城市污泥的重金属生物活性及其控制

随着土壤法规的加强 ,城市污泥中的重金属严重影响着污泥的处理、处置。介绍了污泥中重金属的分配和化学形态 ,以及迄今为止几种主要的控制方法     

微生物抗重金属毒性研究进展

不少重金属是微生物正常生长的必需元素 ,但是当重金属在菌体内浓度过高时 ,会对菌体产生毒性。微生物可通过细胞的表面富集与细胞膜成分的改变减小毒性的破坏 ,在重金属进一步的诱导下 ,菌体会产生由结构基因与调节基因组成的抗性基因 ,通过多途径的联合作用对重金属的毒性进行解毒     

红萍在植物治污方面的应用研究进展

植物治污是利用植物清除土壤和水中的各类污染物 ,进行环境治理。水生蕨类植物红萍具有一定的耐污能力 ,可以通过植物活体的富集作用和干体的物理吸附作用 ,从溶液中吸附多种重金属元素及通过植物挥发作用 ,将吸入的硒盐转化为挥发态。在污水中养萍可以去除COD和进行生物脱氮除磷 ,并设计出相应的养萍盘和生物稳定塘系统进行废水处理 ;利用红萍干体填充的滤柱可以用于电镀污水中一些重金属元素吸附回收。本文对红萍近年来在植物治污方面的应用和研究进行了描述和展望     

一种新型环境矿物材料在废水处理中的应用研究

实验研究表明 ,磷矿石作为一种新型环境矿物材料对重金属离子工业废水具有较好的处理效果 ,且自身具有显著的优点。采用分级处理的方法以及磷矿石的合适用量可以使处理后的工业废水达到排放标准甚至饮用标准 ,同时 ,由于磷矿石去除重金属离子速度快 ,在瞬间即可发生作用 ,使得利用动态法进行工业废水的连续处理成为可能 ,而且不会产生二次污染 ,具有工艺应用意义     

Seasonal Fluctuation in Heavy Metal Pollution in Iran´s Siahroud River - A Preliminary Study (7 pp)

Background The management of its available water resources has become a key issue for Iran. During the last few decades, the water quality of Siahroud River in the coastal plain of the Caspian Sea in Gilan Province in Northern Iran has significantly degraded. The scarcity of water has been compounded by rapid population growth and increasing pollution from fertilizers, pesticides, and municipal and industrial wastes. One of the sources of this degradation is the movement of heavy metals from the river's watershed into the various water systems supported by the river, including the water system for Rasht City. Methods To study the magnitude of heavy metal pollution in the Siahroud River, seven heavy metals including Zn, Cu, Pb, Cd, Mn, Fe, and Ni were measured in duplicate from replicated water samples collected over five consecutive seasons and analyzed by Atomic Absorption Spectrometry. In situ measurements of pH were taken with the samples and total organic carbon (TOC) was analyzed by IR gas measurement. Results The results demonstrated that four of the seven heavy metals including Pb, Fe, Cd, and Mn exceeded permissible safe levels as established by the United States Environmental Protection Agency. Multivariate factor analysis suggested that industrial land-use was the main contributing factor for the high levels of Fe and Mn in the Siahroud River, whereas, Cd was principly from agricultural activities in the watershed. The data also suggested that pH and TOC had an important role in the behaviour of Pb and Mn, and that the elevated levels of these two heavy metals in Siahroud River was the consequence of other anthropogenic sources. Only negligible levels of Zn, Cu and Ni were detected. Finally, all the sampling stations were subjected to cluster analysis. The results indicated that three different zones could be distinguished according to the levels of pollution. In addition, it was shown that the urban areas did not have a significant impact on the heavy metal pollution in the river. This observation stems from the fact that the data from the sampling stations before and after Rasht City were not significantly different. Recommendation . Preventive measures need to be undertaken in the land-use systems and watersheds of the Siahroud River to reduce the pollution levels of Pb, Cd, Mn and Fe.     

宝应县土壤重金属的污染调查

以宝应县农田土壤重金属调查为依据，采用污染指数法对土壤质量进行评价，分析土壤重金属污染原因，提出防治措施。     

东京根霉对重金属Cr^3＋、Mn^2＋和Zn^2＋的吸附研究

利用固定化发酵中产生的废菌体——东京根霉（Rhizopustonkinesis）去除废水中Cr^3＋、Mn^2＋和Zn^2＋,研究了预处理、pH、温度、金属离子初始浓度、吸附时间等条件对吸附量的影响。结果表明，用NaOH浸泡4—6h、在pH=5—6，温度25-35℃时吸附效果最好，用Langmuir、Freundlich和Temkin方程对其吸附等温线进行拟合，相关性都比较好；用不同的吸附动力学方程描述东京根霉吸附金属离子的最优和最次模型分别为Elovich方程和一级扩散方程，双常数方程和抛物线扩散方程拟合介于前二者之间。     

酸雨对苏州市文物古建筑的影响初探

近年来，苏州市区酸雨出现频率增加，降水pH值下降，威胁着众多的文物古建筑。因此从苏州现存文物古建筑的五种材质入手，剖析酸雨对文物古建筑的影响，并对国家重点保护文物罗汉院双塔及正殿遗址典型的案例进行了剖析。     

EuroBionet: a pan-European biomonitoring network for urban air quality assessment

EuroBionet, the 'European Network for the Assessment of Air Quality by the Use of Bioindicator Plants', is an EU-funded cooperative project currently consisting of public authorities and scientific institutes from 12 cities in 8 countries. In 2000, the bioindicator plants tobacco (Nicotiana tabacum Bel W3), poplar (Populus nigra 'Brandaris'), spiderwort (Tradescantia sp. clone 4430), Italian rye grass (Lolium multiflorum italicum) and curly kale (Brassica oleracea acephala) were exposed to ambient air at 90 monitoring sites according to standardised methods. Visible injuries and growth parameters were assessed and the accumulation of toxic substances in leaves determined. The exposure of tobacco resulted in a gradient with low levels of ozone-induced foliar injury in N and NW Europe, and medium to high values in the southern and central regions. The results of heavy metal and sulphur analyses in rye grass samples generally showed low to very low sulphur and low to medium heavy metal concentrations in leaves. In some cities, however, local hot spots of heavy metal contamination were detected. Analyses of the PAH contents in curly kale leaves gave low to medium values, with locally elevated levels at traffic-exposed sites.     

植物SOD活性变化与其抗污能力的关系

研究了模拟酸雨、ＳＯ２单独与复合污染对水杉、杉木、龙柏３种抗污能力不同的植物ＳＯＤ活性、细胞汁酸度、细胞膜透性的影响。结果表明，ＳＯＤ的活性经污染后变化规律在不同植物有所不同，而这种变化与其抗污能力有关。ＳＯＤ活性升高者，其抗污能力强，反之则弱，与本底值大小无关。