氯盐阻化剂对煤自燃极限参数影响的试验研究

阻化技术是防治煤自燃的常用技术之一,研究阻化剂对煤自燃极限参数的影响是确定阻化效果的关键.采用程序升温试验,分析气煤和长焰煤的原煤样和经MgCl2、KCl、CaCl2、NaCl 4种阻化剂处理后的煤样耗氧速率和放热强度,并计算自燃极限参数和阻化率.结果表明:氯盐阻化剂可降低煤自燃低温阶段的煤耗氧速率和放热强度;4种阻化剂中对气煤煤样的平均阻化率最高是MgCl2 (63.6％),对长焰煤则是CaCl2 (45.9％),平均阻化率与自燃极限参数变化率呈正相关;气煤经MgCl2处理后自燃极限参数变化率最大,长焰煤经CaCl2阻化处理后的自燃极限参数变化率最大,对于气煤4种阻化剂阻化能力由大到小为MgCl2 KCl、CaCl2、NaCl,对长焰煤则为CaCl2、MgCl2、KCl、NaCl;氯盐阻化剂中MgCl2对气煤自燃极限参数影响最大,阻化效果好,而对长焰煤则为CaCl2.     

SBR法处理高盐肝素废水运行参数优化研究

采用SBR法处理高盐肝素钠生产废水,探讨了曝气时间、进水p H、温度等参数对COD和氨氮降解效果及污泥生长的影响。结果表明,控制曝气时间为10 h、进水p H为7.5、反应温度在26~29℃时,COD和氨氮去除率均能稳定在85%以上;对氨氮去除效果较差的反应器,适当添加K+、Ca2+、Mg2+可以取得一定的改善作用,其中K+对Na+和NH4+双重毒性抑制的拮抗效应最明显;经参数优化后的SBR反应器对不同污泥负荷和盐度负荷具有较好的适应能力,受到冲击后COD和氨氮去除率均能在2~3个运行周期内恢复至90%以上。     

地下式污水厂处理工艺优化工程实例研究

介绍了在全地埋式污水处理厂中具体采用了AAO+深床滤池工艺,采用BioWin软件,基于仿真模拟技术进行工艺比选设计,模拟结果表明,在设计参数相同的条件下,改进多级AO工艺的处理效果明显优于传统AAO工艺,因此,AAO主体工艺确定采用改进多级AO工艺,BAF方案主体工艺采用硝化反硝化生物滤池+反硝化生物滤池的形式;并对各分区水力停留时间、进水分配比例、内回流比和外回流比等参数进行优化,在保证出水水质的前提下,获得了最佳的工艺参数.     

工业锅炉大气污染物源强核算方法的研究

工业锅炉燃料燃烧过程排放的二氧化硫、氮氧化物、烟粉尘已成为中国大气煤烟型污染和复合型污染的重要诱因,其源强的核算对于大气污染防控、改善空气环境有着重要的意义。详细介绍了环境影响评价过程中工业锅炉废气基本参数的换算、现有锅炉大气污染物实测浓度的折算及新建锅炉大气污染物源强的核算方法,归纳了相关参数、排污系数,并对工业锅炉大气污染物源强核算研究的发展作出了展望,可为从事工业锅炉大气污染防治控制的环保工作者提供参考。     

冻融循环作用下岩桥变形破裂及能量转化特征研究*

为研究寒区锁固型岩质边坡的破坏机制,对岩桥试件开展冻融循环试验和单轴压缩试验。以数字图像相关方法为观测手段获得加载过程中的全局应变场,分析冻融循环作用对岩桥变形破裂演化特征的影响。引入能量特征指标,探究冻融岩桥加载过程中的能量耗散和释放规律。研究结果表明:随着冻融循环次数的增加,试件抗压强度和弹性模量逐渐劣化;冻融循环作用未改变最终破坏模式,均表现为剪切裂纹贯穿中部岩桥造成的失稳破坏。冻融循环作用促进应变集中带的出现和扩展,加剧裂隙周边的应变集中程度。随着冻融循环次数的增加,试件储能极限和应变能峰后转化率逐渐降低,说明冻融循环作用减缓能量耗散和释放;试件最终破坏与能量转化密切相关,储能极限和应变能峰后转化率越大,试件脆性破坏越显著。     

Hydro-chemical Survey of Groundwater of Hisar City and Assessment of Defluoridation Methods Used in India

Ground water quality of Hisar city was assessed for its suitability for drinking purposes. Samples collected from the Bore-wells (forms a part of municipal water supply) and handpumps (direct consumption) were analyzed for the various physico-chemical parameters including pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity, sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate. The concentrations of magnesium, sodium, potassium, sulfate and especially of chloride were found moderately higher than the WHO standards for the drinking water. Further a comparison of fluoride (F⁻) levels in groundwater of various cities and towns of Haryana state was performed. The relatively higher concentrations of F⁻ in groundwater of Haryana raise the risk of fluorosis and hence groundwater must be used with proper treatment. Promising defluoridation methods using locally available materials and technologies are discussed for the prevention and control of fluorosis. Data were assessed statistically to find the suitable markers of ground water quality as an aid to monitoring groundwater quality.     

养分(磷)吸收机理模型的应用研究──Ⅱ.模型参数的敏感性分析

采用Claassen的养分吸收机理模型探讨了玉米与大豆幼苗磷吸收过程中的参数敏感性,结果表明：在一般土壤与施肥条件下,玉米与大豆幼苗吸收磷的高度敏感性参数或重要限制因素为根系伸长速率与根半径;在相同土壤供磷条件下,供试大豆幼苗根系的磷摄取能力远低于玉米幼苗根系的磷摄取能力,其原因归结于两者在根系最大养分流Imax与根系伸长速率K两个敏感性参数上的差异;玉米与大豆幼苗磷吸收过程中三种根毛参数的敏感性均较低,这主要与土壤供磷水平较高有关;土壤含水量在玉米幼苗磷吸收过程中表现了极高的敏感性,当土壤含水量降低时,土壤养分供应参数对玉米幼苗磷吸收的敏感性与限制作用均增大。     

Assessing Parameter Uncertainty of a Semi‐Distributed Hydrology Model for a Shallow Aquifer Dominated Environmental System

This paper examines the performance of a semi‐distributed hydrology model (i.e., Soil and Water Assessment Tool [SWAT]) using Sequential Uncertainty FItting (SUFI‐2), generalized likelihood uncertainty estimation (GLUE), parameter solution (ParaSol), and particle swarm optimization (PSO). We applied SWAT to the Waccamaw watershed, a shallow aquifer dominated Coastal Plain watershed in the Southeastern United States (U.S.). The model was calibrated (2003‐2005) and validated (2006‐2007) at two U.S. Geological Survey gaging stations, using significant parameters related to surface hydrology, hydrogeology, hydraulics, and physical properties. SWAT performed best during intervals with wet and normal antecedent conditions with varying sensitivity to effluent channel shape and characteristics. In addition, the calibration of all algorithms depended mostly on Manning's n‐value for the tributary channels as the surface friction resistance factor to generate runoff. SUFI‐2 and PSO simulated the same relative probability distribution tails to those observed at an upstream outlet, while all methods (except ParaSol) exhibited longer tails at a downstream outlet. The ParaSol model exhibited large skewness suggesting a global search algorithm was less capable of characterizing parameter uncertainty. Our findings provide insights regarding parameter sensitivity and uncertainty as well as modeling diagnostic analysis that can improve hydrologic theory and prediction in complex watersheds. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

硝基苯甲酸结构对其在EPDM膜中萃取效果的影响

以3种取代基位置不同的硝基苯甲酸为研究对象,研究了辛醇/水分配系数、溶解度、摩尔体积、分子极化率和偶极矩5种结构参数对硝基苯甲酸在三元乙丙橡胶（EPDM）膜中萃取效果的影响。实验结果表明：EPDM膜对硝基苯甲酸有一定的去除效果,邻、间、对硝基苯甲酸的去除率分别为27.1%、32.4%和41.6%;取代基位置的不同使硝基苯甲酸的去除效果出现差异,其疏水性越强越易在EPDM膜中溶解和渗透;硝基苯甲酸的去除率和透过率与其辛醇/水分配系数和分子极化率正相关,与溶解度负相关;硝基苯甲酸的去除率可用分子极化率和偶极矩两个结构参数进行预测。     

Quantized control settings based tuning of a heaving wave energy converter in irregular seas

The increasing awareness of environmental issues attracts more attention on environmentally friendly energy sources. This leads to increasing research on effective use of renewable energy sources. Among them, wave energy offers a high potential. The wave energy converter systems used for transforming the wave energy into electrical energy have been a main research topic for decades. However, only a few of these systems has been successfully implemented. There seems to be some technical problems one of which is on their control applications. It has been reported that by means of appropriate control implementation, the performance of the wave energy converter system could be improved considerably. In literature, many different control techniques are reported. They appear to be weak due to implementation related restrictions. The present study proposes a novel control technique that is far more practical based on quantization of control settings. Various quantization levels and their effect on system power capture performance are studied. The technique assumes use of realistic off-the-shelf components with realistic features. The proposed method utilizes time-series-analysis technique with online parameter estimation feature. This new method does not require any knowledge of previous or future states of any of the system or sea state parameters, but only the currently available and measurable ones. The approach of the new control technique sets it apart from most of the previously reported ones. Therefore, the proposed technique is not only very much practical but also very much useful in improvement of the system power performance relative to passive techniques.