煤矿突发事件应急救援的群决策方法

提出了基于直觉模糊集的煤矿突发事件应急救援TOPSIS群决策模型。其中决策者权重采用偏好值与群体平均偏好值的相似度计算,属性指标权重采用直觉模糊熵权法确定。通过直觉模糊加权集成运算将各决策矩阵进行合成得到综合决策矩阵,利用改进后的直觉模糊距离公式计算出全部备选救援方案到正负理想解的距离,根据TOPSIS运算结果可以确定最佳事故救援决策方案。最后通过黑龙江省鸡西某矿的实例分析,验证了该模型的有效性及合理性。     

Serious BTEX pollution in rural area of the North China Plain during winter season

Atmospheric BTEX compounds(benzene, toluene, ethylbenzene and xylenes) in a rural site of the North China Plain(NCP) were preliminarily investigated in winter, and the outdoor concentrations(25.8–236.0 μg/m3) were found to be much higher than those reported in urban regions. The pollution of BTEX inside a farmer's house was even more serious, with combined concentrations of 254.5–1552.9 μg/m3. Based on the ratio of benzene to toluene(1.17 ± 0.34) measured, the serious BTEX pollution in the rural site was mainly ascribed to domestic coal combustion for heating during the winter season. With the enhancement of farmers' incomes in recent years, coal consumption by farmers in the NCP is rapidly increasing to keep their houses warm, and hence the serious air pollution in rural areas of the NCP during winter, including BTEX, should be paid great attention.     

From waste hot-pot oil as carbon precursor to development of recyclable attapulgite/carbon composites for wastewater treatment

The utilization of waste products as valuable materials was a technical imperative for waste management. In this study, the cost-effective attapulgite/carbon(APT/C) composite was developed for wastewater treatment using waste hot-pot oil as a carbon precursor through a facile one-step calcination process. The APT/C composite prepared at 300°C exhibited the excellent adsorption capacity and rapid equilibrium rate over a broad p H range for the removal of various pollutants. More importantly, the removal ratios of the composites toward Methyl Violet and tetracycline still remained 77.6% and 60.2% of the initial adsorption capacity after ten adsorption–regeneration cycles via a facile thermal regeneration strategy, respectively.Beyond all doubt, this research provided a feasible and economical way for the sustainable utilization of waste hot-pot oil in wastewater treatment, achieving the concept of disposal waste with waste and recycling.     

上海沙田湖养殖区及周边水体中氟喹诺酮类抗性基因的分布特征及其与环境因子关系

集约化水产养殖区常被认为是水体抗生素和抗性基因的主要潜在来源,然而对其该类水体中抗生素和抗性基因污染情况的研究仍相对匮乏.本文以上海市沙田湖养殖区及周边水体为调查对象,利用宏基因组学高通量测序技术,于2020年9月对水体中的氟喹诺酮类抗生素(fluoroquinolones,FQs)和氟喹诺酮类抗性基因(fluoroquinolones antibiotic resistance genes,FQs-ARGs)的种类和丰度进行了调查,并利用多元统计分析方法研究了水体理化因子和FQs对FQs-ARGs的影响.结果表明,沙田湖养殖区及周边水体共检测出5类耐药机制、共46种FQs-ARGs,其中各水体共有基因为44种.抗性基因mfd和patA在养殖水体和周边水体中均为优势抗性基因,抗生素抗性基因变异或突变为优势耐药机制.养殖水体和周边河湖水体、不同养殖品种水体之间FQs-ARGs的平均丰度无显著差异(P＞0.05).偏冗余分析(pRDA)表明,除了诺氟沙星和环丙沙星2种抗生素外,水体电导率(Spc)、总磷(TP)、总氮(TN)、氨氮(NH4+-N)、溶解氧(DO)、pH和叶绿素a(Chl-a)等环境因子是影响水体中FQs-ARGs组成与分布的关键性因子,且非抗生素因子的总贡献率远高于抗生素.     

外秦淮河底泥污染及疏浚效果

外秦淮河是南京市一条重要的城市景观行洪河道,多年来受工业及生活污水影响,内源污染严重.为充分了解外秦淮河底泥污染特征,为疏浚提供决策依据,对河道上、中和下游典型断面底泥界面微环境以及营养物含量进行调查,采用有机指数法和污染指数法对底泥污染状况进行评估,同时根据污染物垂向分布特征模拟清淤对底泥内源释放削减的影响.结果表明,上中下游底泥界面以上DO均值分别为4.62、 3.25和3.41mg·L^-1,且分别在4.4、 3.5和5.5 mm处消耗殆尽,是典型的城市河道污染特征体现.调查河段表层底泥的ω(TN)、ω(TP)和ω(OM)均值分别为1 734mg·kg^-1、 1 337 mg·kg^-1和4.82%,底泥TN和OM的有机污染指数均值为0.48,处于尚清洁水平,TP的单项污染指数均值为3.18,处于重度污染水平.模拟30 cm清淤深度结果表明,底泥SRP和Fe²⁺的释放速率较清淤前分别削减42%～82%和88%～96%,而NH⁺₄-N的释放速率却较清淤前有...     

Sequential removal of heavy metals ions and organic pollutants using an algal-bacterial consortium

The residual algal-bacterial biomass from photosynthetically supported, organic pollutant biodegradation processes, in enclosed photobioreactors, was tested for its ability to accumulate Cu(II), Ni(II), Cd(II), and Zn(II). Salicylate was chosen as a model contaminant. The algal-bacterial biomass combined the high adsorption capacity of microalgae with the low cost of the residual biomass, which makes it an attractive biosorbent for environmental applications. Cu(II) was preferentially taken-up from the medium when the metals were present both separately and in combination. There was no observed competition for adsorption sites, which suggested that Cu(II), Ni(II), Cd(II), and Zn(II) bind to different sites and that active Ni(II), Cd(II) and Zn(II) binding groups were present at very low concentrations. Therefore, special focus was given to Cu(II) biosorption. Cu(II) biosorption by the algal-bacterial biomass was characterized by an initial fast cell surface adsorption followed by a slower metabolically driven uptake. pH, Cu(II), and algal-bacterial concentration significantly affected the biosorption capacity for Cu(II). Maximum Cu(II) adsorption capacities of 8.5+/-0.4 mg g-1 were achieved at an initial Cu(II) concentration of 20 mg l-1 and at pH 5 for the tested algal-bacterial biomass. These are consistent with values reported for other microbial sorbents under similar conditions. The desorption of Cu(II) from saturated biomass was feasible by elution with a 0.0125 M HCl solution. Simultaneous Cu(II) and salicylate removal in a continuous stirred tank photobioreactor was not feasible due to the high toxicity of Cu(II) towards the microbial culture. The introduction of an adsorption column, packed with the algal-bacterial biomass, prior to the photobioreactor reduced Cu(II) concentration, thereby allowing the subsequent salicylate biodegradation in the photobioreactor.     

北京市危险化学品安全生产技术支撑体系建设

1引言 近年来,在北京市委、市政府的领导下,各职能部门的协同努力下,北京市危险化学品安全生产工作取得了显著成绩,制定了一系列危险化学品安全生产管理规范,开展了危险化学品从业单位安全质量标准化活动,进一步提高了从业单位的安全生产管理水平,我市危险化学品安全生产状况总体趋向好转.