生物质气化洗焦废水的预处理和微生物降解

为了对生物质气化洗焦废水进行深度处理,达到废水排放标准,采用物理过滤和微生物降解相结合的方法,对洗焦废水的原液进行处理。实验结果表明,用木屑、颗粒活性碳、微生物降解的连续步骤处理生物质气化洗焦废水,可达到理想的生物质气化洗焦废水COD的去除效果。     

综合安全评价(FSA)方法

为提高国际海运安全管理的决策水平,国际海事组织(IMO)接受并倡导由英国海运界提出的综合安全评价(FSA)方法,笔者对FSA方法作了本质性分析和应用性研究。阐述了FSA的由来,5个组成步骤及相互关系和流程,揭示了FSA与风险管理和安全系统工程的渊源;介绍了危险识别的7种工具;对步骤二“风险评估”重点引入了半定量分析方法和定量分析方法,并用集合论观点讨论了事故频率和后果严重度的计算方法;介绍了风险控制方案的“成本与效益评估”的数学模型;归纳了FSA方法的优缺点。指出FSA是一种集风险评价和成本/效益评估于一体,兼顾技术性与经济性,可广泛兼容具体评价方法和普遍适用各类风险评价的框架性方法,但具体应用需要有效整合适用的定性和定量方法。     

Bird species migration ratio in East Asia, Australia, and surrounding islands

Bird migration and its relationship with the contemporary environment have attracted long-term discussion. We calculated the avian migration ratio (the proportion of breeding species that migrate) in the areas from 70°E to 180°E and examined its relationship with the annual ranges of ambient temperature, primary productivity (estimated by the Enhanced Vegetation Index), and precipitation, along with island isolation and elevational range. The avian migration ratio increased with increasing latitude in general but varied greatly between the two hemispheres. Additionally, it showed minimal differences between continents and islands. Our analyses revealed that the seasonality of ambient temperature, which represents the energy expenditure of birds, is the dominant factor in determining bird species migration. Seasonality in primary productivity and other environmental factors play an indirect or limited role in bird species migration. The lower avian migration ratio in the Southern Hemisphere can be attributed to its paleogeographical isolation, stable paleoclimate, and warm contemporary environment. Under current trends of global warming, our findings should lead to further studies of the impact of warming on bird migration.     

六种有机物在亚/超临界水中氧化的反应动力学研究

为了给超临界水氧化设备工业化应用提供指导思路,本文设计制作了一套连续化的超临界水氧化仿工业化装置(压力为24MPa,H2O2过氧量倍数为3倍),选取甲基红、靛红、苯磺酸、对氨基苯磺酸、对二甲氨基苯甲醛、2,4-二硝基苯肼6种芳香烃化合物进行了从亚临界过渡到超临界状态下的水氧化试验,并以总有机碳(TOC)为表征研究了6种化合物的去除效果,以幂指数方程描述了6种化合物从亚临界到超临界的反应动力学参数。结果表明:6种有机物在亚临界至超临界点时间段内,反应物TOC的浓度随时间的变化呈现良好的线性下降趋势,且在亚临界状态下,足够的反应停留时间就能取得较好的TOC去除效果,而在超临界状态下,反应过程十分迅速,在较短的反应时间内也会取得较好的TOC去除效果,但随着反应时间的增加,在几分钟之内,TOC的去除率随时间的变化还是较为明显;6种有机物的反应活化能介于26.2～54.341kJ/mol之间,表明不同结构化合物SCWO反应的温度升高效应不同。     

Fenton氧化法处理有机污染物的降解规律探讨

为了预测新生或缺乏试验数据的含有机污染物废水的治理效果,本文通过试验对Fenton氧化法降解芳烃类、卤代物、杂环类等28种有机污染物的规律进行了研究。结果表明:在Fenton反应初始阶段,氧化反应剧烈,反应过程基本符合一级动力学方程,但随着时间的延长,反应趋于平缓;28种有机污染物色度平均去除率(Rcolor)为80.8±30.3%,TOC平均去除率(RTOC)为39.8±30.3%,约为色度平均去除率的0.44倍;以色度为表征的一级反应动力学常数(Kcolor)均大于对应的以TOC为表征的一级反应动力学常数(KTOC),且色度去除效率更高;Fenton氧化法对不同有机污染物的去除效果有显著差异,分子结构对称性强、水溶性较差的有机污染物如偶氮苯、蒽醌等的降解效果相对较差,而苯酚、苯胺等水溶性较好的有机污染物的降解效果相对较好,表明水溶性是影响有机污染物降解效果的重要因素。     

太湖湖滨带春季悬浮物沉降特征与水体营养盐响应

为研究湖滨带悬浮物沉降过程中水体营养盐时空分布状况,在太湖西岸湖滨带典型区域进行原位沉降实验,计算了沉降量和沉降通量,并对沉降过程中TP、TN、NH+4-N、NO-3-N测定分析.结果表明,太湖西岸湖滨带沉降通量表现为人工芦苇区近岸无植被区自然芦苇区远岸无植被区,平均沉降通量分别为(1 383.40±925.60)、(1 208.67±743.50)、(278.72±142.53)、(245.58±154.25)g·(m2·d)-1,沉降第6 d以后沉降量稳定上升,沉降速率大于分解速率;经过持续15 d野外沉降实验观测,沉降过程中近岸带的TP含量是远岸带的2~3倍,且沉积物捕获器内NH+4-N和NO-3-N含量出现显著的差异(P0.01);沉降量与水体TN和NH+4-N含量呈显著相关(P0.01,n=42),表明沉降量的增加会导致上覆水体TN与NH+4-N含量增加;TN与NH+4-N相关系数为0.84,显示沉降量的增加可能加速氮素不同形态间相互转化,这一现象在当前太湖湖泛治理中应当予以重视.     

Simulation of substrate degradation in composting of sewage sludge

To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k₂₀ (the first-order rate constant at 20 °C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k₂₀, k_20s (first-order rate coefficient of slow fraction of BVS at 20 °C) of the sewage sludge were estimated as 0.082 and 0.015 d^?1, respectively.     

沈阳市环境空气质量统计预报应用及效果评估

基于沈阳市统计预报中逐步回归及简易逐步回归模型,利用2017年环境空气主要污染物自动监测实况数据,采用相关系数、标准化平均偏差等指标检验2种模型的预报效果。结果显示:逐步回归及简易逐步回归模式均能够较好的表征污染变化趋势,2种预报模式预报对AQI均表现出春夏季优于秋冬季特点。逐步回归、简易逐步回归模式24 h预报效果优于48和72 h。其中简易逐步回归模式24 h级别准确率达到67%。     

铁碳微电解法预处理垃圾渗滤液膜滤浓缩液

对垃圾渗滤液膜滤浓缩液采用铁碳微电解法进行预处理,探讨了p H值、反应时间及气液比对COD去除效率的影响。结果表明,当p H值为3、反应时间120 min、气液比10∶1时,COD、TN的去除率分别为79.6%,56.4%;NH3-N由进水的70.9 mg/L上升为77.0 mg/L;预处理效果较好。但是由于铁碳微电解对盐度没有去除效果,影响后续反应进行。如何经济有效地降低含盐量成为今后研究重点。     

Increased risk of preterm delivery among people living near the three oil refineries in Taiwan

The petrochemical and petroleum industries are two of the main sources of industrial air pollution in Taiwan. Data used in this study concern outdoor air pollution and the health of individuals living in communities in close proximity to oil refinery plants. The prevalence of delivery of preterm birth infants was significantly higher in mothers living near the oil refinery plants than in control mothers in Taiwan. After controlling for several possible confounders (including maternal age, season, marital status, maternal education, and infant sex), the adjusted odds ratio was 1.14 (95% CI=1.01-1.28) for delivery of preterm infants for mothers living near oil refinery plants. These data provide further support for the hypothesis that air pollution can affect the outcome of pregnancies.