天津市土壤元素背景值的地域差异及成因分析

论述了天津土壤中Cu,Pb等13种微量元素背景值在行政区，土壤类型中的差异规律，并分析了引起元素背景值地域差异的原因。     

Exposure to Selected Heavy Metals Through Water Ingestion in an Area Under the Influence of Tanneries

This study evaluated the potential toxicological risk posed to human health due to the exposure to heavy metals by water ingestion in an area affected by tanneries – the Cadeia-Feitoria hydrographic basin (Brazil). River water was collected at 10 sites, every 3 months, from July 1999 to April 2000. After acid digestion, total metal concentration was determined by inductively coupled plasma optical emission spectrometry (Cd, Cu, Cr, Ni, Zn), flame atomic absorption (Al, Fe, Pb, Mn), or cold vapor atomic absorption spectrometry (Hg). Cr(VI) was complexed with diphenyl-carbazide and detected by UV–vis spectrometry. In order to quantify the risk of exposure, the risk assessment methodology employed by the Environmental Protection Agency of the United States was applied at a screening level. The assumed scenarios included extreme exposure patterns (ingestion of untreated water, conversion of Cr(III) to Cr(VI), temporal peaks of pollution). Fe, Al, Cd, Hg, and Pb were not included in the risk analysis, since they showed a low toxicity potential or were undetected in the samples. The selected metals presented Hazard Quotients < 1, in the following order of increasing risk: Cu < Cr(III) < Zn < Ni < Mn < Cr(VI). Hazard indexes, representing the additive effect of contaminants, were also low in the basin (< 1), but comparatively increased in the lower reach of Feitoria and Cadeia Rivers. Although noncarcinogenic risk levels did not suggest possible adverse toxicological effects to the human population, a considerable deviation from background conditions was observed downstream the area where tanneries are mainly located.     

天然水体沉积物对重金属离子的吸附特性

本文运用表面络合模式，研究了江西乐安江下游黄龙庙沉积物的吸附特性，测定了样品对重金属ＣＵ，ｃＤ的吸附等温线和ＰＨ吸附突跃曲线；应用ＦＩＴＥＱＯ程序计算了沉积物的表面固有吸附常数；对恒定容量模式，扩散层模式和三层模式在天然水体沉积物中的应用进行了比较。     

广西桂东北地区农业土壤环境若干重金属元素背景值的调查

应用分层抽样统计方法,调查研究广西桂东北地区农业土壤环境Cu、Zn、Pb、Cd、Ni、As、Cr、Hg等8种重金属元素背景值,并分别求算出各元素背景值95％的置信区间。经方差分析,各成土母质间几种元素背景值都有不同程度差异。探讨了该区域农业土壤元素背景值与世界土壤、地壳丰度和国内土壤元素背景值的差异,为开展农业环境科学研究提供依据。     

几种萃取剂对土壤中重金属生物有效部分的萃取效果

采用6种萃取剂:pH=7的0.01mol/L CaCl_2、pH=7.3的0.005mol/L DTPA+0.1mol/L TEA(三乙醇胺)+0.01mol/L CaCl_2O.1mol/L NaNO_3、0.43mol/L HOAc、pH=7的0.05mol/L EDTA和pH=4.65的0.5mol/L NH_4OAc+0.02mol/L EDTA浸取液.对污染土壤中的重金属Cu、Zn、Cd、Pb、的进行了萃取,并比较了萃取剂的萃取能力。实验结果表明,HOAc、EDTA以及NH_4OAc-EDTA萃取各种重金属的能力远远大于其它几种萃取剂的萃取能力,是比较理想的萃取剂。     

金属氢氧化物包被砂过滤柱吸附与去除水体中的微生物

以氢氧化铁与氢氧化铝原位沉积包被砂作介质的过滤柱 ,用于去除脱氯自来水中人为污染的高浓度脊髓灰质炎病毒PV1、脆弱拟杆菌噬菌体B .fp和大肠杆菌E .coli.结果显示 ,包被修饰砂颗粒表面Zeta电动势由原来的 - 4 2 .8mV上升到 5 4 .7mV ,并因此提高了对微生物的吸附去除能力 .修饰砂过滤柱经 12 .5d连续过滤 30 0L水样后 ,仍可使进水微生物浓度分别高达n(cfu) /mL-1=5 .2× 10 6、2 .4× 10 5、2 .3× 10 5的E .coli、B .fp和PV1去除 92 %、97.2 %和 99.6 % .而未修饰砂柱 ,在相同条件下仅分别去除 5 3%、5 9%和 70 .6 % .修饰砂柱可在较大pH变化下稳定高效地去除微生物且在中性条件下效果最佳 ,这与未修饰砂柱明显不同 .扫描电镜显示 ,两种砂具有明显不同的表面结构 .修饰砂柱流出液中检测不到用于包被的铁、铝金属 ,说明氢氧化铁、氢氧化铝修饰物同砂结合牢固并因此提高了砂过滤柱的使用寿命 .修饰砂过滤介质可为饮用水处理提供更为安全可靠的去除病原微生物方法 .图 4表 4参 19     

High Cu and Cd pollution in sediments from Sisimiut, Greenland. Adsorption to organic matter and fine particles

High concentrations of Cu of up to 200 mg/kg, and Cd of up to 4.0 mg/kg, were found in sediments from the aquatic environment around Sisimiut, Greenland. These concentrations are four times higher than the limiting concentration where toxicological effects are expected. The pollution could be linked to human activities in Sisimiut, a link that have not been investigated previously in Greenland. Except from the most polluted samples there was good correlation between heavy metal concentration and organic matter. Also some relationship between fine fraction and heavy metal concentration was observed.     

交联壳聚糖冠醚的合成及其对金属离子的吸附性能

本文合成了交联壳聚糖苯并－１５－冠－５醚和交联壳聚糖苯并－１８－冠－６醚,研究了它们对Ａｇ（Ⅰ）Ｐｄ（Ⅱ）,Ｐｂ（Ⅱ）,Ｃｄ（Ⅱ）,Ｃｒ（Ⅲ）等金属离子的吸附性能和选择性,实验结果表明：无论是在单一金属离子体系还是在二元或三元金属离子体系中,ＣＣＴＳ－ＢＸ和ＣＣＴＳ－ＢＹ对Ａｇ（Ⅰ）和Ｐｄ（Ⅱ）者有较高的吸附选择性。     

燃煤灰渣中微量元素分布规律的研究

研究了锅炉飞灰和底灰中１５种微量元素的含量和分布，探讨了煤炭燃烧后，微量元素在灰渣中的集散及其影响因素，飞灰和底灰中大多数元素高于全国土壤背景值，７种元素高于克拉克值，其余８种低于克拉克值，飞灰中多数元素的地球化学富集因子高于１，呈富集状态，而底灰中多数元素富集因子小于１，飞灰和底灰中微量元素含量与煤中微量元素含量呈线性关系，微量元素含量不仅与煤有关，还受锅炉燃烧方式等人为因素影响。     

东北、内蒙古东部地区煤炭中微量元素含量及分布规律

研究了东北和内蒙东部各矿区煤炭中As,Ba,Be,Cb,Co,Cr,Cu,Hg,Li,Mn,Ni,Pb,Se,Sr,V,Zn,Zr的含量水平及分布规律.煤灰灰分中多数元素含量高于克拉克值、土壤背景值及植物干物质中含量,呈富集状态.相关矩阵和聚类分析表明,煤炭中微量元素含量与基质元素有密切的依存性.由于复杂的成煤过程,煤炭中微量元素呈现独特的集散规律.