Characterizing spatial distribution and sources of heavy metals in the soils from mining-smelting activities in Shuikoushan, Hunan Province, China

The spatial variation of heavy metals in the soils in Shuikoushan mining-smelting area, Hunan Province, China, was investigated using multivariate and geo-statistic analysis. A total of 106 composite soil samples were collected in an area of about 100 km2. Concentrations of total As, Cd, Pb, Zn, Cu and Cr were measured using inductively coupled plasma mass spectrometry (ICP-MS). Arsenic and Pb were found to have a common source, indicating the same sources and spreading processes, such as aerosols and airborne particulates from smelting chimneys. Airborne sources from smelting chimneys contributed greatly to Cd in the area, which demonstrated the same dispersion pattern as As and Pb. However, two hot spots of Cd around smelters were possibly enlarged by wastewaters, demonstrating another important source of Cd in Shuikouhsan. Geo-statistic interpolated mapping demonstrated that hotspots of Zn were only found proximal to the large smelters, suggesting that Zn primarily came from the chimneys of larger smelters. The major Cu hot-spots appeared closely to the tailing dam, indicating that weathering and leaching of tailings were the major sources of Cu contamination in Shuikoushan. Our findings indicated that airborne volatile particles and aerosols contributed the most to As, Cd, Pb, Zn and Cu contamination, while Cd and Cu may also derive from the discharge of wastewater from smelters and the leaching of tailings, respectively.     

Evaluation of phosphorus removal from wastewater by soils in rural areas in China

Low-cost, easy-maintenance and high-e ciency decentralized wastewater treatment technologies are urgently needed in rural areas of China. Processes with high potential for phosphorus removal are of great interest. However, commonly used treatment methods often do not meet the strict criteria for removing phosphorus from rural wastewater. In order to search an economic and simple technology for phosphorus removal from the common bio-technologies e uent, seven soil types collected from di erent rural areas in China were investigated for their ability to remove phosphorus. X-ray di raction (XRD) was used to analyse the mineral structure, and inductively coupled plasma optical emission spectrometer (ICP-OES) was used to analyse the geochemical composition of the soil samples. Three primary minerals – quartz, albite and montmorillonite – were clearly detected. The samples were divided into two soil types, acidic soils and alkaline soils, based on their pH values. The geochemical composition study indicated that a higher percentage of Ca and Mg occurred in alkaline soils (pH > 8) than in acidic soils (pH < 6.5). Adsorption isotherms from batch experiments fitted the Langmuir and Freundlich models well, the maximum P adsorption capacities ranged from 0.256 to 1.598 mg P/g, indicating a high phosphorus removal potential for all of these soils. The P fractions extracted revealed that the sum of NaOH-extracted inorganic P (NaOH-Pi) was the major P component in the acidic soils, and CaCO3-bound phosphorus (Ca-P) in the alkaline soils. Dynamic adsorption simulation showed that these soils have the ability to remove phosphorus from wastewater.     

短信息

德国开发出"可印刷的"电池德国研究人员最近开发出了世界上首款"可印刷的"电池,它薄如纸张,用丝网印刷技术就能生产。据德新社报道,德国弗劳恩霍弗电子纳米系统研究所研发的这种"薄纸"电池每个质量不足1克,厚度不到1毫     

海水中痕量元素测定及其在重金属污染源判别方面的应用

利用电感耦合等离子体质谱(ICP-MS)研究了胶州湾及莱州湾这两个海域中痕量元素污染水平,发展了ICP-MS海水环境中痕量元素的测定方法,同时找出海水环境中具有保守性的数种元素作为污染示踪元素.达到对于海水环境中痕量污染物被动示踪的目的.对18个真实样品进行了识别率试验,识别率可达90%以上,在选取3个海水样品及1个河水样品混合后的模拟分担率实验,也取得了满意的结果,其误差平均值仅有1.17%.     

热解析-脉冲低温等离子体集成系统脱汞研究

热解析-脉冲低温等离子体集成处理系统是专门针对典型含汞废物安全处置而开发的,可以同时有效控制汞等多种复合气体污染物。通过检测热解炉后烟气中和等离子体反应器入口、出口气体中Hg0和Hg2+浓度,研究汞的价态转化及添加剂对脱汞效果的影响。结果表明:热解烟气中Hg2+/HgT为17%~45%,Hg0/HgT为55%~83%,热解温度主要影响汞价态分布,WMC添加量主要影响汞浓度值;加入添加剂会促进汞的脱除,但添加剂过量不利于汞的氧化;热解炉中添加50 g WMC和5 g升华硫添加剂时,反应器内Hg0氧化率和总汞损失率分别可达55%和42%。该研究可以为探索新型含汞废物处置工艺,实现含汞废物深度净化提供新思路。     

ICP-MS法测定含油固体废物金属元素及两种消解方法比较

比较电热板消解和微波消解两种消解方法对测定含油固体废物金属元素的影响,并通过电感耦合等离子体质谱(ICP-MS)法测定其中10种金属元素的含量。通过F检验验证两种消解方法的差异,结果表明:电热板消解和微波消解两种消解方法对测定数据准确性无显著影响,但微波消解具有精密度好、耗酸量少、不易引入污染、消解彻底、用时较短等优势。进一步对微波消解体系和ICP-MS分析条件进行优化后发现,采用HNO_3-H_2O_2-HF混合酸体系微波消解含油固体废物样品后以~(103 )Rh作为内标元素,能够有效校正含油固体废物样品基体干扰。元素检出限为0.06～1.8mg/L,相对标准偏差在2.99%～9.63%的范围内,加标回收率在89.4%～113%之间。该方法耗酸量少,灵敏度高,快速准确,能够应用于含油固体废物中金属元素的测定。     

滑动弧等离子体处理三种染料废水的研究

偶氮染料酸性橙Ⅱ、吩嗪染料中性红和三苯甲烷染料碱性艳蓝BO是3种具有代表性的常用工业染料。通过气液两相滑动弧放电等离子体产处理这3种染料,对其脱色效果、反应动力学、降解效果及降解路径进行了分析。实验结果显示:当放电电压10 k V、频率50 Hz、载气(空气)流速0.8 m~3/h、液体流速60 m L/min、染料溶液体积500 m L、浓度200 mg/L,放电处理60 min时,滑动弧等离子体对染料溶液的具有较好的脱色效果,酸性橙II、中性红和碱性艳蓝BO的脱色率分别为84.1%、72.7%与89.7%。3种染料的脱色反应符合一级反应动力学规律,其中碱性艳蓝在前30 min的脱色速率最快,可达0.0631 min~(-1),远大于酸性橙II和中性红,而后30 min的反应速率均明显放慢,低于酸性橙II和中性红的同期脱色速率。滑动弧等离子体对3种染料的降解效果(COD去除率)不高,经过60 min的处理降解率分别仅为27.4%、37.3%和28.2%。最后,通过降解过程中的UV-Vis色谱变化对3种染料的降解路径作了初步推测,即等离子体先破坏染料的发色体系与共轭体系,随后发生开环反应,最后再降解为小分子结构。     

电感耦合等离子体发射光谱法测定地下水中锰的不确定度评定

本文对电感耦合等离子体发射光谱法测定地下水中锰含量的不确定度进行了评定,标准曲线采用双误差拟合法,建立了不确定度评定模型,对测定地下水样品中锰含量的不确定度作了评估。     

等离子体分解SO2实验

介绍了在低温常压条件下,应用等离子体分解有害气体ＳＯ２的实验结果,通过实验总结出ＳＯ２浓度,气体流量以及烟气温度ＳＯ２分解率的影响规律,比较了脉冲叠加正、负直流电压产生的等离子体分解ＳＯ２的能耗和分解量。实验结果表明,该项技术耗能低,ＳＯ２分解率高。每消耗１ｋＷ·ｈ电能可分解１．６１－１．９７ｋｇＳＯ２气体,分解率达８０％以上。     

等离子体烟气脱硫技术现状与关键问题讨论

介绍了ＳＯ２的３条去除路径,高能电子的解离还原路径;自由基的氧化路径;以及与氨的热化学反应路径。提出ＳＯ２浓度测试要先去氨及ＮＯＸ测试先去ＳＯ２的方案。分析了温度、氨量、烟气组分及供电情况对ＳＯ２去除的影响。认为ＮＯ２及硫酸气溶胶的存在促进ＳＯ２去除的作用和脱硫与除法结合问题。最后提出利用氨与等离子体的协同作用,以热化学反庆为主路径,以等离子体活化反应为补充的脱硫思路。