Characteristics of greenhouse gas emission in three full-scale wastewater treatment processes

Three full-scale wastewater treatment processes, Orbal oxidation ditch, anoxic/anaerobic/aerobic （reversed A^2O） and anaerobic/anoxic/aerobic （A^2O）, were selected to investigate the emission characteristics of greenhouse gases （GHG）, including carbon dioxide （CO2）, methane （CH4） and nitrous oxide （N2O）. Results showed that although the processes were different, the units presenting high GHG emission fluxes were remarkably similar, namely the highest CO2 and N2O emission fluxes occurred in the aerobic areas, and the highest CH4 emission fluxes occurred in the grit tanks. The GHG emission amount of each unit can be calculated from its area and GHG emission flux. The calculation results revealed that the maximum emission amounts of CO2, CH4 and N2O in the three wastewater treatment processes appeared in the aerobic areas in all cases. Theoretically, CH4 should be produced in anaerobic conditions, rather than aerobic conditions. However, results in this study showed that the CH4 emission fluxes in the forepart of the aerobic area were distinctly higher than in the anaerobic area. The situation for N2O was similar to that of CH4： the N2O emission flux in the aerobic area was also higher than that in the anoxic area. Through analysis of the GHG mass balance, it was found that the flow of dissolved GHG in the wastewater treatment processes and aerators may be the main reason for this phenomenon. Based on the monitoring and calculation results, GHG emission factors for the three wastewater treatment processes were determined. The A^2O process had the highest CO2 emission factor of 319.3 g CO2/kg CODremoved, and the highest CH4 and N2O emission factors of 3.3 g CH4/kg CODremoved and 3.6 g N2O/kg TNremoved were observed in the Orbal oxidation ditch process.     

基于移动监测的隧道内部PM_(2.5)与PM_(10)质量浓度分布研究

以上海市5条隧道为研究对象,采用车载移动监测的方式监测记录各条隧道沿程颗粒物(PM_(2.5)和PM_(10))的质量浓度,结合隧道自身特点,探究隧道内部颗粒物分布规律和成因。结果表明:隧道内颗粒物质量浓度分布主要与隧道自身的通风方式、结构特点和通过的车辆及其形成的活塞风有关。通过平行比较5条隧道的通风效果,发现翔殷路隧道通风效果较好,人民路隧道北线污染较为严重。     

一种封闭式选煤车间的设计

近年来,随着国家对煤炭行业控制环境污染的条件越来越严格,为了更有效的治理煤场环境污染,改善煤场周边地区环境质量,根据国内已建成的大型封闭厂房的设计经验,提出一种封闭式煤炭风选车间,车间采用轻型门式钢架结构设计,常规经济柱距6m,抗风柱柱距7．5m,室内净高10m。工程长度90m,跨度35m,屋盖系统采用钢桁架结构体系,单层压型彩色钢板封闭。封闭车间同时配套通风除尘系统,有效降低煤尘量。     

表流型和渗滤型植草沟净化城市地表径流试验研究

设计了表流型和渗滤型两类黑麦草植草沟,考察了不同水力负荷下(4、6、8 m~3/(m~2·d)),2类植草沟对城市地表径流的净化能力。研究结果表明:表流型植草沟对TSS、COD、TN、TDN、TPN、NH3-N、TP、TDP、TPP平均去除率分别为(77.44±4.4)%、(28.03±6.51)%、(27.07±9.88)%、(24.01±10.95)%、(52.47±10.15)%、(27.53±4.06)%、(39.25±4.97)%、(31.67±5.46)%、(71.96±5.57)%。渗滤型植草沟去除率则依次为(91±3.93)%、(43.72±12.71)%、(35.53±10.89)%、(31.59±11.26)%、(66.49±6.36)%、(47.91±8.30)%、(61.71±11.16)%、(56.45±12.84)%、(80.79±12.07)%。增设渗滤管后的渗滤型植草沟,整体去除效率高于表流型植草沟,提高了植草沟对径流的净化效果。较高水力负荷下,两类植草沟对污染物的净化均受到水力负荷的明显影响,其去除效率都随水力负荷的增大而减小。     

侧沟式一体化氧化沟处理污水技术

本文介绍了侧沟式一体化氧化为处理污水的工艺技术。该技术充分利用了氧化沟的优点，并用侧沟进行泥水分离和回流。工艺流程简单，易于操作，低投资高效益。是城市污水处理的新方法。     

局部通风机消音装置的研制

对局部通风机消音装置在降噪过程中远距离通风造成的阻力损失过大，从减小消音装置结构尺寸等方面做了探讨，并研制出较适合煤矿井下生产的局部通风机消音装置。