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1.
香蒲植物净化塘对矿山废水的净化效益 总被引：7，自引：0，他引：7
通过对某矿山香蒲植物净化塘中的泥样、水样、植物样重金属污染物含量的测定，说明香蒲植物净化塘对矿山废水中的重金属污染物有较强的净化作用．而且香蒲植物吸收重金属污染物的能力是根＞地下茎＞叶，并有向叶转化积累的趋势．以宽叶香蒲（ＴｙｐｈａＬａｔｉｆｏｌｉａＬ）为优势种的净化塘对矿山废水中的重金属污染物具有综合净化效益，有较强运用前景 相似文献
2.
尼罗河与古埃及文明 总被引：1，自引：0，他引：1
李卫星 《长江工程职业技术学院学报》2002,19(2):53-55
尼罗河几乎是独立地哺育了人类最早的古埃及文明。阐述了尼罗河在古埃及文明的产生、发展、衰亡的历程及其对文明的各方面影响。 相似文献
3.
以1年龄桐花树为材料,用完全营养液和不同浓度的煤矸石完全营养液浸出液进行栽培试验,对不同生长阶段的桐花树根形态指标及Cu、Zn、Mn含量进行测定和分析.结果表明:以5kg、10kg、20kg、30kg煤矸石粉分别加完全营养液配成30L培养液(分别标记为:A、B、C、D),其污染水平均超过国家I类水质的标准.其中Cu、Zn未超过II类水质标准,Mn超过II类水质标准.且煤矸石含量越高,污染也越严重.桐花树根部重金属含量的变化趋势是Mn含量较高,Zn含量次之,而Cu含量较低.且桐花树根部的Mn、Zn含量随着煤矸石浸出液浓度的增大而升高.桐花树根系在煤矸石浸出液中能够正常生长发育,表明其对煤矸石浸出液的耐性较强.试验表明桐花树对Mn、Zn是富集植物,可以考虑其作为净化污水的植物. 相似文献
4.
INTRODUCTION Regulation, handling and bioremediation of hazardous materials require an assessment of the risk to some living species other than human being, or assessment of hazard to the entire ecosystem. As- sessment endpoints are values of the ecosystem that are to be protected and are identified early in the analysis. Such endpoints may include life cycle stages of a species and reproductive or growth patterns. Ecosystem risk assessment is at its dawn with this area of environment sci… 相似文献
5.
Reconfiguration is the key to produce an applicable ternary optical computer (TOC). The method to implement the reconfiguration
function determines whether a TOC can step into applied fields or not. In this work, a design of the reconfiguration circuit
based on field programmable gates array (FPGA) is proposed, and the structure of the entire hardware system is discussed. 相似文献
6.
Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops 总被引：3，自引：0，他引：3
Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely： inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil （total or bioavailable concentration） that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include： soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity. 相似文献
7.
Daqing Wetland was contaminated by heavy metals for holding lots of industrial and domestic waste water. Due to their high stability and non-degradation, heavy metals are possible to gather in human body through the food chain and then threaten health. Water samples were collected from Longfeng Wetland and lake marshes in the vicinity of Daqing City. The contents of heavy metals （Cd, Pb, Cr, Cu, Zn, Ni） were determined, and the contamination degrees were evaluated simultaneously. The results indicate that heavy metals of Zn, Ni, Cd, Cr and Pd have contaminated the Longfeng Wetland severely. In addition the concentrations of Cr and Cd in some lakes around oil wells are excessively high, and have overrun the grade V based on the threshold values of surface water given by the National Environmental Protection Agency of China. Some measures have to be taken to tackle heavy metal contamination of Longfeng Wetland and lake marshes in Daqing City. 相似文献
8.
重金属的排放造成了严重的环境问题。而消除重金属污染成为世界性的难题．有关研究结果表明。虽然重金属污染对植物有毒害作用，但是某些特殊植物具有从污染环境中吸收、转移以及积累重金属的潜能。从而修复土壤和水体等环境中的重金属污染．植物修复技术的出现虽然有很好的应用前景，但仍存在一些问题。 相似文献
9.
Study on heavy metal concentrations in river sediments through the total amount evaluation method 总被引：1，自引：0，他引：1
A quantitative method to evaluate the amounts of heavy metals in river sediments is established. Using the BT Drainage River
in North China as a study object, six representative cross sections were selected for measurement of heavy metal indicators
in sediments, and then the main contamination indicators were determined by performing a potential ecological risk assessment.
Using a section of this river as an example, the total amounts of the main pollution indicators and those of their harmful
forms are estimated by the Surfer software, which simulates the pollution status within the downstream sediments of the outfall
at this section. The calculation results could provide a theoretical guideline and data support for pollution treatment of
the BT Drainage River. 相似文献
10.
刘丹萍 《郧阳师范高等专科学校学报》2013,33(3):4-6
重金属是引起水体污染的重要因素,将对环境及社会生活带来灾难性后果.综述目前水体中重金属检测所使用的一些技术手段.着重介绍电化学方法在检测水体中重金属离子的原理、方法和该法的优势特点. 相似文献
11.
BCR法研究铜矿区周边农田重金属形态分布 总被引：4，自引：0，他引：4
采用BCR(community bureau of reference)连续提取法对梅县玉水铜矿区周边农田土壤重金属Cu、Pb、Zn和Mn的形态分布及其生物有效性进行了分析.结果表明,矿区下游地区农田土壤重金属污染比上游严重,属于重污染区,而上游土壤属于轻度污染.矿区上游和下游农田土壤中,Pb的污染贡献最大.上游和下游土壤中Cu、Zn、Mn都主要分布在残渣态中,Pb主要分布在可还原态.上游和下游土壤中都以Pb的有效性最高,Zn的有效性最低. 相似文献
12.
岷江是成都平原的母亲河。当都江堰的调控力与岷江水势相平衡时,是兴利的最佳时刻;当岷江自然伟力超过都江堰的调控力时,岷江洪水就会给成都平原带来洪涝灾害,并损毁都江堰水利工程设施,有的洪灾甚至又进一步引起成都平原的旱灾。二千余年来,这类灾害常有发生,并有日益严重的趋势。本文试对成都平原上的旱涝灾害作一历史考察,以资当今对这一问题作正确的环保风险评估,并采取相应的对策以改善成都平原的生存环境。 相似文献
13.
利用等离子质谱(ICP-MS)及X射线荧光光谱(XRF)等分析技术对湘江湘潭段沉积物的重金属元素进行了系统的分析测定。结果表明:河岸沉积物中富集着多种重金属元素,其中湘潭入河处河岸沉积物中明显富集Sc、Cu、Zn、Pb等元素;出口处沉积物中存在着U、Cr、Ni、Ba等8种元素明显富集的现象;多种原因致使Mn、Pb在出口处沉积物中富集更加明显。Hankanson潜在生态危害指数法显示:大部分代表性重金属元素(如Mn、Co等)在湘潭段河岸沉积物中存在轻微的生态危害;Cr在XS沉积物中有极强生态危害风险(Eir=423.68),在ZB中也存在很强的生态危害风险(Eir=318.68)。 相似文献
14.
通过水力学模型试验,研究了春堂坝水电站引水枢纽的两个布置方案对过流能力、建筑物下游流速、河床冲刷及右岸边坡的影响。结果显示建筑物下游存在局部掏刷问题,右岸边坡坡脚也有一定冲刷,建议在进行建筑物设计时予以重视。 相似文献
15.
以乌江枸皮滩水电站高拱坝为实例,把坝基与拱座岩体中地质缺陷作为研究对象,根据拱坝应力影响范围内的地质缺陷分布情况,通过非线性有限元法计算地质缺陷对大坝变形影响程度. 相似文献
16.
李香兰 《中国现代教育装备》2010,(3):111-113
文章通过分析pH值、水样温度、缓冲溶液、铬黑T指示剂、滴定速度、溶液中二氧化碳含量、重金属和氧化物等干扰因素对测定水中总硬度结果准确度的影响,提出相应的解决办法,从而提高水中总硬度测定的准确性。 相似文献
17.
浙江某热电厂工程2×300MW供热机组原水净化站以工业园区污水处理厂中水及河网地表水为原水,采用＂高密度沉淀池＋空气擦洗滤池＂处理工艺,设计总处理规模为11.52万m3/d,其中一期工程规模为5.76万m3/d。文章介绍了工程的设计与运行情况,着重介绍了高密度沉淀池的设计参数与构造。运行结果表明,工艺运行情况稳定,出水水质达到设计要求。 相似文献
18.
目的研究重组人白细胞介素-2（rhIL-2）的聚乙二醇（PEG）修饰物的分离纯化方法,分析修饰产物的体外理化性质。方法采用PhenylSepharose6FastFlow疏水层析和Superdex75Prepgrade分子筛层析分离纯化PEG—rhIL-2,将rhIL-2与PEG—rhIL-2分别进行热稳定性、胰酶消化和水溶性实验,不同时间取样测定活力保留。结果得到了2分PEG修饰rhIL-2的修饰产物,分子量为27000,且产物的热稳定性,抗胰酶能力和水溶性都有明显提高。 相似文献
19.
以福寿螺为研究对象,测定其在Zn^2＋浓度分别为0、1、2、5、10mg／L时,于不同暴露时间（12、24、48、96h）内,肝脏超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和丙二醛（MDA）活性的变化．结果表明：低浓度（1、2mg／L）的Zn^2＋处理组在24h内对福寿螺肝脏SOD活性起到诱导作用;随着时间的延长活性逐渐减弱,在96h时下降至最低值,极显著低于对照组水平;而中、高浓度（5、10mg／L）处理组酶活性均低于对照组．在各浓度组的胁迫下,CAT活性在12h时升高到最大值,之后随着时间的延长均表现为下降趋势．MDA含量在整个试验期间均处于诱导状态,并且与重金属浓度成正比,在10mg／L96h时达到最大值．Zn^2＋会对福寿螺产生明显的氧化胁迫,SOD、CAT和MDA指标能有效评价Zn^2＋对福寿螺的氧化损伤． 相似文献
20.
对香蕉园土壤与灌溉水添加Cd、Hg、As、Pb、cr、cu重金属元素,研究该重金元素对香蕉生长影响,以及香蕉叶片对该重金元素的富集能力。结果表明：当重金属的浓度累集到一定值时,会对香蕉的生长发育产生抑制作用,浓度太高会造成香蕉的生长停滞甚至死亡。随着土壤中Pb、Cd、As、Hg、cr、Cu重金属含量的增加,香蕉叶片中富集的重金属含量和富集系数表现为正相关的递增,香蕉叶片富集系数为Cr〉Cd〉Hg〉As〉Cu〉Pb,重金属的添加量与香蕉叶片体内含量的相关系数（r）分别为0．9630～0．9994、0．9128～0．9983。 相似文献