城市合流污水A２/O处理系统中TTC ETS活性监测研究

研究了温度和F/M的变化对A^２/O系统TTCETS活性的影响,分析了TTCETS活性与COD降解的相关关系;通过低C/N冲击下TTCETS活性和理化指标的比较,讨论了以TTCETS活性表征系统运行状况的优劣.结果表明,一定范围内,温度与F/M均与TTCETS活性成正相关,TTCETS活性(TF/TSS·t)变化范围约13.2～48.3 mg/(g·h),最大值约为60 mg/(g·h);TTCETS活性与COD去除率相关性显著,并且TTCETS活性可预警系统的异常状态,当TTCETS活性为41.0 mg/(g·h)时,COD去除效率最高.     

西部管道工程HSE一体化绩效管理应用研究

分析了我国管道工程项目HSE绩效管理存在问题,运用绩效管理理论,结合“PMT（业主）＋PMC（监理）＋EPC（施工总承包方）”一体化模式及西部管道工程,阐述了HSE一体化绩效管理体系的建立及应用情况。     

Error Assessment for Height Above the Nearest Drainage Inundation Mapping

Real‐time flood inundation mapping is vital for emergency response to help protect life and property. Inundation mapping transforms rainfall forecasts into meaningful spatial information that can be utilized before, during, and after disasters. While inundation mapping has traditionally been conducted on a local scale, automated algorithms using topography data can be utilized to efficiently produce flood maps across the continental scale. The Height Above the Nearest Drainage method can be used in conjunction with synthetic rating curves (SRCs) to produce inundation maps, but the performance of these inundation maps needs to be assessed. Here we assess the accuracy of the SRCs and calculate statistics for comparing the SRCs to rating curves obtained from hydrodynamic models calibrated against observed stage heights. We find SRCs are accurate enough for large‐scale approximate inundation mapping while not as accurate when assessing individual reaches or cross sections. We investigate the effect of terrain and channel characteristics and observe reach length and slope predict divergence between the two types of rating curves, and SRCs perform poorly for short reaches with extreme slope values. We propose an approach to recalculate the slope in Manning’s equation as the weighted average over a minimum distance and assess accuracy for a range of moving window lengths.     

改性兰炭末对硝基苯生产废水的吸附处理

采用H_2O_2溶液对兰炭末进行改性,并将改性后的兰炭末用于硝基苯生产废水(COD为560 mg/L)的吸附处理。对改性前后的兰炭末进行了表征,考察了吸附效果的影响因素,并对吸附前后改性兰炭末的燃烧热进行了测定。表征结果显示,兰炭末经改性后比表面积和孔径均增大。实验结果表明:在改性兰炭末投加量为0.2 g/m L、吸附时间为180 min、吸附温度为30℃的条件下,废水的COD去除率为93.4%,处理出水达到GB 8978—1996《污水综合排放标准》中规定的排放标准;改性兰炭末对废水中COD的吸附过程符合准二级动力学方程和Freundlich等温吸附模型;吸附后的改性兰炭末燃烧热值增大。     

Study of nitrogen oxide absorption in the calcium sulfite slurry

Experiments were conducted using a bubbling reactor to investigate nitrogen oxide absorption in the calcium sulfite slurry. The effects of CaSO₃ concentration, NO₂/NO mole ratio and O₂ concentrations on NO₂ and SO₂ absorption efficiencies were investigated. Five types of additives, including MgSO₄, Na₂SO₄, FeSO₄, MgSO₄/Na₂SO₄ and FeSO₄/Na₂SO₄, had been evaluated for enhancing NO₂ absorption in CaSO₃ slurry. Results showed that CaSO₃ concentration had significant impact on NO₂ and SO₂ absorption efficiencies, and the highest absorption efficiencies of SO₂ and NO₂ could reach about 99.5 and 75.0 %, respectively. Furthermore, the NO₂ absorption was closely related to the NO₂/NO mole ratio, and the existence of NO₂ in flue gas may promote NO absorption. The presence of O₂ in simulated flue gas was disadvantage for NO _x removal because it can oxidize sulfite to sulfate. It was worth pointing out that FeSO₄/Na₂SO₄ was the best additive among those investigated additives, as the NO₂ removal efficiency was significantly increased from 74.8 to 95.0 %. IC and in situ FTIR results suggest that the main products were NO₃ ^? and NO₂ ^? in liquid phase and N₂O, N₂O₅ and HNO₃ in gas phase during the CaSO₃ absorption process.     

Motorcycle safety among motorcycle taxi drivers and nonoccupational motorcyclists in developing countries: A case study of Maoming,South China

Objective: An increasing number of motorcycle taxis have been involved in traffic crashes in many developing countries. This study examines the characteristics of both motorcycle taxi drivers and nonoccupational motorcyclists, investigates the risks they pose to road safety, and provides recommendations to minimize their risks.

Methods: Based on the data collected from a questionnaire survey of 867 motorcycle taxi drivers and 2,029 nonoccupational motorcyclists in Maoming, South China, comparisons were made to analyze differences of personal attributes, attitudes toward road safety, and self-reported behavior of the 2 groups.

Results: Results of the chi-square tests show that not only motorcycle taxi drivers but also nonoccupational motorcyclists in Maoming held poor attitudes toward road safety and both groups reported unsafe driving behavior. There is much room for improving local road safety education among all motorcyclists in Maoming. Yet, motorcycle taxi drivers were more likely to pose road safety risks than nonoccupational motorcyclists under some circumstances, such as speeding late at night or early in the morning, not requiring passengers to wear helmets, and running a red light. The results of the binary logistic regression model show that possessing a vehicle license for a motorcycle or not was the common significant predictor for unsafe driving behavior of motorcycle taxi drivers and nonoccupational motorcyclists. Therefore, enforcement against all motorcyclists not showing vehicle licenses for their motorcycles should be stepped up.

Conclusion: Motorcycle safety is largely poor in Maoming. Therefore, efforts to improve motorcycle safety should be strengthened by targeting not only motorcycle taxi drivers but also nonoccupational motorcyclists.     

一维碳纳米管与金属氧化物材料研究

一维纳米结构是最吸引人的功能材料而被广泛关注.一维形态可以很容易地提高纳米结构的独特性能,使它们适合各种各样的应用程序,包括气体传感器、电致变色的设备、发光二极管、场发射器、超级电容器和纳米发电机.因此,目前已合成多种一维纳米结构形式的纳米棒、纳米线、纳米管、纳米带等.本文主要介绍了一维碳纳米管与金属氧化物的性质与研究现状,探讨两种材料的优缺点以期进行互补修饰合成新型复合材料.     

Bacterial communities in different locations, seasons and segments of a dairy wastewater treatment system consisting of six segments

A dairy wastewater treatment system composed of the 1st segment (no aeration) equipped with a facility for the destruction of milk fat particles, four successive aerobic treatment segments with activated sludge and a final sludge settlement segment was developed. The activated sludge is circulated through the six segments by settling sediments (activated sludge) in the 6th segment and sending the sediments beck to the 1st and 2nd segments. Microbiota was examined using samples from the non-aerated 1st and aerated 2nd segments obtained from two farms using the same system in summer or winter. Principal component analysis showed that the change in microbiota from the 1st to 2nd segments concomitant with effective wastewater treatment is affected by the concentrations of activated sludge and organic matter (biological oxygen demand [BOD]), and dissolved oxygen (DO) content. Microbiota from five segments (1st and four successive aerobic segments) in one location was also examined. Although the activated sludge is circulating throughout all the segments, microbiota fluctuation was observed. The observed successive changes in microbiota reflected the changes in the concentrations of organic matter and other physicochemical conditions (such as DO), suggesting that the microbiota is flexibly changeable depending on the environmental condition in the segments. The genera Dechloromonas, Zoogloea and Leptothrix are frequently observed in this wastewater treatment system throughout the analyses of microbiota in this study.     

粉煤灰-铝土矿改性制备铝铁复合混凝剂的除磷性能及混凝机理研究

化学混凝法是城市污水处理深度除磷的有效方法,目前常用混凝剂主要存在成本高、除磷效率低且用量大等缺点.本研究采用常压酸浸法,以低成本的铝土矿和粉煤灰为主要原料制备无机复合混凝剂,并对其进行除磷应用及机理研究,结果表明:1自制混凝剂对生活污水中TP去除率达99.58%,出水TP含量为0.012 mg·L-1,优于GB18918—2002一级A标准.2 X-射线衍射和红外光谱结果显示,混凝剂中的Fe—OH、Al—OH、H—OH等基团能与水中的磷酸根作用生成沉淀达到除磷目的,该沉淀在沉降过程中还能吸附不易沉淀的含磷悬浮物,发挥网捕卷扫作用.3采用Ferron逐时络合比色法分析铝铁形态结果显示,混凝剂含有64.14%低聚态铝铁,能中和水中胶体的表面电荷致使胶体脱稳;11.27%中聚态铝铁可吸附在胶体表面,降低其表面电荷,同时以较高的分子量发挥吸附架桥作用;24.59%高聚态铝铁在沉淀过程中可包夹部分胶体粒子,以较大表面积发挥卷扫作用.4分形维数研究结果显示,絮体分形维数在1.2~2.8之间,分形特征较好,能有效发挥絮体的吸附架桥作用.5 Zeta电位分析结果显示,混凝剂本身带正电荷,能与水中带负电荷的胶体物质发生中和,从而压缩双电子层,使胶体粒子脱稳而从水中去除.混凝剂除磷过程是压缩双电层、电中和、吸附架桥和网捕卷扫多种机制共同作用的动态变化过程.     

南宁市区交通环境空气颗粒物中碳组分的污染特征分析研究

含碳颗粒物是大气颗粒物的重要组成部分,对人体健康产生很大的威胁.分别于2012年夏季及2013年冬季在南宁市选取六条主要交通干道采集了PM10、PM2.5样品,分析测定了其中的碳组分.结果表明,碳组分浓度季节变化明显.碳组分在细颗粒物中占有比重比在可吸入颗粒物中大.存在二次有机碳污染.对8种碳组分丰度分析说明南宁市大气颗粒物中碳组分的主要来源是燃煤、机动车尾气及生物质样品燃烧.