曝气生物滤池在酱油废水深度处理中的应用研究

采用陶粒、活性炭混合填料的曝气生物滤池深度处理酱油废水,在不同的水力负荷条件下,以上向流的运行方式,研究了滤池对COD和色度的去除效果,用生物量(MLVSS)进一步证实了对污染物去除起主要作用的填料层高度范围.结果表明:陶粒与活性炭填装比例3∶1,水力负荷0.75 m/h下,进水COD和色度为126 mg/L和155倍;出水COD和色度为43.8 mg/L和50倍,去除率分别达到了65.2%和68.6%,出水COD和色度优于废水综合排放标准(GB 8978-1996)的一级排放标准.污染物的去除主要发生在填料层0～65 cm高度范围内,微生物量也达到最大.     

曝气生物滤池深度处理部分制药废水的研究

本文以曝气生物滤池深度处理制药废水的二级生化出水.研究了曝气生物滤池的启动及气水比、水力负荷和进水有机物浓度对曝气生物滤池CODCr去除率的影响,并最终选出一种最优质高效的生物滤料.试验结果表明,CODCr去除率与水力负荷和气水比并不是简单的线性关系.在气水比为15,水力停留时间为4 h时,CODCr去除率最大.进水有机物质量浓度处于323～1 021 mg/L范围内,CODCr去除率随进水有机物质量浓度的增加而增加.     

粉煤灰陶粒在曝气生物滤池中挂膜启动及运行探讨

以粉煤灰为主要原料,制备水处理用陶粒。以粉煤灰陶粒作为曝气生物滤池的滤料,对城市污水二级出水中的COD,氨氮进一步去除。实验反应器正常运行阶段,COD平均去除率为70%,氨氮平均去除率为75%。在水力停留时间为1 h,气水比为4∶1时,水处理效益最好。在短时间停止供流的情况下,系统可快速恢复其水处理能力。     

基于PLC控制的内循环回流式流化床反应器的设计

针对传统反应器在有机废水处理中存在的问题,在结合UASB和IC反应器特点的基础上,通过设置布水器进行均衡布水,引进固定化微生物填料防止反应器堵塞,改进三相分离器提高回流比,设置内循环回流管减少水头损失及布置多级取样口方便采样,设计可自动控制的厌氧/好氧一体化内循环回流式流化床反应器,并且采用PLC控制器控制进出水水量、水流上升速度、曝气量、进气时间及水力停留时间等参数,用于处理高氨氮有机废水.屠宰废水室内试验结果表明:在进水流量为1 m3/d,水力停留时间为3h,pH值7.2,25℃的条件下,好氧微曝气使溶解氧为2 mg/L,厌氧好氧自动交替运行,水流上升速控制在约1.0 m/h,约40％的污水无动力回流处理,填料无堵塞,采样方便.经50d驯化后,出水CODcr、NH+4-N、油脂及色度的去除率分别达到了87％、63.6％、74.7％和84.7％,且每天能获得生物质气体约0.32 m,平均处理费用为0.15元/t,比传统处理工艺费用要低.这说明内循环回流式流化床反应器较传统反应器在高氨氮有机废水处理,特别是脱氮方面有较大提高,可用于高氨氮有机废水的处理.     

曝气生物滤池内的短程硝化研究

以曝气生物滤池为载体,研究了NH4 -N浓度、pH、FA、DO对曝气生物滤池内NO2--N积累的影响及沿滤池高度NO2--N积累情况.试验表明,在一定的条件下,曝气生物滤池内发生了同步硝化反硝化和短程硝化反硝化,且在某高度处可以实现较高的氨氮去除率和NO2--N积累率.     

滤料对城镇污水曝气生物滤池工程设计及运行的影响

详细阐述了滤料的理化性质,如孔隙率、孔隙大小、亲水性、粒径、滤层高度等对曝气生物滤池运行效果的影响,在此基础上,提出了城镇污水处理中不同功能曝气生物滤池滤料的选型原则及设计参数,以期能够为规范和推广城镇污水曝气生物滤池的工程应用提供参考.     

新型多级跌水曝气生物滤池的运行效能研究

本文研究了在"跌水曝气式生物滤塔"专利(专利号201020207090.9)基础上增设电气石纤维滤料层的多级跌水曝气生物滤池的运行效能,从水力负荷和容积负荷两方面证明改造后的多级曝气生物滤池处理低浓度生活有机污水的有效性和负离子材料对滤料层净化效率的改进效果,为类似多级跌水曝气生物滤池的工艺设计提供了参考依据。     

复合曝气生物滤池处理微污染源水的试验研究

采用复合曝气生物滤池工艺(生物活性炭BAC+曝气生物滤池BAF)将常规生化过滤、活性炭吸附与生物膜氧化技术相结合,对微污染源水处理进行试验研究,以期为其工程应用提供理论依据.结果表明,在源水为Ⅳ类水的情况下,复合BAF反应器对水中CODMn和UV254的平均去除率分别为25.8%和18.4%,对NH3-N及浊度的平均去除率分别为86.2%和53.6%.复合曝气生物滤池工艺作为微污染源水的预处理净水设施能有效改善饮用水处理水质.在进一步进行其他几项水质指标的试验研究以及优化运行参数后可应用于工程实践.     

水力停留时间对水解酸化-改性贻贝壳填料曝气生物滤池处理模拟生活污水的影响

研究了水力停留时间(HRT)对以贻贝壳和3种不同质量分数柠檬酸改性的贻贝壳为填料的曝气生物滤池(BAF)与水解酸化池组合对模拟生活污水中COD、氨氮(NH3-N)和总磷(TP)去除效果的影响,并对4个系统的处理效果进行比较,以考察贻贝壳改性程度对系统处理效果的影响。结果表明,贻贝壳及改性贻贝壳均可以作为BAF的填料,其中0.5%柠檬酸改性的贻贝壳填料处理系统对模拟生活污水的处理效率最高。HRT对COD和TP去除效果的影响较大;HRT为4 h或8 h时,4个系统对NH3-N的平均去除率均在92.30%以上。     

不同填料生物反应器中脱氮微生物群落比较分析

为比较填充不同填料(悬浮填料和弹性填料)生物反应器的抗冲击负荷能力,研究了不同水力停留时间(14.80 h、11.90 h、9.89 h和7.99 h)下两组反应器的处理性能及附着生物膜的特性,通过提取基因组DNA,采用PCR扩增与高通量测序技术对水力停留时间为7.99 h工况下两者菌群测序并进行了操作单元(OTU)聚类分析、多样性分析和分类学分析。结果表明,不同水力停留时间下弹性填料附着的生物膜量和胞外多聚物(EPS)质量比均高于悬浮填料,生物膜结构较为稳定;弹性填料和悬浮填料富集微生物菌群的高通量测序分析均得到优化序列23 129条,测序覆盖深度都在99%左右,经过97%相似度归并后分别得到375个OTUs和307个OTUs,与悬浮填料相比,弹性填料附着的生物膜内硝化菌和反硝化菌丰度均较高,这在一定程度上表明弹性填料在处理污染河水时具有较强的抗冲击负荷能力。     

基于遗传算法的支持向量机预测有机物自燃点的研究

根据定量构效关系(QSPR)原理,研究自燃点(AIT)与其分子结构间的内在定量关系。以265种有机化合物作为样本集,随机选择238种作为训练集,27种作为测试集,用遗传算法(GA)进行变量选择,分别建立多元线性回归(MLR)模型和支持向量机(SVM)模型研究有机物的自燃点与其分子结构间的关系。通过分析,发现造成模型预测效果不佳的原因是试验数据本身存在问题。通过对2个模型的比较,结果为GA-SVM模型明显优于GA-MLR模型,说明自燃点与其分子结构间具有很强的非线性关系。     

Influence of ATD versus PMHS reference sensor inputs on computational brain response in frontal impacts to advanced combat helmet (ACH)

ABSTRACT

Objective: This study analyzed the influence of reference sensor inputs from anthropomorphic test devices (ATDs) versus postmortem human subjects (PMHSs) on simulations of frontal blunt impacts to the advanced combat helmet (ACH).

Methods: A rigid-arm pendulum was used to generate frontal impacts to ACHs mounted on ATDs and PMHS. An appropriately sized ACH was selected according to standard fitting guidelines. The National Operating Committee on Standards for Athletic Equipment (NOCSAE) head was selected for ATD tests due to shape features that enabled a realistic helmet fit. A custom procedure was used to mount a reference sensor internally near the center of gravity (CG) of the PMHS. Reference sensor data from the head CG were used as inputs for the Simulated Injury Monitor (SIMon). Brain responses were assessed with the cumulative strain damage measure set at 10%, or CSDM(10).

Results: Compared to ATD tests, PMHS tests produced 18.7% higher peak linear accelerations and 5.2% higher peak angular velocities. Average times to peak for linear accelerations were relatively similar between ATDs (5.5?ms) and PMHSs (5.8?ms). However, times to peak for angular velocities were higher by a factor of up to 3.4 for PMHSs compared to ATDs. Values for were also higher by a factor of up to 13.1 when PMHS inputs were used for SIMon.

Conclusions: The preliminary findings of this work indicate that small differences in ATD versus PMHS head kinematics could lead to large differences in strain-derived brain injury metrics such as CSDM.     

引气剂和聚丙烯纤维对高水材料性质的影响研究

为了改变高水材料的破坏特点,采用引气剂和聚丙烯纤维双掺对其进行改性。试验结果表明:随着引气剂掺量的增加,浆体的流动性逐渐降低,混合浆液失流时间延长,试块密度和单轴抗压强度逐渐减小;聚丙烯纤维的掺入,对浆体流动性、失流时间、引气率影响均较小。聚丙烯纤维最佳掺量为2 kg/m3,引气剂和聚丙烯纤维的掺入使硬化体的弹性模量略有减小,且使试块由脆性破坏转变为延性破坏,在保持整体不散的情况下,提高其压缩量。SEM观察表明:钙矾石在气泡壁上集中生成,聚丙烯纤维与基体的界面处有利于针状钙矾石的生成,从而使聚丙烯纤维更好地发挥增强增韧的作用。     

Nonlinear molecular based modeling of the flash point for application in inherently safer design

New chemical process design strategies utilizing computer-aided molecular design (CAMD) can provide significant improvements in process safety by designing chemicals with required target properties and the substitution of safer chemicals. An important aspect of this methodology concerns the prediction of properties given the molecular structure. This study utilizes one such emerging method for prediction of a hazardous property, flash point (FP), which is in the center of attention in safety studies. Using such a reliable data set comprising 1651 organic and inorganic chemicals, from 79 diverse material classes, and robust dynamic binary particle swarm optimization for the feature selection step resulted in the most efficient molecular features of the FP investigations. Apart from the simple yet precise five-parameter multivariate model, the FP nonlinear behavior was thoroughly investigated by a novel hybrid of particle swarm optimization and support vector regression. Besides, 195 missing experimental FPs of the DIPPR data set are predicted via the presented procedure.     

Automation design in advanced control rooms of the modernized nuclear power plants

This study evaluated the effects of levels of automation (LOAs) decisions in advanced control rooms of the modernized nuclear power plants. Following advancements in design of digitalized human–system interfaces (HSIs), the roles of human operators have changed significantly. Negative performance and safety consequences may occur as a result of these changes. These problems are viewed as the out-of-the-loop (OOTL) performance problems. This study conducted an experiment to compare the effects of different LOAs under different operating procedures on operating performance. Experimental results indicated that blended decision-making (level 6 LOA) generates the lowest mental workload. Furthermore, the pattern of SA observed in this study is found better SA at intermediate LOA and poorer SA at low level of automation and full automation. Subjective rating results suggest that LOAs distribute the roles of option generation, and selection between human and/or computer servers which significantly impacts automated system performance. This study provides a direction for the HSI designers in nuclear power plants (NPPs). Additionally, based on results obtained by this study, the user interfaces of PCTRAN system and the alarm reset system should be improved to ensure safe operation of NPPs.     

A comparative study on the autoxidation of dimethyl ether (DME) comparison with diethyl ether (DEE) and diisopropyl ether (DIPE)

The Japanese government is planning to introduce DME as a substituted energy for oil and LNG. Introduction of DME could contribute greatly to both the prevention of global warming and the formation of resource-recycling societies. In these circumstances, a safety assessment of DME is very important when DME is used on a large scale. There is a possibility that prolonged exposure in air induces autoxidation to produce explosive organic peroxides during transportation and storage of DME. Therefore, the reactivity of DME with oxygen and the mechanism of the autoxidation were investigated. Accelerating Rate Calorimetry (ARC) was used to evaluate the thermal stability of DME and DIPE, a known peroxide producers, under adiabatic and various atmospheric conditions. In ARC studies of DME under oxygen, exothermic decompositions were detected although its self-heating rate was low in comparison with DIPE. Oven storage tests were carried out and iodimetry was used to measure the concentration of peroxides produced from DME in comparison with DIPE and DEE. However, no products could be found for DME either by GC/MS or by iodimetry, while some evidence of autoxidation of both DEE and DIPE were obtained from these experiments.     

单板层积梁弯曲破坏的试验研究与分析

在万能力学试验机上测试由高频热压方法制造的桦木和椴木单板层积梁的密度、静曲强度(MOR)、弹性模量(MOE)和水平剪切强度等力学性质;讨论LVL(单板层积材)梁受弯曲、水平剪切载荷时的主要破坏形式并得出相关结论。测试结果表明,在该试验条件下,桦木和椴木LVL梁具有较大的密度、MOR和较高的MOE。其主要物理力学性能受树种的影响较大,桦木LVL梁的主要性能均优于椴木LVL梁。当LVL梁受弯曲破坏时,其主要破坏形式为整体断裂破坏、开裂破坏以及混合破坏等3种;受水平剪切应力破坏时,以基材剪切破坏和胶层剪切破坏两种形式为主。     

基于案例推理的大型养路机械故障诊断系统

为实现铁路大型养路机械(简称"大机")故障的智能检索和诊断,使用基于案例推理(CBR)的思路分析和设计用以实现这些目的的系统。阐述案例的表示和构建方法。提出捣固车的故障案例模型构建方法。设计捣固车故障诊断的CBR系统。给出带权值的k-近邻法的案例相似性检索方法。提出大机故障诊断智能决策系统,采用定性和定量检索相结合的方法。故障诊断系统能够进行案例的定性、定量和混合检索。用捣固车的具体故障案例,验证所设计的系统的可行性。诊断系统检索得到的故障类型与依据现场采集的数据判定的故障类型基本一致,能够进行案例调用和修改。     

ZVI与TCE反应参数优化及动力学方程的建立

以批量研究的方法,考察了ZVI纯度、ZVI粒径、ZVI投量、p H值、温度和初始TCE浓度对TCE去除的影响,建立了ZVI去除TCE的动力学方程。最佳参数为:ZVI纯度92%,ZVI粒径30目,ZVI投量30 g,p H值为6.0,温度25℃,初始TCE质量浓度50 mg/L。最佳条件下TCE去除率可达73.6%,反应符合一级动力学方程。