遗传投影寻踪回归在城市环境质量评价中的应用

引入投影降维的思想,将遗传投影寻踪与回归分析技术运用到城市环境质量评价中。将此技术与神经网络方法进行实例比较,投影寻踪回归方法不但可以合理地作出环境质量的综合评价,而且消除了神经网络方法中类别判断不够精确的影响。     

Temporal and Spatial Variability of Water Supply Stress in the Haihe River Basin,Northern China1

Ji, Yuhe, Liding Chen, and Ranhao Sun, 2012. Temporal and Spatial Variability of Water Supply Stress in the Haihe River Basin, Northern China. Journal of the American Water Resources Association (JAWRA) 48(5): 999‐1007. DOI: 10.1111/j.1752‐1688.2012.00671.x Abstract: Water resources are becoming increasingly stressed under the influence of climate change and population growth in the Haihe River Basin, Northern China. Assessing the temporal and spatial variability of water supply stress is urgently needed to mitigate water crisis caused by water resource reallocation. Water supply and use data were compiled for the time period of 1998‐2003 in this synthesis study. The Water Supply Stress Index (WSSI) as defined as Water Demand/Water Supply was used to quantitate whether water supply could meet the demand of human activities across the study region. We found a large spatial gradient of water supply stress in the study region, being much higher in the eastern subbasins (ranging from 2.56 to 4.31) than the west subbasins (ranging from 0.56 to 1.92). The eastern plain region not only suffered more serious water supply stress but also had a much higher interannual variability than the western hilly region. The uneven spatial distribution of water supply stress might result from the distribution of land use, population, and climate. Future climate change and rapid economic development are likely to aggravate the existing water crisis in the study region.     

蚯蚓生态滤池中蚯蚓与植物对污水净化的作用评估

构建具有不同蚯蚓和植物配置的4个单级蚯蚓生态滤池,依次编号为A(无蚯蚓无植物)、B(有蚯蚓无植物)、C(有蚯蚓栽种芦苇)和D(有蚯蚓栽种水生鸢尾)。通过比较4个滤池在6个月实验期间对化学需氧量(COD)和总氮(TN)的去除效率,系统分析蚯蚓和植物对滤池去除污染物的影响。实验分2个阶段进行:5月上旬至9月上旬,滤池进水碳氮比恒定为6;9月中旬至11月中旬,滤池每周进水碳氮比交替为3、6、9。研究结果表明,蚯蚓对滤池去除COD有一定的促进作用,且作用强度显著受到进水碳氮比的影响。植物的存在与种类对滤池去除COD效率没有显著影响。蚯蚓和植物对滤池的TN去除效率都没有显著影响。滤池进水的碳氮比是显著影响滤池去除TN效率的主要因素。     

O3-H2O2氧化法处理印染废水

采用O₃-H₂O₂氧化法对印染废水进行氧化处理,比较了O₃氧化法和O₃-H₂O₂氧化法对印染废水的处理效果,考察了初始废水pH、H₂O₂加入量、O₃流量和反应时间对废水的色度去除率和COD去除率的影响。实验结果表明：O₃-H₂O₂氧化法对废水的COD和色度的去除效果比O₃氧化法更好;在初始废水pH为11、H₂O₂加入量为13mmol/L、O₃流量为6g/h、反应时间为60min的最佳工艺条件下,处理后废水COD为61.50mg/L,COD去除率为95.73%,废水色度为5倍,色度去除率为99.75%,TOC为37.84mg/L,TOC去除率为85.10%,BOD₅为22.76mg/L,BOD₅去除率为90.20%,BOD₅/COD为0.37。     

基于SARIMA模型的黑龙江省冰雪旅游国际需求预测

选取黑龙江省1990-2011年冰雪旅游入境人次的月度时间序列为研究样本,建立SARIMA模型对黑龙江省冰雪旅游国际需求进行分析预测。结果表明,SARIMA（4,1,4）（1,1,1）。模型的拟合度和短期预测效果都较好。通过应用SARIMA模型进行冰雪旅游预测,以期对黑龙江省旅游企业的冰雪旅游国际客源市场开发及政府部门制定冰雪旅游发展战略和政策调整提供重要的理论依据。     

Toxicological characterization of the landfill leachate prior/after chemical and electrochemical treatment: A study on human and plant cells

In this research, toxicological safety of two newly developed methods for the treatment of landfill leachate from the Piškornica (Croatia) sanitary landfill was investigated. Chemical treatment procedure combined chemical precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite. Electrochemical treatment approach included pretreatment with ozone followed by electrooxidation/electrocoagulation and final polishing by microwave irradiation. Cell viability of untreated/treated landfill leachate was examined using fluorescence microscopy. Cytotoxic effect of the original leachate was obtained for both exposure periods (4 and 24 h) while treated samples showed no cytotoxic effect even after prolonged exposure time. The potential DNA damage of the untreated/treated landfill leachate was evaluated by the comet assay and cytokinesis-block micronucleus (CBMN) assay using either human or plant cells. The original leachate exhibited significantly higher comet assay parameters compared to negative control after 24 h exposure. On the contrary, there was no significant difference between negative control and chemically/electrochemically treated leachate for any of the parameters tested. There was also no significant increase in either CBMN assay parameter compared to the negative control following the exposure of the lymphocytes to the chemically or electrochemically treated landfill leachate for both exposure periods while the original sample showed significantly higher number of micronuclei, nucleoplasmic bridges and nuclear buds for both exposure times. Results suggest that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety of the treated effluent.     

Factors Affecting Sediment Oxygen Demand Dynamics in Blackwater Streams of Georgia’s Coastal Plain1

Abstract: Sediment oxygen demand (SOD) is believed to be an important process affecting dissolved oxygen (DO) concentrations in blackwater streams of the southeastern coastal plain. Because very few data on SOD are available, it is common for modelers to take SOD values from the literature for use with DO models. In this study, SOD was measured in seven blackwater streams of the Suwannee River Basin within the Georgia coastal plain for between August 2004 and April 2005. SOD was measured using four in situ chambers and was found to vary on average between 0.1 and 2.3 g O₂/m/day across the seven study sites throughout the study period. SOD was found to vary significantly between the watersheds within the Suwannee River Basin. However, land use was not found to be the driving force behind SOD values. Statistical analyses did find significant interaction between land use and watersheds suggesting that an intrinsically different factor in each of the watersheds may be affecting SOD and the low DO concentrations. Further research is needed to identify the factors driving SOD dynamics in the blackwater streams of Georgia’s coastal plain. Results from this study will be used by the Georgia Department of Natural Resources – Environmental Protection Division as model input data for the development and evaluation of DO total maximum daily loads in the Georgia coastal plain.     

用海泡石处理采油废水

用海泡石吸附法处理采油废水,考察了处理时间、海泡石加入量和采油废水pH对采油废水COD去除率的影响,并通过正交实验优化了采油废水处理工艺条件。通过正交实验得到的采油废水处理最佳工艺条件为：处理时间6h,粒径为150μm的海泡石加入量200g／L,采油废水pH9。在该条件下处理采油废水,COD去除率达到91％,处理后出水的COD为34．71mg／L,小于GB8978-1996（（污水综合排放标准》中的一级标准（60mg／L）。     

生化需氧量测定的方法改进

生化需氧量测定中接种液的制备和稀释倍数的确定是2个关键的步骤,本文提出一种可行的制备接种液的方法,根据实践经验,总结出一种稀释倍数计算方法,适合在实际分析中使用。     

纳米光催化氧化测定不同水体化学需氧量的研究

采用简便的沉淀法制备的纳米氧化锌为光催化荆,重铬酸钾为光生电子接受体,研究了纳米氧化锌-重铬酸钾体系测定COD的方法.COD值在1～100mg/L之间有良好的线性关系,线性方程为y=0.0007χ 0.0069,相关系数为r=0.9992,检测限为0.66mg,L.采用本方法和CODM.国标法对不同水体样品进行比较测定发现,对低COD值样品本方法加标回收率在96.3%～100.6%之间,变异系数Cv%=1.1～3.4,准确度和精密度均优于CODMn国标法,弥补了低COD值样品国标法(CODmn)测定不准确的不足,且单个样品测定时间短,具有推广应用价值.