四川地区高含硫化氨气田钻完井风险因素分析

通过对川东北地区钻完井事故资料的统计,分析了影响高含硫化氢气田钻完井安全的主要风险因素。     

垃圾填埋场采用钠基膨润土防水毯防渗技术的探讨

目前内蒙古各城市生活垃圾的处置方式,大多采用卫生填埋法。防渗是卫生填埋处理技术的主要标志,它能防止垃圾在填埋过程中产生的渗滤液对水体污染。近几年钠基膨润土防水毯在卫生填埋场中得到快速发展,现已部分或全部取代粘土防渗层。本文主要从工程施工、质量、造价等分析膨润毯取代粘土防渗层的优势以及采用粘土防渗层对生态环境产生的不利影响。     

Variation characteristics of atmospheric methane and carbon dioxide in summertime at a coastal site in the South China Sea

● Diurnal patterns of CH₄ and CO₂ are clearly extracted using EEMD. ● CH₄ and CO₂ show mid-morning high and evening low patterns during sea breezes. ● Wind direction significantly modulates the diurnal variations in CH₄ and CO₂. Methane (CH₄) and carbon dioxide (CO₂) are the two most important greenhouse gases (GHGs). To examine the variation characteristics of CH₄ and CO₂ in the coastal South China Sea, atmospheric CH₄ and CO₂ measurements were performed in Bohe (BH), Guangdong, China, in summer 2021. By using an adaptive data analysis method, the diurnal patterns of CH₄ and CO₂ were clearly extracted and analysed in relation to the sea breeze (SB) and land breeze (LB), respectively. The average concentrations of CH₄ and CO₂ were 1876.91 ± 31.13 ppb and 407.99 ± 4.24 ppm during SB, and 1988.12 ± 109.92 ppb and 421.54 ± 14.89 ppm during LB, respectively. The values of CH₄ and CO₂ during SB basically coincided with the values and trends of marine background sites, showing that the BH station could serve as an ideal site for background GHG monitoring and dynamic analysis. The extracted diurnal variations in CH₄ and CO₂ showed sunrise high and sunset low patterns (with peaks at 5:00–7:00) during LB but mid-morning high and evening low patterns (with peaks at 9:00) during SB. The diurnal amplitude changes in both CH₄ and CO₂ during LB were almost two to three times those during SB. Wind direction significantly modulated the diurnal variations in CH₄ and CO₂. The results in this study provide a new way to examine the variations in GHGs on different timescales and can also help us gain a better understanding of GHG sources and distributions in the South China Sea.     

农用地土壤重金属生态安全阈值确定方法的研究进展

农用地土壤重金属生态安全阈值作为农用地土壤环境质量基准制定的重要依据,近年来随着多学科的共同发展,农用地土壤重金属生态安全阈值的确定方法变得越来越完善,但目前对其的研究综述却鲜见报道。因此,文章综述了农用地土壤重金属生态安全阈值的确定方法,详细阐述了点模型、概率模型以及经验模型中的代表方法在确定农用地土壤重金属生态安全阈值方面的概念、原理、发展及应用,并深入探讨了各方法的适用情况和优缺点,系统分析了各方法在确定农用地土壤重金属生态安全阈值时的不确定性及影响因素,最后在前人的研究基础上提出了今后的主要发展方向,以期为我国农用地土壤环境质量标准的完善与细化及农用地土壤其他污染物生态安全阈值的确定提供参考依据。     

提高静电除尘器粉尘驱进速度方法研究

由Deutsch公式可知,尘粒驱进速度的大小直接决定着电除尘器除尘效率的高低。从提高驱进速度的角度入手,通过分析影响电除尘器除尘效率的主要因素与驱进速度的关系,得出提高电除尘器除尘效率的方法,为设计合理、高效、节能的静电除尘器提供指导。     

热带季节雨林林窗区域土壤-植物-大气连续体热力效应初步分析

利用西双版纳雾凉季和干热季热带季节雨林林窗的小气候观测资料,探讨了昼间林窗地表温、气温及下层植物的叶温的时空分布和变化规律,分析了叶温与气温和地表温的相互关系指出在林窗区域,由于受雾和太阳高度的影响,各小气候要素最大值随时间、季节的不同,出现在林窗不同的方位,并且存在叶温高值区时空动态位移现象;另外,林窗区域土壤-植物-大气连续体界面间热量传递方向随时间、季节的不同而发生着改变,甚至在同一时段内,林窗不同区域会存在热量传递方向截然相反的现象,显示出林窗内可能存在热量循环的小环流.其结果对深入探讨林窗区域的热量传输,小气候的形成机制、生物多样性和更新等问题均具有重要意义.     

Salinity exchange between seawater/brackish water and domestic wastewater through electrodialysis for potable water

● Present a general concept called “salinity exchange”. ● Salts transferred from seawater to treated wastewater until completely switch. ● Process demonstrated using a laboratory-scale electrodialysis system. ● High-quality desalinated water obtained at ~1 mL/min consuming < 1 kWh/m ³ energy. Two-thirds of the world’s population has limited access to potable water. As we continue to use up our freshwater resources, new and improved techniques for potable water production are warranted. Here, we present a general concept called “salinity exchange” that transfers salts from seawater or brackish water to treated wastewater until their salinity values approximately switch, thus producing wastewater with an increased salinity for discharge and desalinated seawater as the potable water source. We have demonstrated this process using electrodialysis. Salinity exchange has been successfully achieved between influents of different salinities under various operating conditions. Laboratory-scale salinity exchange electrodialysis (SEE) systems can produce high-quality desalinated water at ~1 mL/min with an energy consumption less than 1 kWh/m³. SEE has also been operated using real water, and the challenges of its implementation at a larger scale are evaluated.     

场地土-群桩基础-结构体系动力响应研究——大型振动台系列试验方案设计

以饱和砂土液化后场地失效模式特征与场地失效时群桩基础地震反应破坏机理为研究目的,依托中国建筑科学研究院大型模拟地震振动台系统,开展可液化场地、非液化场地在水平地震动激励下桩-土-结构动力相互作用动力体系大型振动台系列试验。基于本次系列试验研究对象以及试验目的,阐述了系列试验中动力模型体系相似比设计的基本原则、地基的制备、模型结构制作、各个种类传感器的选择与布设、输入地震记录的选取与工况安排等内容,介绍了阵列式位移计、非接触式位移动态采集系统等新型传感测试设备,并对所采用的层状单向剪切模型土箱设计合理性与科学性进行了验证。由之后的试验结果可知,本次系列试验设计方案是合理、可靠的,层状剪切模型箱的"模型箱效应"很小。     

北京地区采暖期SO2熏烟型污染及评估

随着北京城市建设的发展，为了保护环境，北京市的新建生活区均采用集中供热系统。燃烧后的有害气体通过烟排向大气，经过高空稀释后的烟气可以降低污染负荷，但是在某此气象条件下仍然造成了地面局部污染，本文在北京市丰台区一个生活小区的供热系统污染源环境影响评价的基础上，讨论了熏烟污染的发生及危害。