共查询到19条相似文献，搜索用时 218 毫秒
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本文研究了重金属捕集剂-2,4,6-三巯基-1,3,5-三嗪三钠（TMT-18F）对银离子的捕集效果,讨论了TMT-18F的用量、溶液pH、反应时间这三个因素对捕集效果的影响。实验表明,TMT-18F在pH=4的溶液中,室温静置30min后,银的去除率达99％以上,且废水中银离子剩余浓度远远低于国家排放标准,说明TMT-18F对银离子的捕集效果很好。这使得TMT-18F在银离子废液处理和回收领域具有广阔的潜在应用前景。 相似文献
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实验室废液成分复杂,毒性较大,理应进行有效处理,但目前实验室废水不经处理直接排放已为普遍现象,对水质和环境造成严重污染。本文主要研究用TMT-18F处理无机实验室废水中银、汞、铅、锰离子的效果及探讨最佳处理条件。 相似文献
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实验室废液成分复杂,毒性较大,理应进行有效处理,但目前实验室废水不经处理直接排放已为普遍现象,对水质和环境造成严重污染。本文主要研究用TMT-18F处理无机实验室废水中银、汞、铅、锰离子的效果及探讨最佳处理条件。 相似文献
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2-羟基-4-磺酰氨基苯-3-(4-硝基苯)-三氮烯的合成及与汞的显色反应 总被引：1，自引：0，他引：1
合成了新的三氮烯试剂———2-羟基-4-磺酰氨基苯-3-(4-硝基苯)-三氮烯。研究了在TritonX-100表面活性剂存在下与汞的显色反应。在pH=10.0~11.0的Na2B4O7-NaOH缓冲溶液中,该试剂与汞形成2:1型浅黄色配合物。配合物的最大吸收峰位于λ=535nm处,表观摩尔吸光系数为1.21×105L?mol-1?cm-1。Hg2+的浓度在0~12μg/25mL范围内符合比尔定律,相关系数r=0.9994。该方法的检出限量为0.5μg/25mL。用拟定方法测定工业废水中的汞,五次测定的RSD<3%,加标回收率为98.2%~102.5%。 相似文献
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Meso-四-(3-5-二溴4-羟基苯)卟啉分光光度法测食品中铅含量 总被引：1，自引：1，他引：0
以食品为对象,研究了铅与Meso-四-(3-5-二溴-4-羟基苯)卟啉[T(DBHP)P]的配合反应,并对于溶液pH值、加热时间、表面活性剂用量、显色剂用量等对配合物的生成及稳定性的影响进行了探究,确定反应的最佳条件.经试验,当8-羟基喹啉存在时,铅在碱性条件下可与T(DBHP)P反应生成1:2的橙黄色化合物.该化合物在479 nm处有较强的吸收,当铅含量在0～12 μg/mL时,测得的曲线呈线性关系,服从比尔定律,重复性较好.经分光光度计测出其吸光度,绘制标准工作曲线,计算出铅的含量.结果表明:本实验所采用方法简便快速、安全,对环境污染小,且灵敏度较高,选择性较好,样品不需要分离出干扰离子,只需加入掩蔽剂即可消除钙离子和铁离子的影响.将该方法用于测定食品中铅的含量,取得了较满意的效果. 相似文献
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本文报道了一种用化学修饰电极测定水中铅离子的新方法.实验过程中,各种实验参数如电解质种类及酸度、修饰剂用量、富集电位和时间、扫描速度得到一定的优化.在pH=4.0的HAc-NaAc缓冲溶液中,铅离子与8-羟基喹啉生成螯合物富集在电极表面,然后在-1.0V被还原成零价的铅,在向阳极电位扫描的过程中,还原的铅被氧化而从电极表面溶出,出现阳极溶出峰,根据溶出峰电流可测定痕量铅离子.实验测得铅的线性范围为1×10-8mol/L至5×10-5mol/L,检测限为1×10-11mol/L.在5×10-7mol/LPb(Ⅱ)试液中,连续测定3次的标准偏差为6.3%. 相似文献
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王云芳 《咸阳师范学院学报》2006,21(2):32-36
研究了双-[3-(三乙氧基)硅丙基]硫化物(BTESPT)偶联剂的水解稳定性,采用正交试验法确定出影响BTESPT水解的主要因素是溶液的pH值,通过电导率仪和傅立叶红外光谱(FTIR)监测BTESPT的水解过程,可以看出BTESPT水解较为缓慢,需要大约50￣60h才能达到水解平衡。最后,用FTIR和电化学阻抗谱(EIS)法分析了BTESPT溶液的固化过程,结果表明:高温固化比室温固化进行地较为彻底;BTESPT水溶液固化后膜层结构致密,对金属具有很好的防护作用。 相似文献
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张书贵 《安徽科技学院学报》2001,(4)
为评价土壤重金属 (铅、镉、汞、砷、铬 )污染 ,选择芜湖市郊区农田进行土壤的采样分析。结果表明土壤环境问题以汞污染最突出 ,铅次之。土壤环境质量基本上未受到镉、砷、铬的影响。汞污染的主要原因 ,可能与当地长期使用含汞农药有关。一些土壤受铅污染的主要原因是汽车尾气所致。 相似文献
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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
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运城盐湖是典型的地质遗迹,含有大量珍贵的矿物、微生物及其他资源,因而,盐湖资源的环境状况对及产品质量与可持续利用意义重大。本文以盐湖中重金属铅、镉、汞的检测为研究对象,用原子吸收法测定铅和铬的含量,通过分子荧光法,利用汞与对羟基苯甲醛缩邻氨基苯甲酸（HBAA）荧光剂络合能使HBAA的荧光强度减低来测定汞的含量。实验结果显示,铅的线性范围是10．00～40．μg／mL,回收率在93．0％．102．3％之间,镉的线性范围是2．00～8．00μg／mL,回收率为95．3％～99．7％,汞的线性范围是0．010—0．025μg／mL,回收率为94．0％-97．9％,用以上方法测定重金属含量在本文中是可行的。实验数据表明样品中的重金属含量超标,盐湖资源面临严峻的环境挑战。 相似文献
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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
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ZHANG Ming-kui ZHENG Shun-an 《浙江大学学报(A卷英文版)》2007,8(11):1808-1815
Soils can often be contaminated simultaneously by more than one heavy metal. The sorption-desorption behavior of a metal in a soil will be affected by the presence of other metals. Therefore, selective retention and competitive adsorption of the soils to heavy metals can affect their availability and movement through the soils. In this study, the simultaneous competitive adsorption of four heavy metals (Cd, Cu, Hg, and Pb) on ten agricultural soils collected from the Changjiang and Zhujiang deltas, China was assessed. The results showed that the competition affected the behavior of heavy metal cations in such a way that the soils adsorbed less Cd and Hg, and more Pb and Cu with increasing total metal concentrations, regardless of the molar concen- tration applied. As the applied concentrations increased, Pb and Cu adsorption increased, while Cd and Hg adsorption decreased. The adsorption sequence most found was Pb>Cu>Hg>Cd. The maximum adsorption capacity for the heavy metal cations was calculated, and affected markedly by soil properties. The results suggest that Hg and Cd have higher mobility associated to the lower adsorption and that Pb and Cu present the opposite behavior. Significant correlations were found between the maximum adsorption capacity of the metals and pH value and exchangeable acid, suggesting that soil pH and exchangeable acid were key factors controlling the solubility and mobility of the metals in the agricultural soils. 相似文献
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运用反距离加权插值法、三角线性插值法、Hermite插值对法同一地区的8种重金属的空间分布进行了插值分析,并对结果进行分析对比,发现该地区除汞适合三角线性插值法以外其他均适合反距离加权插值方法.证明了重金属分布的含量与特点决定了插值方法的选取,进一步丰富了插值法对重金属的空间分布实际应用,并结合区域的功能进行分析,使空间分布更能结合于实际应用. 相似文献