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371.
针对现有活性污泥检测方法过程繁琐、耗时长、检测结果滞后的局限,提出了光偏转快速检测法.在污泥负荷为0.33KgCOD/(kg MLSS·d)、水力停留时间为15h的印染废水完全混合式活性污泥系统中,投放粒径4mm、具有20μm微孔结构的聚乙烯醇(PVA)凝胶小球以负载微生物,并在小球达到稳定状态后,对其表面处因外界溶液与微生物代谢产物交换产生的浓度梯度变化,借助光斑分析仪进行光偏转检测,同时测定与光偏转检测结果相对应的15h后的出水COD及COD去除率.连续10个月的检测发现,小球中富集的主要为细菌,当进水COD由91.95mg/L增至519.4mg/L时,小球的光偏转值从229.51μm增加至299.97μm,COD去除率从16.03%提高至66.99%;当DO浓度为1.5mg/L~5mg/L时,小球光偏转值在DO=4mg/L时增至最大为309.3mg/L,对应状态下COD去除率增至最大为61.18%;在pH值为6~9时,小球光偏转值在pH=7时增至最大为293.96μm,对应状态下COD去除率也达到最大值为64.83%;当重金属Cr3+浓度增至50mg/L时,微生物活性逐渐受到抑制,小球光偏转值在Cr3+浓度为20mg/L时降至269.7μm,随后随着Cr3+浓度的增加,微生物细胞受损,胞内物质溶出,小球光偏转值有所增大,对应状态下COD去除率从52.5%持续降低至25.73%.结果表明:该方法可快速获得活性污泥代谢状态变化信息,且依据特定条件下小球光偏转值变化能够预测随后印染废水COD的去除效果.利用三维荧光光谱初步探究了微生物代谢引发光偏转的机理,发现参与微生物代谢的主要有机物为酪氨酸、芳香类蛋白及色氨酸.  相似文献   
372.
为了解UV-B增强条件下农田N2O响应规律,采用室外盆栽实验,研究了地表UV-B辐射增强20%对土壤-冬小麦系统N2O排放的影响及其影响机理.结果表明,在小麦返青期,UV-B辐射增强处理对该系统N2O的排放影响不显著;在小麦的拔节期,UV-B辐射增强处理显著降低了土壤-小麦系统N2O的排放,并减少了该系统的呼吸速率.UV-B辐射增强对N2O的影响机理主要表现在对小麦植株N代谢过程的影响,如显著增加  相似文献   
373.
对生物活性炭滤池启动运行中微生物生物量、生物活性、代谢功能及水质指标的变化情况进行连续分析.结果表明,生物活性炭滤池中异养微生物的平板计数生物量变化呈"S"形曲线,与微生物生长规律相符合,这反映滤池中微生物群落有明显的适应期、对数期和稳定期等生长阶段.脱氢酶活性随挂膜时间延长不断增加,第30天后达到稳定水平.滤池中微生物群落碳源代谢能力随挂膜时间的推进而增强,第40天时微生物群落的丰富度指数和Shannon多样性指数达到相对稳定值.氨氮(NH4+-N)与高锰酸盐指数(CODMn)去除率经过降低—缓慢上升—稳定的变化过程后,在第40天时去除率分别达到80%和28%左右.滤池启动运行29 d后溶解氧(DO)消耗率基本稳定,其值为18%.因此,在生物活性炭滤池挂膜过程中,分析微生物生长代谢与水质的变化特征可判断挂膜启动过程是否完成.图6表1参22  相似文献   
374.
Excessive input of phosphorus into natural water bodies as a result of anthropogenic processes is an escalating factor that leads to eutrophication. Hence, quantifying the pathway of phosphorus throughout the socioeconomic system is essential for the selection of appropriate measures to mitigate phosphorus discharge. The study develops an analytical model of anthropogenic phosphorus flows within a socioeconomic system based on substance flow analysis. The model consists of five major subsystems: the phosphorous chemical industry, agriculture, animal feeding, human consumption, and waste management. The results show that the total input and output of phosphorus in Chaohu City over 2008 are 8517.70 ton (t) and 4682.76 t, respectively. The estimation of phosphorus discharged into local surface water is 544.22 t, which primarily comes from agriculture (391.99 t, 72.03%), followed by large-scale farming (55.70 t, 10.23%), rural consumption (56.81 t, 10.44%), urban consumption (30.42 t, 5.59%), and waste management (9.30 t, 1.71%). Intensive input of fertilizers in agricultural practices was identified as the most important source of phosphorus load on local surface water. Hence, we propose that the eutrophication of local water bodies could be addressed by optimizing local industrial structure, developing ecological and organic-based agriculture, and improving waste collection and disposal practices.  相似文献   
375.
土壤含水层处理去除可吸附有机卤化物的试验研究   总被引:14,自引:0,他引:14  
研究了土壤含水层处理工艺对典型城市二级出水以可吸附有机卤化物表征的有机物的去除效果。投加24mg/l臭氧预处理后,再经好氧含水层处理可去除约32%的AOX,厌氧柱进水中投加各80mg/l葡萄糖和谷氨酸,运行稳定性,通过共谢作用,可去除约55%的AOX。  相似文献   
376.
The metabolism of 14C-clodinafop-propargyl (CfP) was examined in cell cultures of wheat (Triticum aestivum L. cv. ‘Heines Koga II’) and tobacco (Nicotiana tabacum L.). Besides the non-transgenic tobacco culture, cultures transformed separately with cDNA of human cytochrome P450-monooxygenases (P450s) CYP1A1, CYP1A2, CYP3A4, CYP2B6 and CYP2C19 were examined. Experiments with wheat were executed in the presence and absence of safener cloquintocet-mexyl (CqM). After 48 h of incubation, only about 10% of applied 14C was found in media (both tobacco and wheat). Non-extractable residues of 14C-CfP in wheat cells were 16.54% (without CqM) and 30.87% (with CqM). In all tobacco cultures, 82.41–92.46% of applied radioactivity was recovered in cell extracts. In contrast to wheat, non-extractable residues amounted only to 1.50–2.82%. As determined by radio-thin layer chromatography (TLC) and -high-performance liquid chromatography (HPLC), the parent CfP was not found in the cell extracts of wheat; in tobacco cell extracts, only traces of CfP were detected. After a hydrolysis of assumed carbohydrate conjugates of CfP derived polar 14C-labeled compounds, TLC and HPLC analysis showed that in wheat, a more complex pattern of metabolites of CfP were observed as compared to all tobacco cultures. In hydrolysates resulting from wheat, the identity of three primary products was confirmed by means of GC-EI-MS: free acid clodinafop (Cf), hydroxy-Cf hydroxylated at the pyridinyl moiety, and 4-(5-chloro-3-fluoropyridin-2-yloxy)phenol. In hydrolysates derived from all tobacco cultures, main metabolite was Cf besides only traces of further unidentified products. Differences among the different tobacco cultures (non-transgenic, transgenic) did not emerge. According to kinetics of disappearance of primary metabolite Cf as well as formation of polar soluble products and non-extractable residues, metabolization of CfP proceeded at a noticeably higher rate in wheat cells treated with safener CqM than in cells without CqM treatment. Thus, these results indicated a stimulation of CfP's metabolism by CqM, although metabolic profiles observed in CqM treated and non-treated cells (after hydrolysis) were qualitatively similar. The findings obtained from all tobacco cultures suggested that with the exception of ester cleavage to Cf, CfP cannot be metabolized by tobacco itself or by the human P450s examined.  相似文献   
377.
Different biotic and abiotic factors were found to play a vital role in attenuating metalaxyl residues in soil. In addition to metalaxyl many other products were found by HPLC and GC‐MS analysis while studying its soil metabolism in presence of natural sunlight. Three compounds were identified and characterized: 2,6‐dimethylaniline, 2,6‐dimethyl‐N‐ethylacetanilide and N‐(2,6‐dimethyl phenyl) alanine methyl ester.  相似文献   
378.
中华绒螯蟹幼蟹饥饿代谢研究   总被引:21,自引:0,他引:21  
于1998年10~12月在华东师范大学生物学系动物学实验室,对体重为(1.42±0.69)g的幼蟹在(20±0.5)℃温度条件下进行饥饿实验,研究了饥饿对中华绒螯蟹幼蟹代谢的影响.结果表明,经过30d的饥饿处理,幼蟹的耗氧率降低为摄食状态的45.8%;CO2排出率减小为摄食状态的54.1%;NH3-N排泄率减小为62.3%.耗氧率和CO2排出率、NH3-N排泄率的变化差别较大,耗氧率和CO2排出率的减小可分为4个阶段,而NH3-N排泄率的减小仅可分3个阶段.与此同时,幼蟹的标准代谢水平同样受到饥饿的影响,饥饿30d后,由8.15Jg-1h-1减小为3.97Jg-1h-1;在饥饿幼蟹的代谢中,脂肪消耗最多,其次是碳水化合物.图2表2参18  相似文献   
379.
铜污染草地对放牧乌蒙半细毛羊矿物质元素代谢的影响   总被引:1,自引:0,他引:1  
为了评价草地铜污染对放牧乌蒙半细毛羊的影响,探讨铜污染的治理方法,在乌蒙山区的妈姑镇和凉水沟开展草地放牧试验和矿物质元素补充研究。应用原子发射光谱分析土壤、牧草和动物组织的重金属含量,应用全自动血液分析仪分析血液指标。放牧试验的结果显示:铜污染草地放牧明显增加了动物组织铜和锌的含量(P 0.01),降低了动物组织钼和铁的含量(P 0.01),试验结束时,试验组动物的血红蛋白(Hb)、红细胞压积(PCV)、红细胞数(RBC)和平均红细胞体积(MCV)显著低于对照组(P 0.01),羊毛产量和长度显著低于对照组(P 0.01)。矿物质元素补充试验的结果显示:补充硫酸钠明显降低了铜污染草地放牧动物血液和肝脏铜元素含量,补充试验结束时,处理Ⅰ组动物血液的Hb、PCV、RBC和MCV显著高于处理Ⅱ组(P 0.01),血液指标达到正常范围。处理Ⅱ组动物血液和肝脏铜元素的含量继续升高,动物组织钼的含量继续降低(P 0.01),Hb、PCV和RBC继续下降,试验结束时出现溶血性贫血,但补充硫对羊毛品质的相关指标没有显著的影响。研究表明,铜污染草地严重影响了乌蒙半细毛羊的矿物质代谢,补充硫酸钠可以部分拮抗铜的毒性。  相似文献   
380.
Urban Metal Management The Example of Lead   总被引:1,自引:0,他引:1  
The metal metabolism of an urban region, the City ofVienna, was investigated to discuss urban metal management strategies in view of environmental protection and resource conservation. About 90% of the metal stock is located in Vienna's buildings and infrastructure, whilst only 10% is in the landfills. The city stock represents a potential source for diffusive emissions. However, the control of the current environmental policy concentrates mainly on landfill emissions. Diffusive emissions resulting from the losses over the use of metal containing goods in the city are widely dispersed and cannot be easily controlled due to numerous non-point sources. First investigations indicate that for certain applications, the diffusive stock emissions are as significant as other sources. At present, Vienna's known diffusive and point source lead emissions into air and water are about 40 to 50 times higher than comparable past loadings from geogenic Vienna. Furthermore, a life cycle approach from acid car batteries indicates that sustainable lead management should consider flows and stocks in the hinterland of the city too. The city metal stock also represents a potential resource. Leaded water pipes built-in in Vienna's city stock have the potential to produce 1.6 million traditional car batteries. In future such city mining strategies can partly replace ore mining.  相似文献   
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