危险化学品事故应急救援预案编制过程问题讨论

通过对编制危险化学品事故应急救援预案过程中若干问题的思考,探讨如何按国家安全生产监督管理总局颁布的<危险化学品事故应急救援预案编制导则(单位版)>的要求,结合石化企业的实际情况,编制或修订详细完善的危险化学品事故应急救援预案.     

高效厌氧产甲烷颗粒污泥中微生物多样性及定量化研究

以小试高效厌氧反应器不同运行阶段的颗粒污泥为对象,利用变性梯度凝胶电泳(DGGE)、荧光原位杂交(FISH)和实时定量链式聚合酶反应(RTQ-PCR)等技术研究了其中微生物种群的多样性、特征微生物的空间分布和定量关系,结果表明:随着反应器有机负荷逐渐提高,颗粒污泥中古菌的群落结构的变化较细菌更为明显;细菌多分布在颗粒外层,而古菌则主要分布在颗粒内层;古菌含量略少于细菌,但有逐渐增多的趋势;产甲烷丝菌在古菌中的含量增加明显.     

Risk assessment for safety of soils and vegetables around a lead/zinc mine

Concentrations of heavy metals (Pb, Zn, Cd, Cu) were determined in soils and vegetables (chrysanthemum, spinach and four cultivars of Chinese cabbage from the area adjacent to a Pb/Zn mine in Shaoxing, Zhejiang province, China, and compared with the Chinese National Standards for Soil Environmental Quality. The accumulation of heavy metals in cabbage cv. Siyuegreen was investigated at different distances from the center of the mine. The vegetable plantation soils were polluted with Pb, Cd, Cu and Zn, especially by Pb and Cd. The levels of Pb and Cd were 20 and 30 times higher than the permitted standards, indicating that this Pb/Zn mining area is unsuitable for agricultural use. Chinese cabbage, chrysanthemum and spinach had different enrichment coefficients. The enrichment coefficient of Cd from soil to roots of chrysanthemum was >80% and from roots to leaves of cabbage cv. Shanghaigreen was >120%. These vegetables were polluted by heavy metals and could not be regarded as safe for human consumption. Environmental accumulation of heavy metals in the vegetable plantation soils was proportional to heavy metal accumulation in vegetables and both were inversely proportional to the distance from the lead/zinc mine.     

Kinetics on the decomposition of polychlorinated biphenyls with activated carbon-supported iron

The process of destroying polychlorinated biphenyls (PCBs) generates exhaust gases that contain low quantities of PCBs, which cannot be disposed of easily. Activated carbon (AC) can be used to adsorb residual PCBs after disposal of high-level PCBs. We examined the chemical reactivity of AC-supported iron as a catalyst to decompose PCB-153, and varied three decomposition parameters (temperature, time and iron concentration) under an atmosphere of either air or N(2). We measured the Brunauer-Emmett-Teller (BET) surface area and pore volume of AC to assess the adsorption capacity of AC before and after decomposition. At low temperatures the adsorption process was more important than the decomposition process. The decomposition process was completed within 30 and 60 min under air and N(2), respectively. The efficiency of PCB-153 decomposition at 350 degrees C for 120 min was approximately 100.0% and 97.1% under air and N(2), respectively. Analysis of inorganic chloride ions revealed that PCB-153 was effectively destroyed during decomposition. The differences between decomposition under air and N(2) reflected differences in BET surface and pore volume.     

Methods for the preparation of a biodesulfurization biocatalyst using Rhodococcus sp

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.     

A robust approach for iterative contaminant source location and release history recovery

Contamination source identification is a crucial step in environmental remediation. The exact contaminant source locations and release histories are often unknown due to lack of records and therefore must be identified through inversion. Coupled source location and release history identification is a complex nonlinear optimization problem. Existing strategies for contaminant source identification have important practical limitations. In many studies, analytical solutions for point sources are used; the problem is often formulated and solved via nonlinear optimization; and model uncertainty is seldom considered. In practice, model uncertainty can be significant because of the uncertainty in model structure and parameters, and the error in numerical solutions. An inaccurate model can lead to erroneous inversion of contaminant sources. In this work, a constrained robust least squares (CRLS) estimator is combined with a branch-and-bound global optimization solver for iteratively identifying source release histories and source locations. CRLS is used for source release history recovery and the global optimization solver is used for location search. CRLS is a robust estimator that was developed to incorporate directly a modeler's prior knowledge of model uncertainty and measurement error. The robustness of CRLS is essential for systems that are ill-conditioned. Because of this decoupling, the total solution time can be reduced significantly. Our numerical experiments show that the combination of CRLS with the global optimization solver achieved better performance than the combination of a non-robust estimator, i.e., the nonnegative least squares (NNLS) method, with the same solver.     

Distribution and dissipation pathways of nonylphenol polyethoxylates in the Yellow River: Site investigation and lab-scale studies

Spatial distribution of nonylphenol polyethoxylates (NPEOs) and nonylphenol (NP) was investigated in a field study in Lanzhou Reach of the Yellow River. NPEOs and their metabolites were found in the river, with the maximum dissolved concentrations of 6.38 nmol/L for NPEOs, 0.19 nmol/L for nonylphenol ethoxy acetic acids (NPECs) and 0.79 nmol/L for NP, respectively. The maximum concentrations in the sediment and suspended particle samples were 1.50 and 5.09 nmol/g for NPEOs and NP, respectively. The effects of particles, light and microorganism on the dissipation of NPEOs in the river water were investigated based on lab-scale experiments. When natural particles were removed, 72% and 22% degradation of NPEOs were achieved at 120 h in non-sterile and sterile conditions with light, respectively. Different concentrations of NPECs were also observed in these experiments. When suspended particle matters (SPMs) were present, about 38-50% of NPEOs were sorbed to the particulate phase in only 1 h. As a result, the degradation of NPEOs and production of NPECs were inhibited. However, the combined sorption and degradation in the presence of SPMs resulted in lower dissolved NPEO concentrations than those in the absence of SPMs. Biodegradation was the most important pathway for NPEOs degradation in the river water, while NPECs seemed to be produced through both biological and abiological pathways.     

油层注水过程中水质不合要求的危害及保护措施

分析了油田在二次采油注水过程中,对水质的要求,讨论了水质不合格带来的危害并提出了保护措施.     

特警战训服面料开发技术研究

本文介绍了以芳纶纤维为主要材料的我国新一代特警战训服面料的技术研发及达到的主要性能指标。通过试验研究,开发了具有高强防撕裂、永久阻燃、耐高温、防静电、防油拒水、防酸碱等具有集成防护功能的特警战训服系列面料。     

雨雪冰冻灾害后粤北森林各林型凋落物动态

为了考察中国亚热带不同森林类型对雨雪冰冻灾害的响应模式,以粤北天井山3种代表性的林型—针叶林、阔叶林和混交林为对象,于不同森林类型中比较受损森林与未受损森林在凋落物年产量、成分及月际动态方面的差异,从而在凋落物水平上反映不同森林类型在雨雪冰冻灾害后的早期恢复力。研究结果表明,灾后针叶林、阔叶林和混交林的年凋落量分别为0.52、3.21、1.37 t.hm-2,比未受损的同种森林类型年凋落量显著减少,减少程度分别为87.89%、53.46%、76.78%。由此可以看出阔叶林的植被恢复情况最好,说明在凋落物水平上,其灾后恢复的早期阶段恢复力最强。在凋落物成分方面,灾后各森林类型叶凋落物所占比例显著增加,枝凋落物所占比例则显著减少。受损针叶林和阔叶林的凋落物月动态与未受损森林基本一致,但其波动幅度较小;在混交林中,受损和未受损森林其凋落量的季节动态模式则表现出不一致性且为不规则型。根据研究结果,建议在亚热带地区优先考虑种植阔叶林以促进受损森林在类似雨雪冰冻灾害的极端天气后的恢复。