经过水泥固化的重金属废物的穿透渗漏实验

采用穿透渗漏实验方法研究了经水泥固化的重金属废物的长期渗漏行为。用由Ｐｂ＾２＋、Ｚｎ＾２＋、Ｃｕ＾２＋、Ｎｉ＾２＋和Ｃｒ＾６＋５种重金属组成的合成废物样品进行２组实验。实验研究了渗漏实验液流速、ＰＨ的变化和金属渗漏能力对固体废物长期渗漏行为的影响。     

褐煤经磺化及碱化处理对重金属离子吸附性能研究

褐煤经磺化和碱化处理对褐煤吸附重金属的性能影响显著,通过对金属离子Ｃｕ＾２＋,Ｐｂ＾２＋,Ｚｎ＾２＋,Ｃｄ＾２＋,Ｎｉ＾２＋的单组分或多组分溶液进行吸附研究,对比了吸附速率、吸附容量、吸附选择性、耐酸性以及抗干扰能力等方面的差异,探讨了磺化褐煤和碱化褐煤对重金属离子的吸附机理,指出了今后的研究方向。     

龙口褐煤对Ni^2＋,Mn^2＋,Hg^2＋等重金属离子的吸附特性

本文以龙口褐煤作吸附剂,对重金属离子Ｎｉ＾２,Ｍｎ＾２＋,Ｈｇ＾２＋的单组分水溶液进行吸附研究,探讨了吸附剂的吸附性能,影响吸附的因素和吸附机理。结果表明：褐煤对Ｎｉ＾２＋,Ｍｎ＾２＋,Ｈｇ＾２＋的吸附均表现出Ｌａｎｇｍｕｉｒ特征,ＰＨ值是影响吸附的一个重要因素。     

镍（Ⅱ）模板一缩二乙二醇双缩水甘油醚交联壳聚糖的合成及其吸附特性

以镍离子为模板剂，合成一缩二乙二西文缩水甘油醚交联的壳聚糖树脂，并研究了该类树脂对金属离子的静态吸附性能。结果表明，以模板法合成的吸附剂比非模板合成的吸附剂具有更高的吸附能力，其对Ｃｕ＾２＋，Ｎｉ＾２＋，Ｃｏ＾２＋的吸附量分别达２．５２，２．１０，１．３９ｍｍｏｌ．ｇ＾－１。     

青霉菌BS—1还原Cr^6＋的条件及影响因子

青霉菌ＢＳ－１生长时还原Ｃｒ＾６＋的条件下：最适碳源为蔗糖或糊精，最适氮源是硫酸铵，最适温度３０℃，最适ＰＨ７．０，加入一定浓度的酵母浸出物可促进该菌对Ｃｒ＾＋的还原。不同预培养条件对该菌还原Ｃｒ＾６＋无明显影响，由此认为该菌对Ｃｒ＾６＋的还原是非诱导性的Ｈｇ＾２＋，Ｃｕ＾２＋，Ｃｏ＾２＋和Ｎｉ＾２＋对ＢＳ－１生长及Ｃｒ＾２｜还在有明显抑制作用，但在ρ（Ｎａ２ＳｅＯ４）＝１００ｍｇ／Ｌ时，则对该菌     

交联壳聚糖乙酯酯冠醚对金属离子的吸附性能研究

本文合成了二苯并－１６－冠－５－氯代乙酸酯冠醚和３，５－二叔丁基－二苯并－１４－冠－４－双氯代乙酸酯冠醚 ，然后分别将之与交联壳聚糖反应，制备了交联壳聚糖二苯并－１６－冠－５－乙酸酯冠醚 和交联壳聚糖３，５－二叔丁基－二苯并－１４－冠－４－双乙酸酯冠醚，并研究了它们对Ｐｂ＾２＋，Ｃｕ＾２＋，Ｃｒ＾３＋，Ｎｉ＾２＋，Ｃｄ＾２＋的吸附性能。结果表明这两种吸附剂对Ｐｂ＾２３＋，Ｃｕ＾２＋有较高的吸附选择     

厌氧消化过程中Fe,Co,Ni对NH4^＋—N的拮抗作用

论文以血清瓶为间歇反应器,以醋酸钙为基质,研究了厌氧消化过程中甲烷菌所需要的微量金属营养元素Ｆｅ、Ｃｏ、ＮＩ（１．０ｍｇ／（Ｌ．ｄ）,０．１ｍｇ／（Ｌ．ｄ）,０．２ｍｇ／（Ｌ．ｄ）对毒性物质ＮＨ４＾＋－Ｎ的拮抗作用,研究结果表明,Ｆｅ、Ｃｏ、Ｎｉ对毒性物质ＮＨ４＾＋－Ｎ有明显的拮抗作用,而且ＮＨ４＾＋－Ｎ浓度越高,Ｆｅ、Ｃｏ、Ｎｉ对其毒性的拮抗作用越明显。     

水杨醛改性壳聚糖对金属离子的吸附性能

研究了以水杨醛改性的壳聚糖及其衍生物对Ｐｂ＾２＋、Ｚｎ＾２＋，Ｃｏ＾２＋的静态吸附性能，结果表明，该类吸附剂对Ｐｂ＾２＋，Ｚｎ＾２＋具有良了的吸附性能，其吸附量可分别达４５５．２和１０５．５ｍｇ·ｇ＾－１，并能在Ｃｏ＾２＋存在下选择吸附Ｐｂ＾２＋，Ｚｎ＾２＋。     

产中性纤维素酶芽孢杆菌Y106产酶条件优化

筛选得到一株高产中性纤维素酶的芽孢杆菌Ｙ１０６,并对其发酵条件进行了优化,麸皮能够较大幅度地促进产酶,果糖是良好的诱导物,有机氮流促进产酶的效果优于无机氮源,最优的有机氮源是蛋白胨。Ｆｅ＾３＋、Ｆｅ＾２＋、Ｎａ＾＋、Ｃａ＾２＋可以促进纤维素酶的合成,而Ｃｕ＾２＋、Ａｇ＾＋、Ｃｏ＾２＋、Ｈｇ＾２＋则对合成起遏制作用,在酶反应系统中Ｆｅ＾３＋、Ｆｅ＾２＋、Ｃａ＾２＋、Ｍｇ＾２＋能激活纤维素酶活性,Ｃｏ     

黄棕壤和红壤吸附磷酸根后对Zn^2＋和Cd^2＋次级吸附的动力学

本文用流动法考察湖北省黄棕壤和湖南省红壤吸附磷酸根后，对Ｚｎ＾２＋和Ｃｄ＾２＋次级吸附的动力学。结果表明，Ｚｎ＾２＋和Ｃｄ＾２＋的次级吸附动力学可用一级议程拟合。初级吸附的磷酸根可造成黄棕壤对Ｚｎ＾２＋和Ｃｄ＾２＋次级吸附的速率下降；而红壤对Ｚｎ＾２＋和Ｃｄ＾２＋次级吸附的快反应速率下降，慢反应速率加大。Ｚｎ＾２＋和Ｃｄ＾２＋浓度增高可加快次级吸附反应速率；升高温度也可增快次级吸附速率。扩散作用对     

螯合剂对小麦幼苗吸收金属以及土壤金属形态的效应

本文通过盆栽试验研究三种螯合剂(EDTA、[S,S]-EDDS、DTPA)对小麦幼苗吸收土壤中重金属及其它微量元素的效应,并且通过改进的BCR连续提取法分析了种植后土壤样品中金属元素的形态。结果表明:EDTA、DTPA的添加导致小麦幼苗地上部分生物量以及叶片叶绿素a含量显著下降。螯合剂的存在明显增加了Pb和Mn在幼苗根部和茎叶的富集,并增加其由根部向茎叶的传输,但对Fe和Ni的作用比较小。小麦幼苗收获时,除Zn之外,其它元素酸溶/可交换态金属含量与对照组相比均有非常显著的增加,而各元素的可还原态由于EDTA等螯合剂的添加而有明显下降。添加螯合剂的情况下,富集量与酸溶/可交换态含量之间的相关系数大大提高,且各处理组茎叶富集量与酸溶/可交换态之间呈显著(P0.05)或极显著相关(P0.01)。因此,三种螯合剂的添加主要影响的是生物可利用形态以及潜在的生物可利用形态,并且可能导致可还原态以及可氧化态向酸溶/可交换态转变,增加金属的生物可利用性,从而也增加潜在生态风险。     

相转移催化合成新型含硫氧螯合树脂

1　IntroductionAseveryoneknown ,chelatingresincontainingheteroatomsuchassulfur,nitrogen ,andoxygenpossessexcellentadsorptionandselectivitypropertiesformetalions,especiallyfornoblemetallicions.Therefore ,manyeffortshavebeendonetopreparetheabove mentionedre…     

Chelant-assisted pulse flushing of a field Pb-contaminated soil

Laboratory experiments on a lead-contaminated soil were carried out to test the effects of chelant addition on metal leachability using column tests. Tests were aimed at studying metal mobilisation upon application of two different chelating agents (ethylenediaminetetraacetic acid [EDTA] and ethylenediaminedisuccinic acid [EDDS]). Column operation was arranged to simulate a flushing treatment in which the chelating agent is applied in a pulse mode to the soil for one bed volume, while deionised water was continuously introduced for the rest of the experiment. Two different concentrations (3 and 5 mmol·kg ^?1 respectively) of the two chelating agents and a control solution (deionised water) were tested in separate experiments; pH, total organic carbon and the total concentrations of Pb, Zn, Fe, Cd, Cu and Ni were monitored during each run. A seven-step sequential extraction procedure was used to evaluate metal partitioning and concentration in the contaminated soil after treatment as a function of depth. The results showed the effect of the nature of flushing solution on the hydraulic behaviour of the columns. Metal concentrations in the leachate increased considerably upon the application of chelants, thus indicating their suitability for metal extraction from contaminated soils. In view of full-scale application of soil flushing, particular concern should also be devoted to ensuring a homogeneous distribution of the solution within the contaminated area and an efficient collection of the exhausted extracting solution, as well as to recovering and recycling the chelating agent used.     

载钯树脂对偶氮类染料的吸附降解及其产物对发光菌的毒性暴露试验

合成了表面负载金属钯的聚丙烯醛异烟酰腙树脂后,通过Q67发光菌的毒性暴露实验研究了该树脂材料对直接大红、直接天蓝和桃红等3种水溶性偶氮染料的催化降解效果及其在降解过程中对发光菌的生物毒性变化情况,并对降解结果进行了气相色谱-质谱(GC-MS)分析.实验结果表明:载钯树脂对直接大红、直接天蓝和桃红等偶氮染料具有良好的吸附...     

A comparative study of modified and unmodified maize tassels for removal of selected trace metals in contaminated water

Powdered maize tassels were studied and found to exhibit metal sorption properties due to the availability of functional groups. The tassels have a high amount of soluble organic substances that can dissolve in aqueous media, contributing to secondary pollution during a water treatment process. A chelating agent was chemically attached on the maize tassels with a view to increase the sorption capacity, minimize leaching, and enhance the tassels’ stability. Thermogravimetric analysis confirmed that modification improved their thermal stability to withstand temperatures above 600°C as well as reduced the “secondary pollution”. The modified sorbent was employed for the sorption of lead, copper, and cadmium ions in both the model solutions and the real samples. The contact time and pH were optimized after which Langmuir and Freundlich isotherms were applied to the data. The sorption capacities for Cu²⁺, Cd²⁺, and Pb²⁺ improved from 3.4, 0.8, and 1.7?g?kg^?1, respectively, to 6.3, 2.6, and 2.6?g?kg^?1 in the same order. The sorbent was shown to remove up to 95% of the metals in less than 10 min. This study has a potential application for the remediation of polluted waters.     

FTIR研究非完全脱乙酰甲壳质对金属离子的吸附机理

以傅立叶交换红外光谱(FTIR)法研究了非完全脱乙酰甲壳质(NCTS)与Cu~ (2+),Ni~(2+),Co~(1+),Zn~(2+),Cd(2+),Hg~(2+),Ag~+,Pb~(2+)等八种金属离子形成的配合物的结构特征,并对各配合物在4000—400cm~(-1)范围内的主要吸收带作了经验归属.研究结果表明,在NCTS的金属离子配合物中,除—NH_2,—OH参予了配位外,羰基((?)C=O)和酰胺基(—CONH—)亦在不同程度上参予了配位;NCTS对Hg~(2+),Ag~+的吸附过程中存在着明显的氧化还原现象,Hg~(2+),Ag~+,分别被还原为Hg_2~(2+)和Ag~0,而NCTS分子中的—CH_2OH有可能被氧化成—COOH.     

Oxidized multiwalled carbon nanotubes modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole for solid phase extraction and preconcentration of some metal ions

In this work, a new procedure for the enrichment of the trace amount of Cu²⁺, Ni²⁺, Co²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8?mL of 5.0?mol?L^?1 HNO₃. The detection limit of Cu²⁺, Co²⁺, Ni²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4?µg?L^?1, while the preconcentration factor was 63 for Cu²⁺ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.     

Comparative effects of five chelating agents on testicular toxicity in mice induced by acute exposure to cadmium

The aim of this study was to develop new antidotes for cadmium (Cd) since this metal is known to produce mammalian toxicity. N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-benzyl-D-glucamine dithiocarbamate (BGD), diethyldithiocarbamate (DDTC), 2,3-dimercaptopropanol (BAL), and ethylenediamine-tetraacetic acid (EDTA) were studied for their ability to inhibit the adverse effects induced by Cd on mouse testes. The parameters examined included concentrations of Cd, calcium (Ca), iron (Fe), and zinc (Zn) in testes, lipid peroxidation (LPO) levels in testes, lactate dehydrogenase (LDH) activity in serum and reproductive ability of male mice. Mice injected intraperitoneally (ip) with CdCl₂ (2.5?mgCd?kg^?1) after 30?min or 24?h, were then injected ip with chelating agents (400?µmol?kg^?1). Cd increased the concentrations of testicular Ca, Cd, Fe, Zn, and LPO levels as well as the activity of LDH in serum. HBGD and BGD effectively prevented the increase in above indices, and improved the reproductive ability weakened by exposure to Cd. The results suggested that HBGD and BGD are more effective detoxificants in the case of testicular toxicity in mice induced by acute exposure to Cd.