Particle properties in granular activated carbon filter during drinking water treatment

The elemental composition and bacteria attached in particles were investigated during granular activated carbon (GAC) filtration.The experimental results showed that trapped influent particles could form new,larger particles on GAC surface.The sloughing of individuals off GAC surface caused an increase in effluent particles in the size range from 5 to 25 μm.The selectivity for element removal in GAC filters caused an increasing proportion of metallic elements in the effluent particles.The distribution of molar ratio indicated a complicated composition for large particles,involving organic and inorganic substances.The organic proportion accounted for 40% of total carbon attached to the particles.Compared with dissolved carbon,there was potential for the formation of trihalomethanes by organic carbon attached to particles,especially for those with size larger than 10 μm.The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 μm.The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection.The residual attached bacteria after chorine disinfection was increased to 10 2-10 3 CFU/mL within 24 hours at 25°C.     

侧流化学磷回收强化生物除磷的模拟预测与试验验证

为了强化污水中生物除磷作用,本研究通过模拟预测与实验室试验验证了厌氧上清液侧流化学磷沉淀与回收对强化生物除磷的促进作用.模拟预测与试验结果表明,在进水COD/P=37.5工况下,当侧流比增加至30%时,通过化学磷沉淀（调节pH＞9.0）可使出水中TP浓度从碳源抑制时的＜6.0 mg·L-1（以P计）下降至≤1.0 mg·L-1（以P计）,同时可回收进水中P负荷的64%.经验证与校正后的TUD数学模型模拟预测有着与试验结果近乎一致的效果.因此,数学模拟技术完全有可能取代中间试验过程而直接将小试结果放大至工程应用.     

基于DCD的“安全—发展”协同治理绩效评估框架探讨

党的十九大提出“统筹发展和安全”的要求,构建相应的“安全—发展”协同治理绩效评估体系成为迫在眉睫的任务。通过运用社会基本矛盾、社会主要矛盾、社会主要矛盾主要方面的理论原理,构建“发展—应急—满意度”(Development-Contingencies-Degree of Satisfaction,DCD)的三角形绩效分析框架,设立经济发展、安全责任制、科学管理、依法行政、公共服务、安全感等一级指标,探讨若干二级和三级指标,构建“安全—发展”协同治理绩效评估指标体系框架,为检验常态与应急态协同绩效治理水平提供尺度。     

Analysis of car-to-bicycle approach patterns for developing active safety devices

Objective: To reduce the severity of injuries and the number of cyclist deaths in traffic accidents, active safety devices providing cyclist detection are considered to be effective countermeasures. The features of car-to-bicycle collisions need to be known in detail to develop such safety devices.

Methods: The study investigated near-miss situations captured by drive recorders installed in passenger cars. Because similarities in the approach patterns between near-miss incidents and real-world fatal cyclist accidents in Japan were confirmed, we analyzed the 229 near-miss incident data via video capturing bicycles crossing the road in front of forward-moving cars. Using a video frame captured by a drive recorder, the time to collision (TTC) was calculated from the car's velocity and the distance between the car and bicycle at the moment when the bicycle initially appeared.

Results: The average TTC in the cases where bicycles emerged from behind obstructions was shorter than that in the cases where drivers had unobstructed views of the bicycles. In comparing the TTC of car-to-bicycle near-miss incidents to the previously obtained results of car-to-pedestrian near-miss incidents, it was determined that the average TTC in car-to-bicycle near-miss incidents was significantly longer than that in car-to-pedestrian near-miss incidents.

Conclusions: When considering the TTC in the test protocol of evaluation for safety performance of active safety devices, we propose individual TTCs for evaluation of cyclist and pedestrian detections, respectively. In the test protocols, the following 2 scenarios should be employed: bicycle emerging from behind an unobstructed view and bicycle emerging from behind obstructions.     

Exploring the association between working memory and driving performance in Parkinson's disease

Objective: The aim of this study was to explore whether varying levels of operational and tactical driving task demand differentially affect drivers with Parkinson's disease (PD) and control drivers in their sign recall.

Methods: Study participants aged between 50 and 70 years included a group of drivers with PD (n = 10) and a group of age- and sex-matched control drivers (n = 10). Their performance in a sign recall task was measured using a driving simulator.

Results: Drivers in the control group performed better than drivers with PD in a sign recall task, but this trend was not statistically significant (P =.43). In addition, regardless of group membership, subjects' performance differed according to varying levels of task demand. Performance in the sign recall task was more likely to drop with increasing task demand (P =.03). This difference was significant when the variation in task demand was associated with a cognitive task; that is, when drivers were required to apply the instructions from working memory.

Conclusions: Although the conclusions drawn from this study are tentative, the evidence presented here is encouraging with regard to the use of a driving simulator to examine isolated cognitive functions underlying driving performance in PD. With an understanding of its limitations, such driving simulation in combination with functional assessment batteries measuring physical, visual, and cognitive abilities could comprise one component of a multitiered system to evaluate medical fitness to drive.     

工业污染产生的经济社会原因分析及治理对策研究

面对经济高速发展带来的工业污染形势,从工业污染问题的结构性问题突出、环境风险隐患大、污染物排放总量大等三大现状入手,对工业污染问题产生的经济和社会原因进行了分析,经济原因主要是追求利益最大化,环保资金投入不足和工业生产的外部不经济性,社会原因主要是环境社会责任感不足和监督体制机制不完善,提出了积极发展循环经济,充分借助市场经济之手和完善行政管控制度的对策,得出了迫切需要加快工业污染治理的结论。     

IWRM视角下污水治理体系问题系统诊断与对策研究——以浙江省为例

基于集成水资源管理理念框架,较系统地构建了污水治理体系问题诊断指标体系并明确了诊断标准.实证研究表明,浙江省污水治理体系仍存在政策不协调,投资结构不合理,体制横向不协调、纵向不到位、职责分散,民主参与决策与监督机制不健全,排污行为监测监管不到位,经济激励不够、行业自律不足等问题.建议浙江省应进一步协调区域发展政策,优化污水治理城乡投融资结构,完善机构设置,优化部门协调,加强政府监测监管等,以提高污水治理绩效.     

政府环境监管与企业最优环境策略的博弈

随着我国经济的快速发展,伴随而来的是日趋严峻的环境污染,而在政府环境监管的背景下,各个利益相关者之间的博弈在环保效果实施中发挥了很大的作用。利用博弈论的分析方法,建立了一个关于中央政府、地方政府和企业三个利益相关者之间的利益博弈模型,通过对该模型的求解得出三方的平衡状态。最后针对如何实现政府高效监管和企业最优环境策略,向博弈三方共同努力推动社会经济可持续发展提供了相关政策建议。     

Waste‐to‐energy recovery potential: A case study at Jaipur railway station

A study was conducted at the Jaipur railway station in Jaipur, India, to give the perspectives of the actual waste management practices there. Required information was collected from the stakeholders by means of semi‐structured questionnaires, individual and group interviews, and recorded, official data regarding waste generation, collection, transportation, and disposal. Further quantitative and compositional analyses were performed by means of surveys and measurements. Field visits were made for collection of waste samples for quantification and for the study of its management. The field data were compiled and analyzed by sorting the waste into different components. It was found that 1.8 tons of solid waste is collected per day, and a considerable percentage of it comprises paper, plastic, and glass. Excluding the inerts, which are irrelevant from the point of view of energy saving and recovery potential, the average moisture content was found to be 3.38%. From the perspective of life cycle analysis, the option of composting or recycling would give savings of 28.33 gigajoules (GJ) per day over landfilling, while combustion would give savings of 2.97 GJ per day in comparison to landfilling. Analysis based on a compositional model gives a heat value of 8,157.87 kilojoules per kilogram, which amounts to 14.68 GJ of energy per day.     

Local governance of greenhouse gas emissions from air travel

Global greenhouse gas emissions from air travel (GHG-A) are on the rise, and projections point towards a rapid growth in the coming decades. This study aims to examine how local government (cities), addresses GHG-A in their Sustainable Energy Action Plans (SEAP). To fulfil this aim, over 200 SEAPs were analysed focusing on three issues: (1) Treatment of GHG-A in local emissions inventories; (2) Policy initiatives within this domain; and (3) The cities’ perceptions of the conflicts of interests. Results showed that more than half of the cities acknowledge the challenge of GHG-A, around one third include GHG-A in their emissions inventories, and more than one quarter have initiated policy interventions. To categorise these interventions, we have added a mode ‘governing by agenda setting’ to an existing analytical framework, ‘Modes of governing’. With their authority limited to the local setting, this mode of governing is a common channel for cities to push changes at higher levels.