阳离子染料废水治理技术

介绍了阳离子染料废水的特点,以及近年来阳离子染料废水的各种处理技术,并对阳离子染料废水处理技术的发展进行了展望,指出阳离子废水处理技术正朝着各种工艺优化组合的方向发展。     

白腐真菌处理染料废水研究进展

本文针对染料废水处理中存在的问题，介绍了利用白腐真菌处理废水的一般机理及其优势。在此基础上。对该菌种在处理染料废水研究应用中的筛选与降解机理、主要工艺条件对处理效果的影响和反应器类型等方面的研究成果给予了分析与评述。     

染料废水脱色的物理化学处理技术

染料废水目前主要的脱色方法有吸附、混凝、氧化还原和生化法.活性炭吸附适用于低浓度的染料废水处理.聚硅硫酸铁混凝效果与Fe/SiO4摩尔比和pH值相关.氢氧化镁可有效去除印染废水中的直接红染料.有机絮凝剂往往需要和其它药剂复配.氧化法脱色率大,但成本高昂,且受染料废水的组成、氧化性及pH值影响.还原法药剂价格低廉,但还原降解产物具有毒性,必须经过二次处理.生物法成本较低,又受制于染料的生物降解性.因此发展多种手段联合应用已是当前染料废水处理的研究方向.     

重金属废水生化处理技术的研究进展

处理重金属废水的传统方法在投资和运行费用上都较高，加之沉淀去除效果不太理想，近年来国内外进行了大量的生化法去除重金属的研究。本文介绍了生物吸附法、生物絮凝法、微生物代谢法和植物吸收法。生化法处理重金属废水，成本低，效益高，易管理，可回收重金属，有利于生态环境的改善，具有十分广阔的应用前号。     

壳聚糖吸附处理废水的研究进展

壳聚糖吸附处理废水的研究包括其对废水吸附性能和吸附机理的研究两个方面。壳聚糖表现出了良好的吸附废水中重金属离子、染料分子和其它易引起变异物质的能力;壳聚糖对金属离子和染料的吸附机理模型研究理论意义重大,它将进一步推动壳聚糖的实际工程应用。     

微生物法处理电镀废水技术概况与展望

微生物法处理电镀废水技术倍受关注，文章在介绍国内外微生物法处理电镀废水的试验研究和大规模工业生产的基础上，总结了微生物法处理电镀废水的机理、工艺流程，优点及存在问题，并指出了这一技术的研究热点和发展前景。     

高浓度难降解有机废水处理技术综述

高浓度难降解有机废水的处理，是国内外污水处理界公认的难题。本文分析了这一类废水难于生物处理的主要原因，并在此基础上对近年来国内外处理焦化废水、制药废水等高浓度难降解废水的技术和研究作了介绍与评价。     

电化学技术及其在印染废水处理中的应用

电化学技术因其具有高度灵活性、易于控制、污染少等特点倍受研究者的重视。本文主要介绍了电化学技术的各种方法，包括电沉积法、电化学氧化还原法、电吸附法和电渗析法等基本原理。采用上述方法处理染料废水均得到良好效果。同时指出了电化学技术存在电极消耗多、电流效率低等问题；在开发新型电极材料和电化学反应器等方面有待研究。     

焦化废水处理技术研究进展

焦化废水主要来自炼焦和煤气净化过程产生的废水,含有难降解的有机化合物。目前,焦化废水一般按常规方法先进行预处理,然后进行生物脱酚二次处理。近年来,国内外学者开展了大量的研究工作,找到了许多比较有效的焦化废水治理技术,主要有生物处理法、化学处理法、物理化学处理法和废水循环利用。     

膜法染料废水处理及膜污染的防治

介绍了近年来膜分离技术在染料行业中的应用现状。膜技术的应用包括印染废水的处理、回用等方面。文章同时介绍了膜的污染及其防治等相关方面的内容。     

Cost-effectiveness of tillage methods to reduce phosphorus loss from agricultural land

In this paper, we estimate the cost-effectiveness of tillage methods as a measure to reduce phosphorus loss. The study was based on real-world information on costs. Data on phosphorus loss for different soil tillage methods were modelled. The cost-effectiveness of various soil tillage methods were related to autumn ploughing. The results showed large variation in cost-effectiveness related to erosion risk. Furthermore, spring harrowing was the most cost-effective method to reduce phosphorus loss, followed by autumn harrowing and spring ploughing in spring cereals. Implementation of changed tillage methods showed lower costs for spring cereals compared to winter wheat. The differences in costs between areas were most evident for spring tillage due to differences in yields and agronomic management. Cost-effectiveness is an important criterion in selecting mitigation methods, but due to large variations in the effect of changed tillage, these should be locally adapted to the high risk areas of erosion.     

MULTIVARIATE TREND TESTING OF LAKE WATER QUALITY1

ABSTRACT: Multivariate methods of trend analysis offer the potential for higher power in detecting gradual water quality changes as compared to multiple applications of univariate tests. Simulation experiments were used to investigate the power advantages of multivariate methods for both linear model and Mann-Kendall based approaches. The experiments focused on quarterly observations of three water quality variables with no serial correlation and with several different intervariable correlation structures. The multivariate methods were generally more powerful than the univariate methods, offering the greatest advantage in situations where water quality variables were positively correlated with trends in opposing directions. For illustration, both the univariate and multivariate versions of the Mann-Kendall based tests were applied to case study data from several lakes in Maine and New York which have been sampled as part of EPA's long term monitoring study of acid precipitation effects.     

前馈神经网络在环境评价和预测中的应用进展

本文针对水环境中复杂的不确定性及非线性关系,在水环境不确定性分析的基础上,详细阐述了以BP网络和RBF网络为代表的前馈神经网络法的基本原理,分析了两种方法的优点。同时,本文对两种方法在水环境影响评价工作中的应用现状进行总结,分析了两种方法的研究发展趋势。     

A COMPARISON OF SIX POTENTIAL EVAPOTRANSPIRATION METHODS FOR REGIONAL USE IN THE SOUTHEASTERN UNITED STATES1

ABSTRACT: Potential evapotranspiration (PET) is an important index of hydrologic budgets at different spatial scales and is a critical variable for understanding regional biological processes. It is often an important variable in estimating actual evapotranspiration (AET) in rainfall‐runoff and ecosystem modeling. However, PET is defined in different ways in the literature and quantitative estimation of PET with existing mathematical formulas produces inconsistent results. The objectives of this study are to contrast six commonly used PET methods and quantify the long term annual PET across a physiographic gradient of 36 forested watersheds in the southeastern United States. Three temperature based (Thornthwaite, Hamon, and Hargreaves‐Samani) and three radiation based (Turc, Makkink, and Priestley‐Taylor) PET methods are compared. Long term water balances (precipitation, streamflow, and AET) for 36 forest dominated watersheds from 0.25 to 8213 km² in size were estimated using associated hydrometeorological and land use databases. The study found that PET values calculated from the six methods were highly correlated (Pearson Correlation Coefficient 0.85 to 1.00). Multivariate statistical tests, however, showed that PET values from different methods were significantly different from each other. Greater differences were found among the temperature based PET methods than radiation based PET methods. In general, the Priestley‐Taylor, Turc, and Hamon methods performed better than the other PET methods. Based on the criteria of availability of input data and correlations with AET values, the Priestley‐Taylor, Turc, and Hamon methods are recommended for regional applications in the southeastern United States.     

Filyos River Streamflow Reconstruction from Tree‐Ring Chronologies with Nonparametric Approaches

The article presents nonparametric methods based on K nearest neighbors (KNNs), modified KNNs, and local polynomial techniques to reconstruct streamflow ensembles from tree‐ring data in Filyos River region (Turkey). Three methods were tested using cross‐validation for the overlap period, 1963‐1997 for which the tree‐ring and streamflow data are available. It was found that for the study where the length of the overlap period was limited, a nonparametric method based on a local polynomial technique provides simulations that have a slightly better solution than the other methods. After verification using standard statistical techniques, these methods were utilized to develop streamflow reconstructions from tree‐ring data for the paleo‐hydrologic period (1657‐1963). These reconstructions of seasonal low and high flows were discussed with the obtained flood duration curve. They were also compared with the historical archives and other tree‐ring reconstructions data available in the same river. Overall, the utility and limitations of these methods and the resulting streamflow simulations were discussed to assess the long‐term discharge behavior of Filyos River and to evaluate water supply reliability.     

ESTIMATING PARAMETERS OF EV1 DISTRIBUTION FOR FLOOD FREQUENCY ANALYSIS1

ABSTRACT: The parameters of the extreme value type 1 distribution were estimated for 55 annual flood data sets by seven methods. These are the methods of (1) moments, (2) probability weighted moments, (3) mixed moments, (4) maximum likelihood estimation, (5) incomplete means, (6) principle of maximum entropy, and (7) least squares. The method of maximum likelihood estimation was found to be the best and the method of incomplete means the worst. The differences between the methods of principle of maximum entropy, probability weighted moments, moments, and least squares were only minor. The difference between these methods and the method of maximum likelihood was not pronounced.     

SPATIAL ANALYSIS FOR MONTHLY RAINFALL IN SOUTH FLORIDA1

ABSTRACT: Several methods have been developed to interpolate point rainfall data and integrate areal rainfall data from any network of stations. From previous studies, it can be concluded that models for spatial analysis of rainfall are dependent on topography, area of analysis, type of rainfall, and density of gauging network. The purpose of this study is to evaluate a set of six appropriate models for point and areal rainfall estimations over a 4000 square mile area in South Florida. In this study, a case of developing spatial continuity model for monthly rainfall from a database that had various lengths of records and missing data is documented. The spatial correlation and variogram models for monthly rainfall were developed. Six methods of spatial interpolation were applied and the results validated with historical observations. The results of the study indicate that the multiquadric, kriging, and optimal interpolation schemes are the best three methods for interpolation of monthly rainfall within the study area. The optimal and kriging methods have the advantage of providing estimates of the error of interpolation. The optimal interpolation method uses the spatial correlation function and the kriging method uses the variogram function. The two spatial functions are related. Either of the two methods provide good estimates of monthly point and areal rainfall in the study area.     

Influence of data preprocessing on the quantitative determination of nutrient content in poultry manure by near infrared spectroscopy

With increasing concern over potential polltion from farm wastes, there is a need for rapid and robust methods that can analyze livestock manure nutrient content. The near infrared spectroscopy (NIRS) method was used to determine nutrient content in diverse poultry manure samples (n=91). Various standard preprocessing methods (derivatives, multiplicative scatter correction, Savitsky-Golay smoothing, and standard normal variate) were applied to reduce data systemic noise. In addition, a new preprocessing method known as direct orthogonal signal correction (DOSC) was tested. Calibration models for ammonium nitrogen, total potassium, total nitrogen, and total phosphorus were developed with the partial least squares (PLS) method. The results showed that all the preprocessed data improved prediction results compared with the non-preprocessing method. Compared with the other preprocessing methods, the DOSC method gave the best results. The DOSC method achieved moderately successful prediction for ammonium nitrogen, total nitrogen, and total phosphorus. However, all preprocessing methods did not provide reliable prediction for total potassium. This indicates the DOSC method, especially combined with other preprocessing methods, needs further study to allow a more complete predictive analysis of manure nutrient content.     

Differential Assessment of Designations of Wetland Status Using Two Delineation Methods

Two different methods are commonly used to delineate and characterize wetlands. The U.S. Army Corps of Engineers (ACOE) delineation method uses field observation of hydrology, soils, and vegetation. The U.S. Fish and Wildlife Service’s National Wetland Inventory Program (NWI) relies on remote sensing and photointerpretation. This study compared designations of wetland status at selected study sites using both methods. Twenty wetlands from the Wetland Boundaries Map of the Ausable–Boquet River Basin (created using the revised NWI method) in the Ausable River watershed in Essex and Clinton Counties, NY, were selected for this study. Sampling sites within and beyond the NWI wetland boundaries were selected. During the summers of 2008 and 2009, wetland hydrology, soils, and vegetation were examined for wetland indicators following the methods described in the ACOE delineation manual. The study shows that the two methods agree at 78 % of the sampling sites and disagree at 22 % of the sites. Ninety percent of the sampling locations within the wetland boundaries on the NWI maps were categorized as ACOE wetlands with all three ACOE wetland indicators present. A binary linear logistic regression model analyzed the relationship between the designations of the two methods. The outcome of the model indicates that 83 % of the time, the two wetland designation methods agree. When discrepancies are found, it is the presence or absence of wetland hydrology and vegetation that causes the differences in delineation.     

纳米二氧化钛粉体的制备及对染料脱色的研究

以钛酸四丁酯为原料,采用溶胶-凝胶法、水热沉淀法、水解法制备了纳米二氧化钛粉体。经XRD对三种方法制得粉体进行了表征,讨论了三种方法的优缺点。以水解法制得二氧化钛粉对六种染料进行了脱色研究,结果表明其有良好的光催化脱色性能。