水的实验平台,用该平台对炼铁厂循环冷却水进行了模拟处理实验,实验结果分析表明,该实验技术可以用来对磁作用机理作深入分析,并优化系统工艺参数.  相似文献   
47.
高梯度磁处理对炼铁厂冷却水浊度的影响研究   总被引:1,自引:0,他引:1  
通过实验研究了外加高梯度磁场对炼铁厂冷却水作用的影响,结果表明,在适宜的磁场强度和磁作用时间下,该法可有效地降低冷却水的浊度.  相似文献   
48.
金鱼藻与铜绿微囊藻共生情况下的化感作用   总被引:17,自引:2,他引:15  
研究了金鱼藻(Ceratophfllum demersum)和铜绿微囊藻(Microcystis aeruginosa)共生时二者之间的相互作用.通过追踪测定铜绿微囊藻的藻细胞密度、叶绿素a浓度、藻胆蛋白含量、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量,研究了金鱼藻对铜绿微囊藻的化感作用机制,以及铜绿微囊藻对金鱼藻生长的胁迫.结果表明,金鱼藻对铜绿微囊藻有明显的抑制作用,作用96 h后藻细胞完全死亡;排除营养和光的竞争影响,认为抑制作用主要是由化感作用引起的.培养过程中,铜绿微囊藻叶绿索a和藻胆蛋白(包括藻蓝蛋白、别藻蓝蛋白和藻红蛋白)都有不同程度的损伤;作用末期,藻蓝蛋白的损伤程度最大,叶绿素a次之.藻细胞SOD活性以及MDA含量均呈先升高后降低的趋势.铜绿微囊藻对金鱼藻也有一定胁迫作用,使其生长量减少,叶绿素a、类胡萝卜素含量降低.  相似文献   
49.
Yin D  Hu S  Jin H  Yu L 《Chemosphere》2003,52(1):67-73
Freshwater quality criteria of 2,4,6-trichlorophenol (2,4,6-TCP) were developed with particular reference to the aquatic biota in China, and based on USEPA's guidelines. Acute toxicity tests were performed on nine different domestic species indigenous to China to determine 48 h LC(50) and 96 h LC(50) values for 2,4,6-TCP. In addition, 21 d survival-reproduction test with Daphnia magna, 30 d embryo-larval test with Carassius auratus, 60 d fry-juvenile test with Ctenopharyngodon idellus, 30 d early life stage test with Bufo bufo gargarizans and 96 h growth inhibition test with Scenedesmus obliqaus were also conducted to estimate lower chronic limit and upper chronic limit values. The final acute value (FAV) was 2.01 mg/l 2,4,6-TCP. Acute-to-chronic ratios ranged from 5.01 to 12.2. The final chronic value (FCV) and the final plant value (FPV) of 2,4,6-TCP were 0.226 and 2.24 mg/l respectively. Based on FAV, FCV and FPV for 2,4,6-TCP, a criteria maximum concentration of 1.01 mg/l and a criterion continuous concentration of 0.226 mg/l were derived. The results of this study provide useful data for deriving national or local water quality criteria for 2,4,6-TCP based on aquatic biota in China.  相似文献   
50.
To improve the efficiency of water use and reuse, a digitalized water network system was implemented in a steel industrial complex. The system consisted of four parts: online instrument and sensing devices, programmable logic controller, data communication network and control center based on expert knowledge. The system achieved real-time monitoring, diagnosis, and early warning of cooling water system using data collected inline, and enabled data connectivity and transmission of self-developed software applications on personal computer. This research used a steel enterprise as a case study. After the analysis of its cooling water system and water-saving potential using water balance test, a digitalized water network was evaluated and implemented, and we believe this network can be suitable for steel industry in general.  相似文献   
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