兰州市排污权交易制度研究

作为市场手段和环境治理结合所产生排污权交易制度,被越来越多的国家和地区证明其对缓解环境问题有着独特的、重要的作用。随着我国市场经济的深入发展、市场条件的日趋成熟,排污权交易也在国内许多省市进行深入试点,并产生了一定的效益。本文从排污权交易理论出发,结合兰州的污染现状,论证兰州市实行排污权交易的必要性和可行性。最后,在借鉴国内外排污权交易成功经验的基础上,对兰州市排污权交易制度的构建提出建议。     

渣油加氢脱硫装置蒸气云爆炸后果研究

简要分析了渣油加氢脱硫装置火灾爆炸危险性,模拟了VRDS装置氢气泄漏后引发蒸气云爆炸的事故后果。通过分析计算蒸气云爆炸后对人员以及装置设备造成的伤害／破坏范围,指导设计人员以及操作人员制定必要的安全防范措施,将蒸气云爆炸的后果最小化。     

地震发生后环境监测工作的思考

分析了地震发生后,可能发生的火灾、有毒有害物泄漏、水源污染等多种次生灾害,及目前现有的震后环境监测手段,提出针对可能的污染状况,应采取的环境监测措施及方法。     

石化CO2解析气应用于碳酸钠制造过程燃爆性分析

对炉气、解析气、上段气、碳化塔顶气体和尾气进行了燃爆性分析及测试,测定了上段气、碳化塔顶气和尾气的爆炸极限并采用三元组分图进行分析。结果显示,压缩前的上段气、碳化塔顶气和尾气随氧气含量的升高不可燃,尾气排空不存在燃爆危险。压缩后的上段气组成处于可燃范围之外。针对碳化塔顶气中氧气浓度已经超过限氧浓度值,提出了必须严格控制碳化塔顶气中的可燃气体浓度的建议。     

氨氧化反应器火灾爆炸危险因素分析及控制

利用故障树方法对羟胺肟化装置氨氧化反应器的火灾爆炸危险因素进行逻辑定性分析,并提出控制、预防措施。     

An overpressure-time history model of methane-air explosion in tunnel-shape space

This study investigated methane-air explosion in tunnel-shape space and developed an overpressure-time history model based on numerical results. The findings revealed that for the progressively vented gas explosion with movable steel obstacles in a 20 m long tunnel, the inner peak overpressure increased as the activation pressure of the tunnel top cover got higher but remained below 6 bar. However, as the activation pressure increased to 8 bar or higher, the peak inner overpressure remained unchanged. As the segment cover panel became wider, the peak pressure was almost unchanged, but the pressure duration and impulse declined significantly. The peak pressure and impulse increased as the tunnel length vary from 10 to 30 m. With fixed tunnel length, higher blast pressure but lower impulse was observed as the inner obstacles were closer or the activation pressure of obstacles was higher. It is also found that a local enlarged space in the tunnel enhanced the peak pressure significantly. An overpressure time history model for the tunnel with fixed top cover and enlarged end zone was established. The model considered activation pressure of vent cover, area and length of vent opening, methane concentration, number and blockage ratio of fixed obstacles was developed to calculate the overpressure and corresponding time at characteristic points of the pressure-history curve. The cubic Hermite interpolation algorithm and a specially tuned formula consisting of the power and exponential function were used to interpolate pressure values between characteristic points. The proposed model can predict both the peak pressure and the overpressure time history with acceptable accuracy.     

基于自然灾害的北京幅综合生态风险评价

经过20多年的发展,风险源评价从单一风险源扩展到多风险源,风险受体从单一受体发展到多受体,评价尺度也从种群、生态系统扩展到区域和景观水平。但总体说来,对多风险源、多过程的多个生态系统层次的风险评价尚不成熟。运用数字高程模型、干燥度分布图、植被指数、人口密度以及8种自然灾害风险源频率分布图、土地利用图、植被类型图、陆地生态系统生态资产分布图等数据,基于ArcGIS 9.2平台,综合考虑生态的脆弱性,风险源的发生频率,受体的暴露水平、危害程度等,对多风险源、多个生态系统综合的北京幅生态风险进行评价。旨在对区域综合生态风险评价方法进行探讨。评价结果显示：（1）高风险区主要为本区环渤海湾沿岸,包括天津市,河北唐山、沧州,山东滨州、东营、潍坊等沿海地带;以及本图幅西部、北部的太行山地,包括河北省、北京市及图幅西部的山西、河南部分地区;（2）较低生态风险区所占比例较高,达42.55%,可见降低生态风险有很大的潜力;（3）高强度的人类开发,尤其是在滨海地区围海造陆,将会导致沿海地区生态风险更高。     

Secondary aerosol formation in winter haze over the Beijing-Tianjin-Hebei Region,China

• Characteristics and interannual variation of aerosol pollution are illustrated. • Mechanisms of secondary aerosol formation in winter haze of North China are reviewed. • Directions in future studies of secondary aerosol formation are provided. Severe haze pollution occurs frequently in the winter over the Beijing-Tianjin-Hebei (BTH) region (China), exerting profound impacts on air quality, visibility, and human health. The Chinese Government has taken strict mitigation actions since 2013 and has achieved a significant reduction in the annual mean PM_2.5 concentration over this region. However, the level of secondary aerosols during heavy haze episodes showed little decrease during this period. During heavy haze episodes, the concentrations of secondary aerosol components, including sulfate, nitrate and secondary organics, in aerosol particles increase sharply, acting as the main contributors to aerosol pollution. To achieve effective control of particle pollution in the BTH region, the precise and complete secondary aerosol formation mechanisms have been investigated, and advances have been made about the mechanisms of gas phase reaction, nucleation and heterogeneous reactions in forming secondary aerosols. This paper reviews the research progress in aerosol chemistry during haze pollution episodes in the BTH region, lays out the challenges in haze formation studies, and provides implications and directions for future research.     

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing wastewater treatment

•PSBF performed better than PAC and PAM in CODCr removals. •PSBF was more insensitive to changing pH than PAC and PAM. •PAC could remove humic acid-like pollutants and dye particles. •PSBF was efficient in removing tryptophan-like pollutants from PPDW. •A secondary coagulation-flocculation process (PAC→PSBF) is proposed here. In our previous studies, several papermaking sludge-based flocculants (PSBFs) were synthesized from wood pulp papermaking sludge. The structure-activity relationships of the PSBFs have been investigated in simulated dye wastewater treatment, but their efficiencies in practical printing and dyeing wastewater (PPDW) treatment are unknown. Herein, an PSBF was prepared, and its performance is discussed in comparison to polyaluminium chloride (PAC) and polyacrylamide (PAM) in PPDW treatment. The PSBF was used in three ways: as an independent flocculant, as a PAC aid, or used to treat the effluent of the PAC system. The results indicated that adding PSBF alone produced similar color and chemical oxygen demand (COD_Cr) removals as the PAC system alone, but PSBF performed better than PAC when the pH of PPDW was higher than 7.0. Adding PSBF as a PAC aid improved the color, COD_Cr and turbidity removals, but the elimination efficiencies were slightly lower than those of the PAC+ PAM system. However, when PSBF was used as a flocculant to treat the effluent of the PAC system (PAC→PSBF), the effluent qualities were enhanced. Compared with the PAC system, the color and COD_Cr removals of PAC→PSBF system increased by 16.21% and 13.26%, respectively. The excitation and emission matrix fluorescence results indicated that PSBF removed tryptophan-like pollutants more efficiently than PAC. Considering the pH requirements of the subsequent bioreactor treatment in practice, the PAC→PSBF system were also investigated at the PPDW pH level of 7.0. Its maximum removal efficiencies of color, COD_Cr and turbidity were 90.17%, 32.60% and 82.50%, respectively.     

爆炸应力波在层状节理岩体中的传播规律试验研究

为了研究爆炸应力波在岩体中的传播规律,基于相似理论,开展了爆炸应力波在层状节理岩体中衰减的实验研究。研究表明,节理阻碍 应力波的传播且存在各向异性;对于垂直或小角度入射节理的应力波,在垂直方向和纵向的衰减很明显并且幅度较大,在横向衰减不明显;对 于斜入射节理的应力波,横向和垂直方向没有明显的衰减,纵向的衰减很明显并且幅度较大;应力波的合成峰值速度与炮孔密集度之间的关系 密切,当炮孔间距超过一定距离时,实际测得的速度时程为最近药包爆破产生的应力波,并非总药量产生的应力波的叠加。