Effect of liming on the distribution of heavy metals in untreated industrial sewage sludge produced in Pakistan for the cultivation of <Emphasis Type="Italic">Sorghum bicolor</Emphasis> (L.)

The recycling of sewage sludge on agriculture land represents an alternative, advantageous, disposal of this waste material. The aim of the present study was to evaluate the feasibility of using industrial sewage sludge, produced in Pakistan, as a fertiliser. Agricultural soil amended with 25% (w/w) sewage sludge with or without lime treatment was used for growing a variety of sorghum (PARC-SS-1). The mobility of the heavy metals (HMs) (Cd, Cu, Cr, Ni, Pb and Zn) and metalloid (As) in the untreated industrial waste water sewage sludge (UIWS) samples were assessed by applying a modified BCR (Community Bureau of Reference) sequential extraction procedure. The single extraction procedure comprised of the application of mild extractant (CaCl₂) and water for the estimation of the proportion of easily soluble metal fractions. The precision and accuracy of BCR was evaluated by using a certified reference material of soil amended with sewage sludge BCR 483. The plant available metal contents, as extracted by the deionised water and 0.01 M CaCl₂ solution and exchangeable fraction of BCR sequential, decreased with lime application in the range of 10–44% for As, Cr, Ni, Pb and Zn, except in the cases of Cd and Cu, where their mobility was increased by 10% and 24%, respectively. Sludge amendment enhanced the dry weight yield of sorghum and the increase was more obvious after liming up to 25%. The uptake of HMs were lower in test samples (3.2–21.8%), except for Cu and Cd, which was higher (4%), while they were below the permissible limit of these metals. The present experiment demonstrates that liming was important in factors facilitating the growth of sorghum in sludge-amended soil.     

中梁山煤矿北矿瓦斯泵房噪声治理

本文对分布面广而复杂的瓦斯泵房噪声源进行了测试和深入的分析,采用综合治理的方法使居民区噪声达到了国家城市环境噪声标准的要求,瓦斯泵房内降噪显著,取得了理想的治理效果。     

原子荧光光谱法测定蔬菜样品中铅

铅作为一种对人体有害元素,在蔬菜样品中必须被检测。应用原子荧光光度计检测铅的含量,具有取样量少、灵敏度高、检出限低等优点,适合于环境样品的分析检测。     

AFM probe based nano mechanical scribing of soda-lime glass

In recent years, demands for miniature components have increased due to their reduced size, weight and energy consumption. In particular, brittle materials such as glass can provide high stiffness, hardness, corrosion resistance and high-temperature strength for various biomedical and high-temperature applications. In this study, cutting properties and the effects of machining parameters on the ductile cutting of soda-lime glass are investigated through the nano-scale scratching process. In order to understand the fundamentals of the material removal mechanism at the atomic scale, such as machined surface quality, cutting forces and the apparent friction, theoretical investigation along with experimental study are needed. Scribing tests have been performed using a single crystal diamond atomic force microscope (AFM) probe as the scratching tool, in order to find the cutting mechanism of soda-lime glass in the nano-scale. The extended lateral force calibration method is proposed to acquire accurate lateral forces. The experimental thrust and cutting forces are obtained and apparent friction coefficients are deduced. The effects of feed rates and the ploughing to shearing transition of soda-lime glass have been investigated.     

高效液相色谱-原子荧光光谱联用测定水中形态砷

采用高效液相色谱-氢化物发生-原子荧光光谱联用技术测定水中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(V)]等4种形态砷,以磷酸盐缓冲溶液为流动相,硼氢化钾为还原剂,优化了仪器主要技术参数.As(Ⅲ)、DMA、MMA和As(V)在7 min内实现了良好的基线分离,在5.00 μg/L～...     

Characterisation and Nanomechanical Properties of Ink-Jet Media Using Atomic Force Microscopy

Commercial inkjet media is increasingly used in daily life; this use ranges from offices to digital photography. The impact that the development of this technology has had on the paper industry has been phenomenal. However, an increasing amount of paper is discarded and it is often after the introduction of complex chemical ink within its substrate. The understanding of the interactions between the layer of coated media and ink can be used to further understand and develop technology for the use of recycling office and photo papers. This paper presents the innovative concept in characterizing the surface of the inkjet media by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Comparisons are made between the data obtained from both atomic force microscopy and scanning electron microscopy of the receptive layer and surface analysis software that was used to obtain surface characteristics. In this study the hardness and force of interaction has also been examined by the means of nanoindentation measurements using silicon nitride cantilever tips and forces of interaction between a selection of colloid probes and the receptive layer of the inkjet media. The effect of loading force on indentation was studied in terms of approach of impact and type of media tested.     

活化褐煤处理含酚污水的研究

褐煤经活化后，对污水中的酚有较强的吸附作用，其吸附性能与褐煤的活化条件等有关．同时，它对污水中ＣＯＤ亦有一定的去除作用．     

氢化物原子荧光法同时测定水中的硒和汞

采用氢化物一原子荧光法，应用AFS-2202a型双道原子荧光仪联合测定水中的硒和汞，方法的检出限为：Se0．31μg／L、Hg0．01μg／L，线性范围为：Se0-20．0μg／L、Hg0～2．00μg／L。     

水体有色溶解有机质的研究进展

有色溶解有机质（CDOM）是溶解有机质（DOM）的重要组成部分,它影响着碳的生物地球化学循环,为水生微生物提供重要的碳源和能源。文章介绍了国内外CDOM的研究进展和动态．主要包括CDOM的紫外吸收光谱研究,荧光光谱研究,并对CDOM中主要成分的荧光峰位置及峰值变化、来源进行论述．最后对CDOM的研究重点作了展望。     

原子荧光法测定水中锑的不确定度

对原子荧光法测定水中锑的不确定度进行评定,分析不确定度的来源,计算出该方法的扩展相对不确定度为2.4%。