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Much of the methodology employed for characterizing wastewater and in modeling wastewater treatment processes employs off-line analysis. Off-line analysis is time consuming and not ideally suited to developing process control strategies. Clearly a rapid, inexpensive and reliable method suitable for following organic consumption and biomass production on-line would be very useful. In this study multiple excitation—multiple emission fluorometry was examined as a method for monitoring wastewater treatment processes. Results were first obtained for defined protein solutions and activated sludge to identify characteristic excitation and emission wavelength pairs. These results were then used to develop a rapid off-line assay for measurement of synthetic feeds consisting of protein substrates for batch aerobic and anoxic wastewater treatment processes and for on-line monitoring of cellular metabolic states in an anoxic process. Step-wise multiple regression and principal component analysis were employed for data analysis. The former was used to determine the most informative excitation and emission wavelength pairs while the latter was applied to reduce fluorescent spectra dimensions. Analysis of the batch kinetics suggests that this approach is valid and revealed some dynamic features of protein utilization and biomass accumulation under aerobic and anoxic conditions. A correlation was developed between COD-removal rates and the fluorescence signals in the two processes using fluorescent emission spectra rather than single signals. The data suggests that this multiple excitation—multiple emission fluorometry may be a suitable method for following wastewater and activated sludge dynamics and could be used as the basis for the development of expert system based biosensors. 相似文献
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偏最小二乘回归法利用了成分提取的工作思路,在变量系统中选取若干对系统具有最佳解释能力的新综合变量,而非直接考虑因变量与自变量进行回归建模,因而能有效地解决自变量之间具有多重相关性的问题。应用该法针对边坡工程安全监测变量及其影响因子间的复杂相关性进行研究。通过对锦屏一级水电站左岸边坡深部变形的实测资料的建模分析表明,偏最小二乘回归法适用于对复杂相关的因子进行建模,通过交叉有效性检验确保模型的精度,同时对引起边坡变形的影响因子的重要程度进行排序,因而在边坡工程安全监测资料的统计分析方向具有广阔的应用前景。 相似文献
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Evaluating sludge minimization caused by predation and viral infection based on the extended activated sludge model No. 2d 总被引:1,自引:0,他引:1
The Activated Sludge Model No. 2d (ASM2d) was extended to incorporate the processes of both predation and viral infection. The extended model was used to evaluate the contributions of predation and viral infection to sludge minimization in a sequencing batch reactor (SBR) system enriching polyphosphate-accumulating organisms (PAOs). Three individual decay processes formulated according to the general model rules were used in the extended model. The model was firstly calibrated and validated by different experimental results. It was used to evaluate the potential extent of predation and viral infection on sludge minimization. Simulations indicate that predation contributes roughly two times more to sludge minimization than viral infection in the SBR system enriching PAOs. The sensitivity analyses of the selected key parameters reveal that there are thresholds on both predation and viral infection rates, if they are too large a minimal sludge retention time is obtained and the effluent quality is deteriorating. Due to the thresholds, the contributions of predation and viral infection to sludge minimization are limited to a maximal extent of about 21% and 9%, respectively. However, it should be noted that the parameters concerning predation and viral infection were not calibrated separately by independent experiment in our study due to the lack of an effective method, especially for the parameters regarding viral infection. Therefore, it is essential to better evaluate these parameters in the future. 相似文献
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Groundwater quality monitoring is considered to be an essential component of any sanitation programme where simultaneous groundwater abstraction and on-site waste disposal are proposed. The low priority currently accorded to monitoring programmes reflects inexperience of monitoring in general and consequent misconceptions about the content and benefits of groundwater quality monitoring.
The purpose of this paper is two-fold. Firstly to explain why groundwater quality monitoring is a requisite component of all pilot sanitation projects which involve on-site disposal of human excreta. Secondly, to demonstrate that it is not unrealistic to expect groundwater quality monitoring to be carried out in relation to all such pilot projects.
The resource constraints inherent in developing countries need not prohibit routine monitoring. However, it is important to define clearly the specific objectives of any monitoring programme and to design a sampling network appropriate to both these objectives and the site conditions. Monitoring must not be confused with initial assessment of prevailing conditions, nor with research studies, for which the aims, duration, technical complexity, and hence investment, are quite different.
Monitoring is a process which can evolve with increased investment to address various questions regarding the causes, nature and processes of groundwater contamination. 相似文献
The purpose of this paper is two-fold. Firstly to explain why groundwater quality monitoring is a requisite component of all pilot sanitation projects which involve on-site disposal of human excreta. Secondly, to demonstrate that it is not unrealistic to expect groundwater quality monitoring to be carried out in relation to all such pilot projects.
The resource constraints inherent in developing countries need not prohibit routine monitoring. However, it is important to define clearly the specific objectives of any monitoring programme and to design a sampling network appropriate to both these objectives and the site conditions. Monitoring must not be confused with initial assessment of prevailing conditions, nor with research studies, for which the aims, duration, technical complexity, and hence investment, are quite different.
Monitoring is a process which can evolve with increased investment to address various questions regarding the causes, nature and processes of groundwater contamination. 相似文献
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边坡工程分布式光纤监测技术研究 总被引:10,自引:2,他引:8
通过对边坡及其加固工程进行实时、在线监测,可掌握边坡的变形动态,对滑坡进行预警。分布式光纤传感技术与常规监测方法相比具有很大的优越性,如分布式、长距离、实时性和长期稳定性等,可满足加固工程安全监测和滑坡早期预警的要求。对布里渊光时域反射技术(BOTDR)的测量原理和优点进行介绍,设计一套基于BOTDR的新型分布式边坡监测系统,详细阐述工程应用中传感光纤的布设方法、光纤保护和温度补偿技术等。通过将传感光纤按一定的方式布设在加固工程及坡体内,并相互连接构成基于BOTDR的边坡分布式光纤监测系统,进而实现对整个边坡的远程分布式监测。以实际工程为例,对边坡分布式变形监测结果进行分析。结果表明,基于BOTDR技术的边坡分布式光纤监测系统能够准确地反映边坡及加固工程的变形情况,具有显著的优越性,可用于边坡稳定性的监测和预报。 相似文献
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An expanded unified model for the biomass fractions, soluble-organic fractions, and oxygen-uptake rates considering extracellular polymeric substances (EPS), intracellular storage products (XSTO), and predators for activated sludge is used to study the impacts of predators on biomass components and oxygen uptake. The new model is applied to evaluate how predation affects the oxygen-uptake rate (OUR) and the different forms of biomass: active bacteria (XH), XEPS, and XSTO, under dynamic feast-and-famine and continuous conditions. For the dynamic conditions of a sequencing batch reactor (SBR), eliminating predators from the model increases XH and XEPS fractions significantly, and this causes the substantial increases in OUR and MLVSS once the famine period begins. An analysis of how the OUR is distributed among the several respiration processes shows that the predation of XH is the most significant oxygen utilization rate process in the system under famine conditions of an SBR. Application of the model to simulate the long-term operation of an SBR indicates that predators reach their maximum fraction in the MLVSS (∼4% of MLVSS) at a solids retention time of about 13 days, but they are washed out at a solids retention time less than ∼3 days. Simulation for a continuous system indicates that predators take more time (about 800 h) to reach steady state and reach their maximum fraction (∼5.5%) at an SRT of ∼14 days. Comparison of SBR and continuous systems reveals that the predators have greater impact in the continuous system because the permanent near-famine condition accentuates predation processes. 相似文献
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小波变换应用于金属氧化物避雷器在线监测信号处理的研究 总被引:2,自引:0,他引:2
利用小波分析可以同时在时域和频域进行局部分析的特点,将其应用于具有较大现场干扰背景的金属氧化物避雷器(以下简称MOA)泄漏电流在线监测的信号处理,对混合了噪音的原始信号进行小波分解,实现真实信号和噪音的分离,并进行了计算机仿真,证明这个方法是有效的。 相似文献
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Biological nitrogen removal with enhanced phosphate uptake in a sequencing batch reactor using single sludge system 总被引:61,自引:0,他引:61
Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR). Significant amounts of phosphorus-accumulation organisms (PAOs) capable of denitrification could be accumulated in a single sludge system coexisting with nitrifiers. The ratio of the anoxic phosphate uptake to the aerobic phosphate uptake capacity was increased from 11% to 64% by introducing an anoxic phase in an anaerobic aerobic SBR. The (AO)2 SBR system showed stable phosphorus and nitrogen removal performance. Average removal efficiencies of TOC, total nitrogen, and phosphorus were 92%, 88%, and 100%, respectively. It was found that nitrite (up to 10 mg NO2(-)-N/l) was not detrimental to the anoxic phosphate uptake and could serve as an electron acceptor like nitrate. In fact, the phosphate uptake rate was even faster in the presence of nitrite as an electron acceptor compared to the presence of nitrate. It was found that on-line sensor values of pH, ORP, and DO were somehow related with the dynamic behaviours of nutrient concentrations (NH4+, NO3-, and PO4(3-)) in the SBR. These on-line sensor values were used as real-time control parameters to adjust the duration of each operational phase in the (AO)2 SBR. The real-time controlled SBR exhibited better performance in the removal of phosphorus and nitrogen than the SBR with fixed-time operation. 相似文献
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两种序批式生物系统处理屠宰废水的对比试验 总被引:4,自引:0,他引:4
在相同的运行条件下,考察了序批式活性污泥系统和生物膜系统对屠宰废水的处理效果.试验结果表明,两种方法都是可行的,但生物膜系统的处理效果优于括性污泥系统,达到相同污染物去除率时,生物膜系统的运行管理更方便,且克服了活性污泥系统存在的一些问题. 相似文献
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基于布里渊光时域反射计(BOTDR)的工作原理,介绍了光纤测试技术是近年来国际上研发成功的一项新型的分布式光电传感技术。实践证明通过该技术,将传感光纤按照一定的工艺粘贴在埋置于土体中的测斜管上,由传感光纤实测的应变分布,可以实现深部土体水平位移的在线监测。 相似文献
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处理屠宰废水的一种新方法──序批式生物膜法 总被引:4,自引:0,他引:4
方茜 《华南建设学院西院学报》2000,(3)
采取对比研究的方法,在相同条件下考察序批式生物膜法和序批式活性污泥法对屠宰废水的处理效果。通过对试验结果的分析表明,与序批式活性污泥法相比,序批式生物膜法不仅可以克服序批式活性污泥法的弊端,而且其处理效果更好、运行管理更为方便,是一种优化处理屠宰废水的新方法,具有广阔的应用前景。 相似文献
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盘形悬式瓷绝缘子的在线检测 总被引:1,自引:1,他引:0
讨论了检测盘形悬式瓷绝缘子的火花间隙法、电压分布法、测量绝缘电阻法、航测法和地面初判法。认为采用火花间隙法和电压分布法检测绝缘子,有漏检、误判等现象;采用在线绝缘电阻法进行测试,可靠性较高。同时指出,航测法和地面初判法是今后在线检测的发展方向。 相似文献
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The efficiency of enhanced biological phosphorus removal from real wastewater affected by different ratios of acetic to propionic acid 总被引:28,自引:0,他引:28
The effect of different ratios of propionic to acetic acid on the efficiency of enhanced biological phosphorus removal (EBPR) from real wastewater supplemented with volatile fatty acids (VFAs) was investigated. Two sequencing batch reactors (SBRs) were used to acclimate two types (SBR1 and SBR2) of biomass. They were cultured and studied using real wastewater with an average propionic to acetic acid carbon molar ratio of 0.16 and 2.06, respectively. The laboratory results showed that for a given long-term cultured biomass the more the soluble ortho-phosphate (SOP) was released in the anaerobic stage, the higher the SOP was taken up in the aerobic phase. However, the SBR2 biomass had a much greater SOP uptake to release ratio than SBR1, which resulted in a higher SOP removal efficiency than SBR1 (average 87.3% versus 76.9% in SBRs experiments, and 93.5% against 68.1% in batch tests). The SBR2 biomass therefore had a higher SOP uptake ability than the SBR1 for a given amount of SOP release. In addition, the SBR1 had a higher secondary SOP release following VFAs uptake. It was found that the SBR2 biomass synthesized and utilized less observable polyhydroxyalkanoates (PHAs) during the anaerobic and aerobic stage respectively than SBR1. The apparent PHAs utilization efficiency for SOP uptake with the SBR2 biomass was much greater than with the SBR1, and the SBR2 biomass synthesized less glycogen during aerobiosis than SBR1, which might mean a higher PHAs fraction was used for SOP removal, resulting in the increased efficiency with the long-term cultured SBR2 biomass. Higher propionic acid content led to superior EBPR in long-term cultivation, but was transiently detrimental in the short term. 相似文献
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对影响因素未知且没有先验信息的污染图像进行恢复和重构是图像处理的一项主要任务。ICA(Independent Component Analysis,独立分量分析)是20世纪90年代后期发展起来的一种盲信号处理方法,并成功应用于图像盲分离。近年来ICA技术得到了进一步发展,出现了多种算法。为了分析各种算法在图像盲分离中的优劣,对SOBI(二阶盲辨识)、JADE(联合近似特征矩阵对角化)、FastICA(快速独立分量分析)和KICA(基于非线性子空间的核独立分量分析)算法进行了比较实验。结果表明,KICA算法分离效果最好,FastICA算法次之;但是如果源图像或者混合图像中含有噪声,则以上四种方法分离效果都不佳。 相似文献