燃料乙醇企业循环经济的实例研究

以北方某燃料乙醇生产系统为例,从物质、能量和水的流动等方面定量地分析其实践循环经济的情况,并结合清洁生产指标体系做了对比分析。着重分析了此生产系统的废物链的组成及其作用,并探讨了进一步发展循环经济的措施。结果表明:燃料乙醇生产系统的原料为可再生资源,主要产品燃料乙醇具有环境友好性;废物链的存在提高了物质利用率、能量利用率和能量保有率,减少了废物的排放,提高了经济效益;通过对废物链的补充还可进一步体现循环经济特性。     

大型基坑工程信息化施工中的监测技术与实例分析

信息化施工是岩土工程发展的方向,发展基坑工程的信息化施工技术可以更好地为设计和施工服务。介绍基坑工程信息化施工中运用监测技术的重要性,列出了监测项目和方法,并结合某大型建筑的基坑工程实例简述信息化施工在深基坑工程建设中的应用。以实例分析阐述监测工作在信息化施工中的作用和地位,以及现行的监测技术。信息化施工中监测技术与施工质量和安全息息相关。     

钻探施工中的安全管理

本文结合钻探施工的实际情况,从五个方面论述了安全管理的操作,为钻探施工安全管理提供了有益的借鉴。     

黄河小浪底水利枢纽工程洞群施工测量

小浪底水利枢纽工程洞群部分包括导流洞、明流洞、排沙洞、发电洞、孔板洞、灌溉洞等各种隧洞108条。洞群施工控制网是在小浪底GPS首级控制网的基础上布设的，为便于施工和快速放样，首先建立以每条遂洞轴线为北方向的坐标系，并将隧洞原设计采用的国家大地坐标转换为每条隧洞的施工坐标。在开挖测量中，用全站仪配合CASIO fx-4800机算器，计算超欠挖及隧洞拱顶变形值。为保证隧洞施工与设计一致，在断面测量中还使用了瑞士徕卡公司新生产的AMT3000激光无棱镜断面仪，大幅度提高了工作效率：     

水平对接卤井施工技术

陕北两水平对接采卤井,对接靶点垂深2541.42m,水平距离365.89m,设计造斜点垂深2328m,造斜率25～30°/100m。垂直井深达2311.5m时,井斜1.08°,偏距5.69m,远离靶区,据此根据造斜钻具性能,造斜点改为2311.5m。     

中国城市化进程中基础设施建设和管理的问题与对策探讨

城市基础设施是城市赖以生存和发展的基础，是既为物质生产又为人民生活提供一般条件的公共设施。城市基础设施可以推动城市化进程，同时城市化也可以影响城市基础设施的发展。在阐明城市化进程和城市基础设施关系的基础上，分析了中国城市化进程中城市基础设施建设和管理的现状，并探讨了其存在的诸多问题，认为建立多元化的投融资格局、改革政府投资的决策和管理方式、积极推进城市基础设施行业的国有企业产权转换和机制转换将是中国城市化进程中优化城市基础设施建设和管理的必要举措。     

论建设生态城市的立足点

从生态城市的内涵、结构组成、功能及特点等生态城市有关的基本理论分析入手,探讨建设生态城市的理论依据.在分析中国建设生态城市所面临的问题和现状的基础上提出中国建设生态城市的基本立足点,可以概括为：（1）以城乡共同发展为准则;（2）以加大科研投入,提高教育水平,提高人口素质为先导;（3）以生态修复为基础;（4）以发展循环的经济为核心;（5）以加强环境立法,提高环境管理效率为手段.     

东辽河铁路大桥桩基础施工地质问题的处理

东辽河铁路大桥地基的第四系存在多原因形成的人为物质,构成桥桩基础施工的障碍,使桩孔钻探施工难以进行。经采用多种方法对不同问题进行处理,达到了施工目的。     

Hydrogeology of deep-well disposal of liquid wastes in southwestern Florida, USA

 Deep-well injection has been used to dispose of municipal liquid wastes in southwestern Florida since 1988. The liquid wastes are injected into an extremely high-transmissivity zone of fractured dolomite in the Early Eocene Oldsmar Formation of the Floridan aquifer system; this zone is commonly referred to as the Boulder Zone. Data collected during the drilling and operational testing of southwestern Florida injection wells provide insights into the nature of the injection zone and overlying confining beds. The location of high-transmissivity zones that are capable of accepting large quantities of waste water is vertically and horizontally variable and cannot be predicted with certainty. A 40.9-m thick high-permeability interval in one injection well, for example, was absent in a well drilled only 85.4 m away. Some upward migration of low-density injected fluids has occurred, but at no site were the injected liquids detected in deep monitor wells, such as occurred at injection-well sites along the coasts of southeastern, west-central, and east-central Florida. The primary confinement of the injected liquids (i.e., deepest effective confining beds) consists of unfractured beds of low-permeability dolomite within the Oldsmar Formation, whose locations are also laterally and vertically variable. The origin and controls of the distribution of fractures in the Oldsmar Formation are poorly understood. Received, December 1997 Revised, June 1998, August 1998 Accepted, August 1998     

Geochemical demobilization of metallic pollutants in solid waste—implications for arsenic in waterworks sludges

During stabilization or demobilization of contaminants in solid waste materials, different approaches can be taken, which also can be combined: (1) sufficient long-term buffer capacity can be provided, according to the environmental conditions; (2) permeability for dissolved contaminants can be reduced by secondary mineral precipitations or by soft gels injected into the pore space of the waste body; and (3) new formations of ‘reservoir minerals' can incorporate potential pollutants in their internal structure. Emphasizing the geochemical engineering approach, two examples are presented from the field of water management, both focussing on the demobilization of arsenic species. The first example (after Driehaus, W., 1994. Arsenentfernung mit Mangandioxid und Eisenhydroxid in der Trinkwasseraufbereitung. Vol. 133, Ser. 15, VDI-Reports, Düsseldorf, 117 pp.) relates to the problems during purification of arsenic-rich raw water, suggesting the potential application of iron and manganese oxide minerals as oxidizing agents and mineral lattice structures for the elimination of arsenic. In the second example, contaminated sludges from water treatment plants were investigated for their leaching characteristics and long-term stability. A pH-stat test procedure was used to assess the leaching characteristics of metals at typical pH values. Due to the presence of iron and manganese oxides pentavalent arsenic is protected against conversion into the mobile trivalent form at neutral to low pH. Experimental data suggest that co-disposal with reducing organic matter and alkaline stabilization material or wastes could negatively influence the binding properties and, therefore, should be avoided.