Application of a new type of moving bio-film in aerobic sequencing batch reactor (aerobic-SBR)

A moving bio-film (MB), made from the inner tube of used tyres was applied in a conventional-aerobic-SBR for increasing the system efficiency and quality of bio-sludge due to good sedimentation (the density of 1.925+/-0.21 g/cm(3)), non-biodegradability and re-usability of the media without any regeneration. The total bio-sludge mass of the MB-aerobic-SBR was about 30% higher than that of the conventional-aerobic-SBR resulting in a reduction of the F/M value of the system and amount of suspended bio-sludge waste. The amount of suspended bio-sludge waste, SVI and SRT of the MB-aerobic-SBR under a low organic loading of 80+/-9.3g BOD(5)/m(3)-d were 1,485+/-146 mg/d, 51+/-3.7 ml/g and 10.1+/-5.1 days, respectively while they were 1,800+/-152 mg/d, 69+/-4.0 ml/g and 8.3+/-5.3 days, respectively in the conventional-aerobic-SBR. The BOD(5), TKN and TP removal efficiencies of the MB-aerobic-SBR were about 1-2, 2-3 and 10-12% higher, respectively, than that of the conventional-aerobic-SBR. Also, the BOD(5) and COD removal efficiencies of the MB-aerobic-SBR were higher than 95% even when the system was operated with synthetic wastewater containing 800 mg/l BOD(5) under a very low HRT of 1.5 days (organic loading of 528+/-50.8 g BOD(5)/m(3)-d). The effluent BOD(5), COD, total kjeldahl nitrogen, total phosphorus and suspended solids of the MB-aerobic-SBR under a high organic loading of 528+/-50.8 g BOD(5)/m(3)-d were 45+/-5.1, 37+/-3.6, 4.1+/-1.0, 1.5+/-0.80 and 41+/-2mg/l, respectively.     

管道烟气静压测量方法探讨

通过对三种常用管道烟气静压测定法进行理论和试验分析,推荐一种实用的静压间接测定法,并对该法进行理论分析和试验验证。     

渗灌——设施园艺先进的节水灌溉技术

渗灌具有降低室内湿度、改善土壤环境、节约灌溉用水、减少肥料用量、省工省时、价格适中等优点,是目前设施园艺先进的节水灌溉技术。详细介绍了渗灌系统的结构,渗灌管的种类以及使用维护方法。     

Numerical study on the spontaneous ignition of pressurized hydrogen release through a tube into air

Spontaneous ignition of pressurized hydrogen release through a tube into air is investigated using a modified version of the KIVA-3V CFD code. A mixture-averaged multi-component approach is used for accurate calculation of molecular transport. Autoignition and combustion chemistry is accounted for using a 21 step kinetic scheme. Ultra fine meshes are employed along with the Arbitrary Lagrangia–Eulerian (ALE) method to reduce false numerical diffusion. The study has demonstrated a possible mechanism for spontaneous ignition through molecular diffusion.

In the simulated scenario, the tube provided additional time to achieve a combustible mixture at the hydrogen–air contact surface. When the tube was sufficiently long under certain release pressure, autoignition would initiate inside the tube at the contact surface due to mass and energy exchange between low temperature hydrogen and shock-heated air through molecular diffusion. Following further development of the hydrogen jet downstream, the contact surface became distorted. Turbulence plays an important role for hydrogen/air mixing in the immediate vicinity of this distorted contact surface and led the initial laminar flame to transit into a stable turbulent flame.     

Occupational electrical injuries in the United States, 1992-1998, and recommendations for safety research

PROBLEM: CFOI and SOII data show that 2,287 U.S. workers died and 32,807 workers sustained days away from work due to electrical shock or electrical burn injuries between 1992 and 1998. METHOD: The narrative, work activity, job title, source of injury, location, and industry for each fatal electrical accident were examined. A primary causal factor was identified for each fatality. RESULTS: Electrical fatalities were categorized into five major groups. Overall, 44% of electrical fatalities occurred in the construction industry. Contact with overhead power lines caused 41% of all electrical fatalities. DISCUSSION: Electrical shock caused 99% of fatal and 62% of nonfatal electrical accidents. Comprising about 7% of the U.S. workforce, construction workers sustain 44% of electrical fatalities. Power line contact by mobile equipment occurs in many industries and should be the subject of focused research. Other problem areas are identified and opportunities for research are proposed. IMPACT ON INDUSTRY: Improvements in electrical safety in one industry often have application in other industries.     

炭素焙烧炉沥青烟静电除尘技术

针对炭素焙烧炉含尘低浓度高温沥青烟，优化设计方案，采用干式、湿式预处理和静电净化两级处理，先除去大粒径烟尘，降低烟尘温度，降低电阻率，后静电净化沥青烟。系统具有自动控制，节电节能，除尘效率高等特点。     

一种新型油管吊卡的研制与应用

介绍了新型吊卡销的结构和原理与安全性,剖析了可更换小月牙式油管吊卡的经济效益和推广应用前景。     

Reduction–melting combined with a Na2CO3 flux recycling process for lead recovery from cathode ray tube funnel glass

With large quantity of flux (Na₂CO₃), lead can be recovered from the funnel glass of waste cathode-ray tubes via reduction–melting at 1000 °C. To reduce flux cost, a technique to recover added flux from the generated oxide phase is also important in order to recycle the flux recovered from the reduction–melting process. In this study, the phase separation of sodium and the crystallization of water-soluble sodium silicates were induced after the reduction–melting process to enhance the leachability of sodium in the oxide phase and to extract the sodium from the phase for the recovery of Na₂CO₃ as flux. A reductive atmosphere promoted the phase separation and crystallization, and the leachability of sodium from the oxide phase was enhanced. The optimum temperature and treatment time for increasing the leachability were 700 °C and 2 h, respectively. After treatment, more than 90% of the sodium in the oxide phase was extracted in water. NaHCO₃ can be recovered by carbonization of the solution containing sodium ions using carbon dioxide gas, decomposed to Na₂CO₃ at 50 °C and recycled for use in the reduction–melting process.     

600 MW机组省煤器灰中等距离气力输送系统改进措施

某电厂省煤器灰气力输送系统投运初期频繁出现堵管和输灰超时的问题。经过分析及调研后,改用双套管输送,优化输送步序,减少输送耗气量,不仅实现了输送系统平稳顺畅,而且避免了灰管过度磨损的现象。     

MBBR法应用于工业废水处理的研究

关于实心钢管混凝土的耐火性能已有大量的实验研究,而空心钢管混凝土的耐火实验目前还非常少见。针对这一不足,对空心钢管混凝土进行了耐火实验研究,其中考虑了不同的空心率,并对中空注水对构件耐火性能的影响也进行了实验研究。实验结果表明:在相同的荷栽比下,构件的耐火时间随空心率先增大后减小。当空心率较小时,中空注水对构件耐火时间的提高作用不明显;当空心率较大时,注水对耐火时间的提高才体现出来。