925镍基合金和110SS钢在高温高酸性环境中的电偶腐蚀行为

目的 探究镍基合金925和抗硫油管管材110SS在不同面积比下耦接后的电偶腐蚀行为和电偶腐蚀效应,模拟国内某油气田高温高酸性腐蚀环境。方法 采用浸泡腐蚀试验和电化学测试技术,评价电偶腐蚀的阴阳极过程对腐蚀进程的影响,并利用扫描电子显微镜(SEM)、X射线能谱仪(EDS)与X射线衍射仪(XRD)对腐蚀试样的表面形貌及腐蚀产物成分进行分析。结果 110SS的自腐蚀电位远远低于925,阴阳极分别以1:1、1:5、1:10、1:30四种面积比耦接后,均发生电偶腐蚀。耦接后110SS的腐蚀速率分别为:0.7564、0.7032、0.6457、0.6289 mm/a,均为极严重腐蚀。结论 电偶腐蚀速率和电偶腐蚀效应均随着阴阳极面积比的增大而增加。镍基合金与碳钢油管耦接主要对材料在腐蚀环境下的腐蚀进程有影响,而对腐蚀产物和腐蚀机理的影响不大。     

改性生物炭对Ni~(2+)和Cu~(2+)的吸附

以废弃松木屑为原料制备了生物炭,采用六亚甲基四胺(HMTA)和/或CO2对其进行改性,并将其用于水中Ni2+和Cu2+的吸附。表征结果显示,以HMTA和CO2共同改性的生物炭BC1的表面积最小但表面含氧官能团含量最高。实验结果表明:生物炭经改性后,其吸附性能明显提高,且以BC1为最优;在不调节溶液p H、初始重金属离子质量浓度为50 mg/L、吸附剂加入量分别为2.0 g/L和1.0 g/L、吸附时间分别为360 min和240 min的优化条件下,BC1对Ni2+和Cu2+的去除率分别达到99.81%和95.88%;改性生物炭对Ni2+和Cu2+的吸附过程可以用Langmuir等温吸附模型来描述,而其吸附动力学具有拟二级动力学方程特征。     

聚乙烯醇缩-5-甲酰基-2,4-二羟基苯偶氮安替比林液-固萃取和光度测定镍的研究

本文报道了2,4-二羟基-5-安替比林偶氮苯甲醛(DAP)及DAP与聚乙烯醇(PVA)的缩合产物(PV·DAP)的合成.并利用PV·DAP做萃取剂,析相萃取和光度测定了铝合金和环境水样中的镍.实验结果还表明,高分子显色剂与相应的小分子试剂相比,在液-固萃取方面表现为易获得高萃取率且不受萃合物电性的影响,在光度测定方面则表现出较高的灵敏度和稳定性.从而说明试剂的高分子化可改善其性能.     

Elemental uptake by edible herbs and lettuce (Latuca sativa)

The total concentration of toxic elements (aluminum, cadmium, chromium and lead) and selected macro and micro elements (iron, manganese, copper and zinc) are reported in six leafy edible vegetation species, namely lettuce, spinach, cabbage, chards and green and red types of Amaranth herbs. Although spinach and chards had greater than 125 mv of iron, both the amaranthus herbs recorded > than 320 μ g g^{? 1} dry weight. In both the spinach and chard species, the Mn and Zn levels were appreciable recording > 225 μ g g^{? 1} and 150 μ g g^{? 1} dry weight, respectively. Aluminum concentrations were (in μ g g^{? 1} dry weight) lettuce (10), cabbage (11), spinach (167), chards (65), amaranthus green (293) and amaranthus red (233). All the micro and macro elements and the toxic elements (Ni, Cr, Cd and Pb) elements analyzed, were below the recommended maximum permitted levels (RMI) in vegetables. Further the elemental uptake and distribution of the nine elements, at three growth stages of the lettuce plant grown on soil bed under controlled conditions are detailed. In the soil, except for iron (16%), greater than 33% of the other cations were in exchangeable form. Generally in the lettuce plant, roots retained much of the iron (> 224 μ g g^{? 1}) and aluminum (> 360 μ g g^{? 1}), while leaves had less than 200 μ g g^{? 1} of iron and 165 μ g g^{? 1} of Al. Although the concentrations of elements marginally decreased with growth, the lettuce leaves had significant amounts of Mn (30 μ g g^{? 1}), Zn (50 μ g g^{? 1}) and Cu (3.6 μ g g^{? 1}). Some presence of lead in leaves (2.0 μ g g^{? 1}) was noticed, but all the toxic and other elements analyzed were well below the RMI values for the vegetables.     

Ascorbic acid, β-carotene,sugars, phenols,and heavy metals in sweet potatoes grown in soil fertilized with municipal sewage sludge

Municipal sewage sludge (MSS) used for land farming typically contains heavy metals that might impact crop quality and human health. A completely randomized experimental design with three treatments (six replicates each) was used to monitor the impact of mixing native soil with MSS or yard waste (YW) mixed with MSS (YW +MSS) on: i) sweet potato yield and quality; ii) concentration of seven heavy metals (Cd, Cr, Mo, Cu, Zn, Pb, and Ni) in sweet potato plant parts (edible roots, leaves, stem, and feeder roots); and iii) concentrations of ascorbic acid, total phenols, free sugars, and β-carotene in sweet potato edible roots at harvest. Soil samples were collected and analyzed for total and extractable metals using two extraction procedures, concentrated nitric acid (to extract total metals from soil) as well as CaCl₂ solution (to extract soluble metals in soil that are available to plants), respectively. Elemental analyses were performed using inductively coupled plasma mass spectrometry (ICP-MS). Overall, plant available metals were greater in soils amended with MSS compared to control plots. Concentration of Pb was greater in YW than MSS amendments. Total concentrations of Pb, Ni, and Cr were greater in plants grown in MSS+YW treatments compared to control plants. MSS+YW treatments increased sweet potato yield, ascorbic acid, soluble sugars, and phenols in edible roots by 53, 28, 27, and 48%, respectively compared to plants grown in native soil. B-carotene concentration (157.5 μg g^?1 fresh weight) was greater in the roots of plants grown in MSS compared to roots of plants grown in MSS+YW treatments (99.9 μg g^?1 fresh weight). Concentration of heavy metals in MSS-amended soil and in sweet potato roots were below their respective permissible limits.     

活性炭阴极电化学法回收废水中Ni(Ⅱ)的研究

研究了采用活性炭阴极电化学法,回收废水中的Ni(Ⅱ)生产硫酸镍的工艺。着重探讨了电流密度、Ni(Ⅱ)的初始浓度、溶液的pH值与反应温度对Ni(Ⅱ)回收率的影响。在电流密度为0.05A/cm2,废水中Ni(Ⅱ)的含量为250 mg/L,溶液pH值为6.0、温度为30℃及反应时间为150min条件下,废水中的Ni(Ⅱ)回收率达99.2%。     

金属泡沫镍负载纳米TiO2光催化降解甲醛和VOCs

采用溶胶-凝胶法制备了3种掺杂金属离子的纳米TiO₂光催化剂,并将其负载于泡沫镍板上,以室内空气典型污染物甲醛和VOCs为模型反应物,研究了对甲醛和VOCs气体的光催化作用并讨论了La³⁺的最佳掺杂比例以及环境因素对光催化效率的影响.结果表明:该TiO₂催化剂具有良好的锐钛矿型结构;负载掺La 1.5%TiO₂的泡沫镍板90min对甲醛和VOCs的降解率分别为94%和87%,远高于未掺:83%和72%,掺Fe     

某公司镀镍线废水回收利用研究

某公司对镀镍线产生的含镍废水,依据废水的性质和来源,进行分类回收利用。对逆流漂洗废水采用槽边回用的方式,经离子交换处理后回用于逆流漂洗槽;对综合废水收集处理,对部分出水经深度处理后,回用于镀镍线前处理、废气净化以及废水处理药剂配制等,实现水资源的节约。通过废水的回收利用,公司实现节水400 m3/d,减少废水处理量220 m3/d,减少废水排放量约300 m3/d,具有较好的环境效益和经济效益。     

土壤镍污染植物修复的研究概况

随着工业、农业活动的发展,重金属镍污染已引起国内外广泛关注。生物体内积累过量的镍会导致细胞结构和生理过程发生改变,从而阻滞生长发育,对动、植物造成不良影响。植物修复是近年来治理土壤重金属污染的重要手段之一,治理镍污染土壤的主要植物修复方法有植物吸收、植物提取、植物根系过滤和植物-微生物联合修复。而对镍超富集植物收获物的处理方法目前采用多种传统方法的复合工艺,除了克服传统方法的缺点,还能对镍加以回收,提高了资源利用化。     

影响镍在新疆荒漠土壤中形态分布因素研究

选择新疆荒漠区某石化污水库周边土壤作为研究对象,采用室内静态吸附和Tessier连续提取技术对影响供试土壤中镍的形态分布和生物有效性因素进行研究。实验结果表明,在100-400 mg/L浓度范围内,随着土壤中加入镍离子量的增加,镍的碳酸盐结合态和铁锰氧化态比例降低,生物有效性系数K呈递减的趋势,当浓度大于250 mg/L时,这种递减趋势趋于平缓;土壤pH值增大,镍的残渣态比例升高,在pH值小于8范围内,生物有效性系数K减小趋势不明显,当pH值大于8时,生物有效性系数K急剧下降;土壤环境离子强度小于0.01 mol/L时,镍的形态分布变化较小,但当离子强度大于0.01 mol/L时,镍向不易被植物吸收的形态转化。