大水量下快速提取悬浮物的方法研究

针对大量水体中悬浮物的提取,提出了一泵三瓶滤网覆盖抽滤法,该方法是在传统滤膜抽滤法的基础上,在滤膜的下面,增设了一张尼龙滤网,滤网的大小刚好覆盖布氏漏斗的抽滤小孔,并采用一台真空泵带动三个抽滤瓶。实践证明,一泵三瓶滤网覆盖抽滤法的抽滤速度是传统抽滤方法的7倍多,并且能够减少在抽滤过程中由于抽滤时间过长而导致的悬浮物的质量损失。因此,该方法能够大大提高抽滤的效率,缩短抽滤的时间,加快实验的进程,对大范围内的水体监测工作具有重要的现实意义。     

过氧化氢酶活性及活性抑制的紫外分光光度测定

在体内实验条件下，测定了鲤鱼肝脏过氧化氢酶的活性。实验结果表明，过氧化氢酶的紫外分光光度法是可靠的，活性抑制结果表明，对－二硝基苯对鲤鱼肝脏过氧化氢酶无有明显的抑制作用。鲤鱼肝脏过氧化氢酶可作为一项指标用于生态毒理学研究。     

可溶性有机质对芘在泥炭和高岭土上吸附和解吸的影响

为掌握可溶性有机质(DOM)对憎水性有机污染物吸附和解吸行为的影响,本研究选取四环多环芳烃——芘作为目标污染物,通过批平衡实验研究了不同分子量组分DOM对芘在泥炭和高岭土上吸附和解吸的影响.结果表明,吸附和解吸数据均可以用Freundlich模型很好地拟合(R2＞0.93).DOM的添加抑制了泥炭对芘的吸附,并且分子量...     

响应面法分析Fenton氧化处理采油废水的过程

采用Fenton氧化对采油废水进行研究,选取双氧水与二价铁离子的摩尔比、初始pH值和反应时间为自变量,以废水的COD去除率为响应值,通过Box-Behnken设计方法进行实验设计,进行了3因素3水平共15个实验点的实验。使用响应面分析法对实验结果进行模拟及分析,建立了响应值与3个自变量的二次多项式方程模型。Fenton氧化的优化工艺条件:n(H2O2):n(Fe2+)=0.8,pH=3.0以及反应时间60 min。在该优化条件下,废水的COD去除率可达72.8%,经实验验证,实际值与模型预测值拟合性好,偏差仅为0.5%。实验结果证实了该模型分析采油废水处理运行参数的准确性。优化工艺后的处理水质COD值完全满足油田废水达标排放的要求。通过总离子色谱图和质谱检索分析原油中的成分变化情况,证实Fenton方法对原油组分的降解效果。     

Biodegradation of phthalate esters by two bacteria strains

In this study two aerobic phthalic acid ester (PAE) degrading bacteria strains, DK4 and O18, were isolated from river sediment and petrochemical sludge, respectively. The two strains were found to rapidly degrade PAE with shorter alkyl-chains such diethyl phthalate (DEP), dipropyl phthalate (DPrP), di-n-butyl phthalate (DBP), benzylbutyl phthalate (BBP) and diphenyl phthalate (DPP) are very easily biodegraded, while PAE with longer alkyl-chains such as dicyclohexyl phthalate (DCP) and dihexyl phthalate (DHP) and di-(2-ethylhexyl) phthalate (DEHP) are poorly degraded. The degradation rates of the eight PAEs were higher for strain DK4 than for strain O18. In the simultaneous presence of strains DK4 and O18, the degradation rates of the eight PAEs examined were enhanced. When the eight PAEs were present simultaneously, degradation rates were also enhanced. We also found that PAE degradation was delayed by the addition of nonylphenol or selected polycyclic aromatic hydrocarbons (PAHs) at a concentration of 1 microg/g in the sediment. The bacteria strains isolated, DK4 and O18, were identified as Sphigomonas sp. and Corynebacterium sp., respectively.     

曝气强度对膜污染的影响

混合液浓度的高低及其粒度分布特性是影响膜生物反应器膜污染的重要因素。在一定污泥浓度下,主要考察了曝气强度对污泥絮体粒度分布的影响,以及不同粒度下的膜污染特性。试验结果表明,曝气强度提高,可以起到减缓污泥颗粒在膜表面的沉积作用,但高的错流流速产生的剪切效应使得污泥颗粒变得琐碎,导致细小胶体粒子和溶解性部分增多,增加了膜孔吸附和堵塞的机会,加剧了膜污染的进程。膜污染速率在曝气强度提高初期阶段迅速降低,接着又随曝气强度增加而缓慢升高,在污泥质量浓度为8 g/L的试验条件下,对应的最适曝气强度为84 m3/(m2.h)。     

Deep learning architecture for air quality predictions

With the rapid development of urbanization and industrialization, many developing countries are suffering from heavy air pollution. Governments and citizens have expressed increasing concern regarding air pollution because it affects human health and sustainable development worldwide. Current air quality prediction methods mainly use shallow models; however, these methods produce unsatisfactory results, which inspired us to investigate methods of predicting air quality based on deep architecture models. In this paper, a novel spatiotemporal deep learning (STDL)-based air quality prediction method that inherently considers spatial and temporal correlations is proposed. A stacked autoencoder (SAE) model is used to extract inherent air quality features, and it is trained in a greedy layer-wise manner. Compared with traditional time series prediction models, our model can predict the air quality of all stations simultaneously and shows the temporal stability in all seasons. Moreover, a comparison with the spatiotemporal artificial neural network (STANN), auto regression moving average (ARMA), and support vector regression (SVR) models demonstrates that the proposed method of performing air quality predictions has a superior performance.     

生物焦炭滴滤塔降解苯乙烯废气的中试启动研究

苯乙烯废气既是一种挥发性有机化合物（VOCs），又属于我国恶臭气体控制的范围之内。其作为一种化工原料和有机溶剂广泛应用于工业生产中。生物法处理有机废气具有运行费用低和没有二次污染等优点。采用焦炭填料滴滤塔对苯乙烯废气的处理进行了中试启动研究。启动过程中，进气浓度范围是50—114mg／m^3，去除率为30％～45％左右，最高可达90％左右。所采用的焦炭填料可以认为是一种环境友好型填料，废弃后可作为燃料，值得推广。     

Identification of agricultural factors for improving sustainable land resource management in northern Thailand: A case study in Chiang Mai Province

This paper aims to identify the land-use factors benefiting sustainable land management in terms of environmental conservation. For evaluating the impacts of land use on the environment, the following parameters were used: chemical fertiliser and pesticide use, land-use structure and diversity. The farmers' income, land tenure and farming scale were selected for their influence on agricultural sustainability. The analysis shows a rapid increase in use of chemical fertiliser and pesticide in the past 40 years, and an observable increase in land-use diversity. The amount of chemical fertiliser used per unit area in large-scale farming was lower than that at small scales, but large-scale farming consumes more pesticide than small-scale farming. A significant negative correlation was observed between the proportions of the holdings possessing land and the holdings using the chemical fertiliser. In order to achieve sustainable agriculture, it is necessary to manage crop systems and land use towards selecting new strains and varieties of crops and fruits with a lower demand for chemical fertiliser and a higher resistance to disease and pests, balancing large- and small-scale farming, and ensuring land tenure and economic incentives.     

Multi-index integrated assessment and analysis of town-sewage treatment priorities in China

Water quality is one of the most serious problems of environment and national sustainable development strategy now facing China. After hard work over the last several decades, urban-sewage treatment in China is now relatively well developed. It now affords mainly higher levels of sewage collection and treatment, as well as pollution-load control. The characteristic rapid urbanization now occurring in China is still increasing and developing dramatically, and involves large numbers of people. However, in towns, sewage treatment infrastructure is inadequate, and a high percentage of the sewage generated there is not effectively collected and treated. The sewage and pollution load of such towns have become the most important reason for environmental water problems in China. To understand the priorities of sewage treatment in such towns, and their spatial distribution in China, we conducted two nationwide investigations of water use and sewage discharge in towns. Based on the integrated analytic hierarchy process (AHP), assessment indices and a framework of town-sewage treatment priorities in China were constructed. Then, we assessed and analyzed the priorities of towns regarding three aspects of sewage treatment: environmental stress, economic capability, and infrastructure. The results showed that the southeast coastal areas and north China had higher demand for sewage treatment than other areas. The demand in eastern and western areas had obvious differences in spatial distribution, but had nearly no differences within those areas. The towns having the greatest demand for high-priority sewage treatment were concentrated in regions with high economic capability and intense water resource utilization.