An efficient and clean oxidative bromination reaction of phenol catalyzed by ammonium salt of heteropoly acids supported on silica

An efficient and eco-friendly oxidative bromination reaction of phenol has been achieved by treatment with KBr–H₂O₂ in the presence of a catalytic amount ammonium salt of molybdophosphoric acid or phosphotungstic acid that supported on silica, which were synthesized by sol–gel method. The physicochemical characterization indicated that supported catalysts still retained its Keggin type and the particles were well dispersed onto the surface of silica support. The evaluated results of liquid phase bromination of phenol showed that these catalysts exhibited high catalytic oxybromination activity and high para substituted selectivity, and good stability was also observed after recycling three times. Meanwhile, no highly toxic and corrosive materials were used and formed in the reaction process, which makes this process environmentally benign. The influences of the reaction time, catalyst amount and solvent on oxidative bromination reaction were also investigated.     

震动强度对反倾层状岩质边坡动力响应规律的影响

通过振动台模型试验探讨震动强度对反倾层状岩质边坡动力响应规律的影响,着重分析边坡加速度响应峰值、加速度放大系数随震动强度增加的变化规律。结果表明:①随着震动强度增加,模型边坡各测点的加速度响应峰值不断增大,地震波频率和测点位置影响加速度响应峰值的增加方式;②震动强度对模型边坡各测点加速度放大系数的影响因地震波频率、测点位置的不同而有不同的表现。同一频率地震波作用下,相同高程的测点加速度放大系数随震动强度增加的变化规律相同;③0.20g是边坡变形破坏的临界加速度值;④震动强度的变化并不改变加速度响应峰值、加速度放大系数在边坡中的分布。该研究结果对高地震区的地质灾害防治具有指导和借鉴-意义。     

能源动力工程的总资源评价方法

在评价能源动力工程项目时应该采用综合的评价方法，考虑技术、经济和环境等因素。本文在此陈述了一种基于总资源系统的综合评价方法，将生产中消耗的(包括污染掉的)空气、水和燃料等都折算成资源，并从社会平均边际削减成本的角度计算了利用资源对社会造成的外部成本。本文指出，计算资源的价值时必须包括其外部成本，并计人最终的总成本。文中陈述了这一综合评价方法的原理，并以某燃天然气的燃气轮机联合循环热电联产系统为例子，与燃煤分产系统进行了粗略的比较计算。     

悬浮液进样火焰原子吸收光谱法测定环境样品中钙、镁

将环境样品制成悬浮液，用空气／乙炔火焰原子吸收光谱法测定钙、镁、以三氯化镧、丙三醇和高氯酸为混合抗干扰剂，有效消除了环境样品中铅、磷、硫、硅等共存元素的干扰，其中丙三醇不仅是抗干扰剂，而且还起着稳定剂的作用，进一步简化了测定步骤，有效提高了分析速度。本文通过水溶液标准曲线校正，使测定更加方便。对测定结果与湿法消化法比较，具有较好的相关性。本法简便、快速、测定分析结果准确可靠。     

浅谈影响燃煤锅炉除尘效率因素及对策

根据抚顺市燃煤锅炉除尘器现状，选择了三种容量、三种运行负荷燃煤锅炉除尘器进行测试。测试结果说明：锅炉运行负荷、供风方式是影响燃煤锅炉除尘器使用效率的主要因素。最后，提出了提高燃提锅炉除尘器使用效率对策。     

光伏充电站环境效益综合评价

运用模糊综合评价法对光伏充电站的环境效益进行综合评价。通过构造区间互补判断矩阵等步骤计算模糊评价矩阵,并进行归一化计算,最后对照评语集得到评价结果。实证分析北京市铁路货场改造成为绿色物流配送中心及电动汽车充电站,用层次分析法确定4个方面(生态环境效益、环境质量效益、能源环境效益、社会环境效益)12项指标(增加土地利用率,促进资源开发利用,推动植被保护;减少CO2排放,减少NOx排放,减少PM排放;促进新能源替代,降低车辆能耗成本,促进能源结构调整;改善居民生活水平,增加环保公众意识,减少征地拆迁矛盾),综合评价结果显示环境效益很好,评价结果为光伏充电站行业的健康发展,环境保护防治等方面提供一定依据。     

A gradient of mercury concentrations in Scottish single malt whiskies

Mercury (Hg) concentrations were measured in 26 Scottish single malt whiskies, and all found to be very low (<10 ng L⁻¹), posing no threat to human health through reasonable levels of consumption. However, a significant south-to-north declining gradient in Hg concentrations was observed reflecting that reported for atmospheric deposition. We speculate that this gradient could be due to a combination of contemporary deposition and the legacy of industrial mercury emissions and deposition over the last 200 years affecting concentrations in local waters used in whisky production. As UK atmospheric emissions of mercury have declined by 90 % since the 1970s, we suggest that whisky being produced today should have even lower Hg concentrations when consumed in 10- to 15-years time. This reduction may be compromised by the remobilisation of contaminants stored in catchment soils being transferred to source waters, but is very unlikely to raise the negligible health risk due to Hg from Scottish single malt whisky consumption.

     

投菌法应用于A~2O工艺处理焦化废水的中试研究

为寻找一种不经稀释直接处理焦化废水的途径,本中试将投菌法与A2O工艺结合,对石家庄焦化厂焦化废水进行处理研究。通过对焦化废水进行GC-MS分析,选择出焦化废水中含量较高的难降解物质,然后进行单一碳源优势菌培养,获得优势菌群。优势菌群投加于工艺的好氧段。整个中试过程分为污泥的培养及驯化阶段,稳定运行阶段及冲击恢复阶段。经过半年的实验,整套工艺具有较好的稳定性及抗冲击能力。对未经稀释的焦化废水的CODCr平均去除率为94.2%,氨氮平均去除率为85.6%。     

Trace element pollution records in some UK lake sediments, their history, influence factors and regional differences

Sediment cores were taken from six sites across the UK. Apart from Banbury Reservoir in London, all the other sites are relatively remote lakes. Trace elements Pb, Zn, Cu, Cd, Cr, Ni, Sn, As and V, major elements such as Fe, Mn, Ti and Al were analysed, and organic content measured as loss-on-ignition was determined in all of these cores. The result shows that these relatively remote sites have experienced enhanced atmospheric deposition of anthropogenically derived trace elements for over 100 years, and the contamination might start before industrialisation. Trace metal contamination remains the highest level at Banbury Reservoir showing "pollution source" influence. Despite the considerable reduction in atmospheric deposition in recent years, although some of the element concentrations in the surface sediments have declined, they are still much higher than their natural background values. In these sites, trace element pollution records have been influenced by many different factors. Redox condition could affect As distribution in the sediments. Sediment matrix could also affect trace element pollution signal. Apart from direct atmospheric deposition, the distributions of trace elements in the sediments have been affected by forestry activities and catchment erosion, and more contaminated soil in-wash could increase sediment pollution whilst less contaminated soil could dilute sediment pollution. In some sites, data suggest that catchment in-wash is an important source of elements for the lakes.