Effects of uncontrolled particulate matter release on precipitation under warfare conditions

This study has shown theoretical, observed and experimental evidence of pollutants released, transported and deposited during the Kosovo conflict in 1999 and their effects on precipitation in Serbia. The greatest bombardment of the chemical industry, oil refineries and fuel storage in Serbia which occurred during April, resulted in releases of many hazardous, toxic and cancerogenic substances. The number of April's days with precipitation greater or equal to 0.1 mm in 1999 are compared to those in the period from 1961 to 1990 registered at thirty meteorological stations in Serbia and especially at the Belgrade-Observatory station in the period from 1888 to 1995. The maximums of days with precipitation greater or equal to 0.1 mm were at the wider Belgrade area and at the central and southwestern parts of Serbia during April 1999. This is confirmed by using the Eta trajectory analysis.     

H2O2 formation from photocatalytic processes at the ZnO/water interface

The paper focuses on the production of H2O2 by photocatalysis over ZnO in an aerated aqueous phase. The presence of different reductants that increase the H2O2 production in the aqueous phase is analysed; particular attention is paid to nitrite, which has been shown to be the reductant that produces the most significant increments in the H2O2 production. The photocatalytic anodic decomposition of ZnO in the presence of the different reductants is also investigated. From the results obtained, the relevance of the ZnO photocatalysis in the formation of environmental hydrogen peroxide is estimated.     

Speciation of heavy metals in estuarine sediments in the northeast of Brazil

An analytical procedure involving a three-step sequential extraction was used to determine the chemical association of heavy metals (Zn, Cr, Mn and Fe) with the major phases (exchangable, reducible and oxidizable) in samples from a fishpond of estuarine sediments. The pond is located in the Capibaribe River estuary, within the boundaries of the city of Recife, in the State of Pernambuco in the northeast of Brazil. The total metal content was determined as well. All metals were extracted from the residual fraction at a percentage greater than 50%.     

铁屑置换沉淀海绵铜动力学研究

从动力学角度研究了铁屑置换沉淀海绵铜的化学反应机理,探讨了溶液pH,Cu2+初始浓度,振荡强度和温度等因素对铜置换率的影响及动力学模型。通过测定不同温度条件下的表观反应速率常数(k);求得置换反应活化能为16.21kJ/mol。试验结果表明,置换反应的所有动力学数据服从一级反应速率规律,置换过程符合扩散控制机理。     

模拟沉积磷迁移转化行为的铁盐影响机制研究

室内模拟研究了沉积物中不同形态磷在不同浓度铁盐影响下,在沉积层中的垂直迁移转化行为.结果表明,分别向模拟系统投加的10 mL和50 mL的1 mol/L FeCl_3溶液,沉积层中磷的含量降低,投加30 mL的1 mol/L FeCl_3溶液时,沉积层中磷含量增加.沉积物中适当的铁盐会阻止沉积物磷向水体释放,铁盐浓度过高或过低,在一定程度上都会促进沉积物中磷的释放,实验结果对研究内源磷释放与湖泊富营养化有重要的意义.     

Testing the importance of accurate meteorological input fields and parameterizations in atmospheric transport modelling using dream - validation against ETEX-1

A tracer model, the DREAM, which is based on a combination of a near-range Lagrangian model and a long-range Eulerian model, has been developed. The meteorological meso-scale model, MM5V1, is implemented as a meteorological driver for the tracer model. The model system is used for studying transport and dispersion of air pollutants caused by a single but strong source as, e.g. an accidental release from a nuclear power plant. The model system including the coupling of the Lagrangian model with the Eulerian model are described. Various simple and comprehensive parameterizations of the mixing height, the vertical dispersion, and different meterological input data have been implemented in the combined tracer model, and the model results have been validated against measurements from the ETEX-1 release. Several different statistical parameters have been used to estimate the differences between the parameterizations and meterological input data in order to find the best performing solution.     

赤泥基纳米零价铁对多金属污染土壤修复效果

为实现重金属复合污染（Pb、Zn、Cu和Cd）土壤同步修复,构建土壤-小白菜体系,探究赤泥（RM）、纳米赤泥（RMn）以及纳米赤泥负载纳米零价铁（RMn-nZVI）这3种不同赤泥基钝化剂对Pb、Zn、Cu和Cd复合污染土壤的修复效果与机制,并考察土壤中Pb、Zn、Cu和Cd形态分布对小白菜积累Pb、Zn、Cu和Cd的控制作用.结果显示,3种钝化剂施用可显著提高土壤pH,降低土壤酸可提取态（F1）Pb、Zn、Cu和Cd含量,增加残渣态（F4）含量,最终钝化效果表现为：RMn-nZVI>RMn>RM.此外,3种钝化剂显著降低了小白菜可食用部分Pb、Zn、Cu和Cd的积累,其中RMn-nZVI处理下降低程度最高,Pb、Zn、Cu和Cd含量分别下降35.11%、45.05%、69.52%和59.63%.结果表明,纳米赤泥负载纳米零价铁新型钝化材料在重金属复合污染土壤修复领域具有一定的应用潜力.     

石墨基复合材料负载零价纳米铁吸附重金属离子的研究进展

工业废水中重金属的存在威胁着环境和人类健康,有效去除环境中的重金属离子具有重要意义.论文简要介绍了近年来石墨基复合材料负载纳米零价铁(nZVI)去除废水中重金属离子的研究,探讨了多种石墨基负载nZVI复合材料对重金属离子的吸附特性和环境条件对吸附性能的影响因素,并对其未来的研究和应用进行了总结和展望.     

海底铁锰氧化还原过程的模拟研究

本文用室内海水-沉积物平衡箱研究了沉积物间隙水中铁、锰的垂直变化分布和随时间变化的分布,Fe~(2+)随深度、时间的变化幅度大,在六个月的实验期内均是如此,而Mn~(2+)在放置三个月后即趋于稳定;Fe~(2+),Mn~(2+)产生的宏观经验动力学表明:Fe~(2+)受pH影响远比Mn~(2+)大,且随着深度的增加更为明显,Fe~(2+)在较下层产生速率大,而Mn~(2+)反之;Fe~(2+)的扩散转移是上覆海水向沉积物中转移,扩散量为-60.7ug/m~2d,Nn~(2+)转移方向相反,扩散量为1746.2ug/m~2.d。     

乳化剂OP和邻菲啰啉存在下硫氰酸钾分光光度法测定土壤有效铁和植物中的铁

在硫酸介质中，在非离子表面活性剂乳化剂ＯＰ和邻菲啉共同存在下，铁（Ⅲ）与硫氰酸钾形成红色配合物，其最大吸收波长为５２２ｎｍ，表观摩尔吸光系数为２．０７…１０￣４Ｌ／ｍｏｌ．ｃｍ，铁（Ⅲ）含量在０—５０μｇ／２５ｍｌ范围内符合比耳定律．该法操作简便、快速．选择性好，应用于土壤有效铁和植物中铁的测定．结果令人满意．