自催化法合成聚天冬氨酸

以马来酸酐和乙酸铵为原料,在微波条件下用自催化法合成了聚天冬氨酸（PASP）。通过正交实验确定了最佳合成条件：n（乙酸铵）：n（马来酸酐）=1．2,微波功率为1200W,反应时间为10min。在最佳合成条件下,PASP的收率为91．6％,PASP的黏均相对分子质量约为1．5×10^4。经红外光谱表征和核磁共振氢谱测试结果表明,PASP的各种主要官能团表现明显。当Ca^2＋质量浓度为250mg／L、PASP加入量为3mg／L时,PASP的阻垢率达到95％,表明PASP具有较好的阻垢性能。     

Risk assessment and prioritisation of contaminated sites on the catchment scale

Contaminated sites pose a significant threat to groundwater resources worldwide. Due to limited available resources a risk-based prioritisation of the remediation efforts is essential. Existing risk assessment tools are unsuitable for this purpose, because they consider each contaminated site separately and on a local scale, which makes it difficult to compare the impact from different sites. Hence a modelling tool for risk assessment of contaminated sites on the catchment scale has been developed. The CatchRisk screening tool evaluates the risk associated with each site in terms of its ability to contaminate abstracted groundwater in the catchment. The tool considers both the local scale and the catchment scale. At the local scale, a flexible, site specific leaching model that can be adjusted to the actual data availability is used to estimate the mass flux over time from identified sites. At the catchment scale, a transport model that utilises the source flux and a groundwater model covering the catchment is used to estimate the transient impact on the supply well. The CatchRisk model was tested on a groundwater catchment for a waterworks north of Copenhagen, Denmark. Even though data scarcity limited the application of the model, the sites that most likely caused the observed contamination at the waterworks were identified. The method was found to be valuable as a basis for prioritising point sources according to their impact on groundwater quality. The tool can also be used as a framework for testing hypotheses on the origin of contamination in the catchment and for identification of unknown contaminant sources.     

Characteristics of the Predator–Prey Interactions and the Horizontal Distribution of Macrozoobenthos in Small Lakes of Different Types

The horizontal distribution and quantitative characteristics of macrozoobenthos were studied in small lakes of the Darwin Nature Reserve (southern Vologda oblast). The aggregation index varied in the open areas of acid lakes, which indicated that communities of small acid water bodies were unstable. The aggregation was the lowest in the open area of a neutral lake. In acid lakes, the number and biomass of macroinvertebrates were the highest near the coasts. In the neutral lake, conversely, these values were maximum in open areas and low near the coast due to a strong pressure of predatory invertebrates and fish. An aggregating effect of invertebrate predators was observed near the coasts of lakes of different types.     

铁路中小站段污水排放规律及处理匹配技术研究

随着铁路通车里程的增长,铁路中小站段随之增加。但是大部分站段污水经过简单处理或不经处理排放,造成了环境的污染。通过对沈阳铁路局下属中小站站段调研,找出典型站段污水排放规律,并提出与之相匹配的污水处理技术。     

高铁酸钾氧化去除弱碱性地下水中低浓度石油类污染物实验研究

研究一般地下水弱碱性水溶液中,高铁酸钾对低浓度石油烃类污染物的氧化去除率.采用0#柴油模拟石油类污染物试验水样,氧化反应在200mL烧杯中模拟完全混合状态完成.实验分析浓度分别为5.02mg/L、2.05mg/L、1.01mg/L和0.52mg/L4个水样石油类污染物氧化去除率.实验研究显示,石油类污染浓度与高铁酸钾浓...     

基于GM-SVR的小样本条件下化工设备可靠性预测

为了准确预测化工设备可靠性趋势，针对化工设备失效寿命数据为小样本的情形，基于灰色估计法与支持向量回归机在小样本数据处理中的优势，建立了失效寿命时间服从三参数威布尔分布的化工设备可靠性模型；结合GM（1，1）和SVR对模型进行参数估计，在压缩机可靠性分析中进行了实例应用，对比分析了最小二乘法、灰色估计法和GM-SVR的估计效果。研究结果表明:GM-SVR对威布尔分布参数的估计精度明显优于最小二乘法和灰色估计法，可以有效地应用于化工设备失效数据为小样本时的可靠性预测。     

农村污染防治工作已迫在眉睫

针对目前农村经济发展过程中出现的主要环境问题,结合农村的实际情况,提出了解决农村环境污染问题的几项措施。并着重分析了规模化畜禽养殖业中的环境污染问题,提出了综合防治对策。     

A Multi‐Scale Analysis of Single‐Family Residential Water Use in the Phoenix Metropolitan Area

Studies that evaluate determinants of residential water demand typically use data from a single spatial scale. Although household‐scale data are preferred, especially when econometric models are used, researchers may be limited to aggregate data. There is little, if any, empirical analysis to assess whether spatial scale may lead to ecological fallacy problems in residential water use research. Using linear mixed‐effects models, we compare the results for the relationship of single‐family water use with its determinants using data from the household and census tract scales in the city of Phoenix. Model results between the household and census tract scale are similar suggesting the ecological fallacy may not be significant. Common significant determinants on these two spatial scales include household size, household income, house age, pool size, irrigable lot size, precipitation, and temperature. We also use city/town scale data from the Phoenix metropolitan area to parameterize the linear mixed‐effects model. The difference in the parameter estimates of those common variables compared to the first two scales indicates there is spatial heterogeneity in the relationship between single‐family water use and its determinants among cities and towns. The negative relationship between single‐family house density and residential water use suggests that residential water consumption could be reduced through coordination of land use planning and water demand management.     

基于石墨烯构建的电化学传感器在环境监测中的应用

综述了基于石墨烯构建的电化学传感器在重金属、有毒气体、农药残留、酚类有机污染物等对环境造成一定危害的物质检测中的应用,并展望了石墨烯电化学传感器在环境监测领域中的发展。     

高负荷活性污泥法应用于中小城市污水处理的研究

针对目前二级城市污水处理厂工程投资高、运行费用高的特点,提出适合中小城市污水处理的工艺——高负荷活性污泥法（HAS）。该工艺不设初次沉淀池,负荷高,泥龄短,污泥沉降性能良好,不存在污泥膨胀,对有机物的去除以絮凝、吸附、沉淀作用为主,对COD、BOD,、SS都有较高的去除效果,对氮、磷有一定的去除作用,出水水质可满足《农田灌溉水质标准》的要求。