沈阳市冬季环境空气质量统计预报模型建立及应用

利用沈阳市2013年1—2月大气自动监测数据和同期气象资料,选取19项预报因子,采用逐步回归方法建立了沈阳市冬季环境空气质量统计预报模型,预报项目包括细颗粒物(PM2.5)、可吸入颗粒物(PM10)、二氧化硫(SO2)、二氧化氮(NO2)、一氧化碳(CO)日均浓度及臭氧(O3)日最大8 h平均浓度。2013年11月至2014年1月,应用该模型并结合人为经验修订,开展了沈阳市环境空气质量预报工作,预报结果与实测结果的对比验证结果表明,环境空气预测结果级别准确率达到79.1%,首要污染物准确率为73.6%。     

Receptor modeling for source apportionment of polycyclic aromatic hydrocarbons in urban atmosphere

This study reports source apportionment of polycyclic aromatic hydrocarbons (PAHs) in particulate depositions on vegetation foliages near highway in the urban environment of Lucknow city (India) using the principal components analysis/absolute principal components scores (PCA/APCS) receptor modeling approach. The multivariate method enables identification of major PAHs sources along with their quantitative contributions with respect to individual PAH. The PCA identified three major sources of PAHs viz. combustion, vehicular emissions, and diesel based activities. The PCA/APCS receptor modeling approach revealed that the combustion sources (natural gas, wood, coal/coke, biomass) contributed 19–97% of various PAHs, vehicular emissions 0–70%, diesel based sources 0–81% and other miscellaneous sources 0–20% of different PAHs. The contributions of major pyrolytic and petrogenic sources to the total PAHs were 56 and 42%, respectively. Further, the combustion related sources contribute major fraction of the carcinogenic PAHs in the study area. High correlation coefficient (R ² > 0.75 for most PAHs) between the measured and predicted concentrations of PAHs suggests for the applicability of the PCA/APCS receptor modeling approach for estimation of source contribution to the PAHs in particulates.     

多元回归和BP人工神经网络模型对混合厌氧消化产气量的预测研究

在中温且控制pH值条件下,对脂肪类单基质和城市污水厂剩余污泥进行混合厌氧消化试验。基于多元回归原理和BP人工神经网络原理,对其建立产气量预测模型。由实验数据计算得出:两个阶段多元回归模型的预测平均准确率分别为75.69%和79.29%;BP神经网络模型的预测平均准确率为79.05%。通过对比两种模型的预测结果可知,两种模型都有较高的预测准确率,但BP模型的预测准确率更高,更适用于混合厌氧消化产气量预测。     

Characterization of dissolved organic matter using high-performance liquid chromatography (HPLC)-size exclusion chromatography (SEC) with a multiple wavelength absorbance detector

High-performance liquid chromatography-size exclusion chromatography (HPLC-SEC) coupled with a multiple wavelength absorbance detector (200-445 nm) was used in this study to investigate the apparent molecular weight (AMW) distributions of dissolved organic matter (DOM). Standard DOM, namely humic acid, fulvic acid and hydrophilic acid, from the Suwannee River were tested to ascertain the performance and sensitivity of the method. In addition to four compounds groups: humic substances (Peak 1, AMW 16 kD), fulvic acids (Peak 2, AMW 11 kD), low AMW acids (Peak 3, AMW 5 kD), and low AMW neutral and amphiphilic molecules, proteins and their amino acid building blocks (Peak 4, AMW 3 kD), an new group that appears to include low AMW, 6-10 kD, humic substances was found based on investigating the spectra at various elution times. The spectroscopic parameter S_>365 (slope at wavelengths >365 nm) was determined to be a good predictor of the AMW of the DOM. The detector wavelength played an important role in evaluating the AMW distribution. For some fractions, such as the humic and low AMW non-aromatic substances, the error in measurement was ±30% as determined by two-dimensional chromatograms detected at an artificially selected wavelength. HPLC-SEC with multiple wavelength absorbance detection was found to be a useful technique for DOM characterization. It characterized the AMW distributions of DOM more accurately and provided additional, potentially important information concerning the properties of DOM with varying AMWs.     

脱硝性能V2O5-WO3-CeO2/TiO2催化剂的制备及其

采用一步浸渍法和分步浸渍法分别制备了V_2O_5-WO_3-CeO_2/TiO_2催化剂,考查了其脱硝性能、抗SO_2中毒性能和脱硝活性稳定性,并通过SEM、EDS、XRD、激光拉曼等技术对催化剂进行了表征。实验结果表明:分步浸渍法制备的催化剂的脱硝活性优于一步浸渍法,且抗SO_2中毒能力更强;在m(V_2O_5)∶m(WO_3)∶m(CeO_2)∶m(TiO_2)=1∶5∶10∶100时催化剂脱硝活性最佳,且具有良好的脱硝活性稳定性。表征结果显示,分步浸渍法与一步浸渍法制备的催化剂晶型结构相差不大,而分步浸渍法制备的催化剂颗粒粒径更小、更均匀,催化剂中Ce、O、V和W元素的含量更高。     

Effects of sludge characteristics on electrical resistance and energy consumption during electro-dewatering process

The increase of electrical resistance (ER) and energy consumption (EC) during the later stage of dewatering is a major problem hindering the development of electro-dewatering (EDW) technology. As the variations of sludge characteristics are significant during the EDW process, the relationships between sludge characteristics and ER and EC during EDW remain unclear. In this study, the effects of moisture content (MC), thickness, pH, conductivity, zeta potential, temperature, and gas volume on the ER and EC during the EDW process were statistically investigated using correlation and multiple linear regression analyses. Herein, the results showed that the ER of the sludge near the anode was primarily affected by pH, whereas the sludge near the cathode was primarily affected by the MC and conductivity. Further, sludge temperature and conductivity were the most reliable indicators to predict the EC near the anode and cathode, respectively. The results of this study provide theoretical guidance useful for solving the increase of ER and EC during the later stage of the EDW process.     

紫外光诱导荧光分析仪结合多元线性回归算法在城市河流常规污染指标监测中的应用

为建立一种针对城市河流水体常规污染指标的快速原位监测方法,首次运用紫外光诱导荧光分析仪对扬州市60条城市河流进行水体三维荧光光谱(EEM)测量,形成了具有多样性的水质样本集合.利用峰值拾取法、相关性分析和主成分分析3种方式从三维荧光光谱中提取溶解性有机物(DOM)污染信息,结合多元线性回归算法(MLR),建立与化学需氧...     

冀中南平原区气溶胶标高变化及估算模型研究

作为反映大气气溶胶垂直分布的重要参量,气溶胶标高被广泛应用于气溶胶反演及模型订正研究中.为研究气溶胶标高时空变化规律并构建其简易计算模型,基于2009～2016年气象站点观测资料及MODIS卫星反演数据,利用Peterson模型及多元回归分析对冀中南平原区气溶胶标高进行了估算分析.研究结果表明:区域气溶胶标高夏季最高,...     

探析资源环境承载力约束下的“多规合一”思路

在我国进一步加强城市治理、大力开展环境与资源保护工作中,提出相关部门需要通力合作,实现"多规合一"的要求。而在"多规合一"中,资源环境承载力及其约束发挥了重要的作用。本文立足于此背景,在阐明资源环境承载力与"多规合一"基本内涵的基础上,结合相关研究资料,重点围绕资源环境承载力约束下的"多规合一"思路进行简要分析研究。