油气集输联合站火灾爆炸危险分析与事故后果模拟

以某联合站为例,根据油气集输联合站站场功能,将联合站划分为油气处理、储运及污水处理3个单元,对各单元发生火灾爆炸事故的可能条件进行分析,并利用DNV公司的SAFETI软件对事故后果进行模拟计算,根据事故影响范围数据,提出相应的安全措施。     

330MW机组锅炉后墙水平刚性梁振动原因分析及处理

大唐略阳发电有限责任公司1 018t/h锅炉的锅炉平台、扶梯、刚性梁有非常明显的振动,需及时处理,以免长期振动造成对锅炉设备的破坏.通过对锅炉振动原因的分析,从3个方面进行治理,取得了较好效果,对于同类型锅炉的振动具有借鉴作用.     

Variation of spatio-temporal distribution of on-road vehicle emissions based on real-time RFID data

High-resolution vehicular emissions inventories are important for managing vehicular pollution and improving urban air quality. This study developed a vehicular emission inventory with high spatio-temporal resolution in the main urban area of Chongqing, based on real-time traffic data from 820 RFID detectors covering 454 roads, and the differences in spatio-temporal emission characteristics between inner and outer districts were analysed. The result showed that the daily vehicular emission intensities of CO, hydrocarbons, PM_2.5, PM₁₀, and NOx were 30.24, 3.83, 0.18, 0.20, and 8.65 kg/km per day, respectively, in the study area during 2018. The pollutants emission intensities in inner district were higher than those in outer district. Light passenger cars (LPCs) were the main contributors of all-day CO emissions in the inner and outer districts, from which the contributors of NOx emissions were different. Diesel and natural gas buses were major contributors of daytime NOx emissions in inner districts, accounting for 40.40%, but buses and heavy duty trucks (HDTs) were major contributors in outer districts. At nighttime, due to the lifting of truck restrictions and suspension of buses, HDTs become the main NOx contributor in both inner and outer districts, and its three NOx emission peak hours were found, which are different to the peak hours of total NOx emission by all vehicles. Unlike most other cities, bridges and connecting channels are always emission hotspots due to long-time traffic congestion. This knowledge will help fully understand vehicular emissions characteristics and is useful for policymakers to design precise prevention and control measures.     

Characteristics and distribution of microplastics in shoreline sediments of the Yangtze River,main tributaries and lakes in China—From upper reaches to the estuary

Environmental Science and Pollution Research - Microplastics (MPs) pervade the environment and increasingly threaten both natural ecosystems and human health. In this study, we investigated MP...     

催化臭氧氧化—好氧生化—膜分离组合工艺处理砷化镓生产废水的工程应用

为了解决砷化镓生产废水含有磷酸盐、氟化物、砷化物以及难沉降亚微米级悬浮物的处理难点,首先采用催化臭氧氧化—好氧生化深度预处理废水,再采用RO膜分离工艺进行处理。结果表明：催化臭氧氧化法使废水中亚微米级悬浮物脱稳,有利于悬浮物的混凝沉降,并优化了膜分离阶段的分离环境,可延长膜使用寿命,降低运行成本;经过膜分离后,出水砷质量浓度为0.01 mg/L,氟质量浓度为1.0 mg/L,COD、TP、TN和ρ（NH₃-N）为10,0.01,0.50,0.50 mg/L,均达到《地表水环境质量标准》（GB3838—2002）Ⅲ类水质标准。     

石油企业环境保护与实现可持续发展的途径

针对环境问题对石油工业的影响,提出了石油工业发展必须建立环境保护工作体系的创新思维。通过技术创新和采用先进的管理方式,使石油企业的环境保护水平适应可持续发展的要求,为实现21世纪石油工业新的腾飞奠定基础。     

基于动态聚类分析和盲数理论的综合营养状态指数评价模型

考虑到常用水质富营养化评价模型的单一、确定性缺点,尝试将动态聚类分析与盲数耦合理论引入水环境富营养化评价领域,建立了改进的综合营养状态指数评价模型,最后借助克里格插值法对评价结果的可信度进行空间可视化表征。利用改进模型对2009年洞庭湖区域的水环境空间的富营养化状况进行了评价,结果表明,东洞庭湖、扁山、鹿角富营养化程度相对严重,隶属于富营养化的可信度分别达到了0.5444、0.5318和0.5260。与确定性评价模型对比分析表明,所建改进模型更充分地考虑到被观察个体的差异,集成了更全面的样本信息,并可同时计算出了各采样点综合营养状态指数的区间数与其相对应的可信度水平,从而有效地提高了评价模型的可分辨性。     

污泥厌氧消化的人工神经网络模型

基于污泥固体停留时间(SRT)为20 d的污泥中温厌氧消化实验,建立一个3层BP神经网络,以前1～20 d的进泥挥发性悬浮固体(VSS)、当天消化罐pH值和碱度共22个参数为输入,预测污泥消化系统日产气量,结果表明,网络具有良好的学习能力、泛化能力和辨识能力,能够较为准确地预测出系统日产气量.此外,根据进泥VSS不同,利用网络预测能力,调节pH值和碱度到合适的值,系统日产气量有明显提高,进一步证明了网络具有良好的预测能力和实用性.     

具有可见光活性的氮掺杂TiO_2光催化剂的制备及光催化性能

采用浓氨水处理Ti(SO4)2溶液,然后经过滤、干燥、煅烧制备了一种氮掺杂TiO2光催化剂TiO2-XNX,其最佳煅烧温度为400℃。对该光催化剂的XRD谱图进行分析,结果表明,TiO2-XNX的晶型为锐钛矿相。紫外—可见吸收光谱表明,该光催化剂在可见光区具有明显的吸收。甲基橙溶液的降解实验结果表明,制备的TiO2-XNX光催化剂具有可见光(波长λ400nm)活性。     

Effect of arsenate on adsorption of Cd(II) by two variable charge soils

The effect of arsenate on Cd(II) adsorption in two variable charge soils and the desorption of Cd(II) pre-adsorbed in the presence of arsenate were studied. The batch type experiments showed, the presence of arsenate led to increase in Cd(II) adsorption and the desorption of pre-adsorbed Cd(II). Further it was observed that the extent of adsorption and desorption of Cd(II) was greatly influenced by the initial concentrations of arsenate and Cd(II), the solution pH, and the nature of the soils. In general the increase in arsenate concentration and pH favored the uptake of Cd(II). Moreover, the arsenate concentration influenced more in Hyper-Rhodic Ferralsol than Rhodic Ferralsol at least for the Cd(II) adsorption/desorption. This may be due to the content of Fe/Al oxides in these soils. The larger the content of Fe/Al oxides, the more the adsorption of arsenate by the soil, hence greater the uptake of Cd(II). It can be assumed that the enhanced Cd(II) adsorption was mainly due to the increase in net negative surface charge of the soil induced by the adsorption of arsenate, because the presence of arsenate led to the decrease in zeta potential of these soil suspensions. The increase of electrostatically adsorbed Cd(II) was responsible for the increase in the desorption of Cd(II) pre-adsorbed in the presence of arsenate.