生物质固定化硫酸盐还原菌处理废水中重金属离子

采用海藻酸钠和3种生物质载体(稻壳、玉米芯、秸秆)固定化的硫酸盐还原菌(SRB)处理单一重金属(700 mg/L Fe2+, 75 mg/L Cu2+, 120 mg/L Pb2+, 80 mg/L Cd2+)废水,筛选出稻壳为效果较优的固定化载体,并对合成重金属废水(含400 mg/L Fe2+, 30 mg/L Cu2+, 50 mg/L Pb2+, 40 mg/L Cd2+)的处理效果作了进一步研究. 结果表明,稻壳固定化SRB去除单一重金属时,Fe2+, Cu2+, Pb2+, Cd2+去除率分别为99%, 100%, 100%, 100%;处理合成重金属废水时,4种重金属去除率分别为98.06%, 100%, 99.35%, 100%.     

典型重金属离子对双污泥系统反硝化除磷的影响

为了研究和比较重金属对双污泥系统的影响,在双污泥系统稳定运行的基础上,通过调节进水重金属(Cd2+、Cu2+、Zn2+)含量,分别考察了3种重金属短期冲击和长期冲击对双污泥系统碳、氮、磷去除效果的影响.结果显示,Cd2+、Cu2+、Zn2+对硝化菌的短期急毒性和抑制作用关系为Cd2+>Zn2+>Cu2+,对硝化菌的累积...     

C-S-H凝胶对Cd2+、Zn2+和Cu2+的吸附固化作用

以分析纯Ca(NO3)2·4H2O、Na2SiO3·9H2O和重金属硝酸盐为原料,通过溶液反应法分别制备钙硅比为0.8和1.8的纯净及含Cd2+、Zn2+和Cu2+的C-S-H凝胶,研究了C-S-H凝胶在形成过程中对三种重金属离子的吸附固化作用.结果表明,两种钙硅比的C-S-H凝胶均能吸附固化Cd2+、Zn2+和Cu2+,重金属离子较易进入低钙硅比C-S-H凝胶夹层结构中,可以置换高钙硅比C-S-H凝胶结构中的Ca2+,在水化液相中形成Ca(OH)2.C-S-H凝胶对Cd2+和Cu2+的固化能力好于对Zn2+的,低钙硅比C-S-H凝胶对Zn2+的吸附固化作用优于高钙硅比C-S-H凝胶.     

反渗透膜处理有色冶金酸性无机复合重金属废水

以模拟有色冶金烟气净化系统酸性重金属废水为研究对象,利用反渗透膜分离技术,探究了压力、p H、运行时间和浓淡比对膜处理Cr3+、Pb2+、Cu2+、Zn2+等重金属离子效果的影响。结果表明,优化工艺条件下,Cr3+、Pb2+、Cu2+、Zn2+质量浓度同时分别高达30 mg/L下,膜对4种重金属离子的截留仍有较好效果,截留率分别为99.8%、97.0%、97.8%和97.9%;淡水中,除Cu2+的含量只达到了GB 8978-1996中的二级标准要求外,其他3种重金属离子的出水含量均符合一级标准要求。     

Cu2+、Zn2+、Cr6+、Cd2+和Pb4+离子在水泥熟料中的固溶特性研究

通过制备未掺杂重金属以及同时掺杂Cu2+、Zn2+、Cr6+、Cd2+和Pb4+五种重金属离子的水泥熟料,利用化学分析、XRD、岩相分析、电子探针等方法研究了掺杂Cu2+、Zn2+、Cr6+、Cd2+和Pb4+离子对熟料性能的影响以及重金属在熟料矿物中的分布.研究表明:重金属的掺杂可以增加液相含量、改善生料的易烧性;在煅烧后的熟料矿物中,有巨型的阿利特矿物出现,且多被溶蚀;熟料对重金属的固化具有选择性.     

新型杯[4]芳烃衍生物对Pb~(2+),Cd~(2+)的萃取性质

研究了新型杯[4]芳烃D对Pb2+,Cd2+离子的液-液萃取性质,并将其与自制的杯[4]芳烃A及其衍生物B、C对Pb2+,Cd2+离子的液-液萃取性质进行了比较。结果表明,与化合物A~C相比,D对Pb2+萃取率最高,在实验条件下,可达到42.8%;测试的四种化合物对Cd2+离子的萃取效率均不佳,未经任何修饰的杯[4]芳烃A的萃取效率最高,仅8.5%。推测对Cd2+的萃取为阳离子交换机理。     

香豆素类荧光增强型Cu2+荧光分子探针

设计合成了含酰肼和亚胺结构的双香豆素类Cu2+荧光分子探针CCu,其结构用1HNMR、IR、HRMS和元素分析进行了表征,并考察了其光谱性能。CCu在常见碱金属离子(K+,Na+)、碱土金属离子(Ca2+,Mg2+)、过渡金属及重金属离子(Cd2+,Ag+,Fe3+,Pb2+,Hg2+,Cr3+,Co2+,Ni2+,Cu2+,Zn2+)中能够专一性地识别Cu2+。滴加Cu2+后引起吸收光谱蓝移38 nm,荧光光谱蓝移17 nm,荧光增强8.2倍,溶液荧光由无色变为蓝色。CCu对pH不敏感具有较低的pKa值(3.32±0.07),可在近中性和弱碱性范围内对Cu2+进行检测。     

磁性膨润土的制备及其性能

为实现外加磁场下膨润土处理废水后的快速分离,先以FeCl3·6H2O,FeSO4·7H2O等为主要起始原料,采用共沉淀法制备Fe3O4磁流体,再与膨润土复合制备一系列不同Fe3O4载量(质量分数,下同)的磁性膨润土。采用X射线衍射、Fourier红外吸收光谱、扫描电子显微镜、透射电子显微镜、能谱仪、振动样品磁强计对样品进行表征,研究了Fe3O4载量对磁分离回收率,Cu2+,Zn2+,Cd2+的饱和交换吸附量及去除率的影响。结果表明:Fe3O4微粒附载于膨润土表面而形成磁性集合体,磁性膨润土具有超顺磁性,对Cu2+,Zn2+,Cd2+的饱和交换吸附性能及去除率与原膨润土的相当,但随Fe3O4载量增加而降低。Fe3O4载量为25%时,其饱和磁化强度、剩余磁化强度分别为13.344,0.365A·m2/kg,矫顽力为1.232kA/m,磁分离回收率为90.1%。对浓度为5mmol/L的Cu2+,Zn2+,Cd2+的饱和交换吸附量分别为23.0,21.3,18.9mg/g,去除率分别为27.9%,26.6%,14.3%。     

新型杯[4]芳烃衍生物对Pb2+,Cd2+的萃取性质

研究了新型杯[4]芳烃D对Pb2+,Cd2+离子的液-液萃取性质,并将其与自制的杯[4]芳烃A及其衍生物B、C对Pb2+,Cd2+离子的液-液萃取性质进行了比较.结果表明,与化合物A～C相比,D对Pb2+萃取率最高,在本实验条件下,可达到42.8%;测试的四种化合物对Cd2+离子的萃取效率均不佳,未经任何修饰的杯[4]芳烃A的萃取效率最高,仅8.5%.推测对Cd2+的萃取为阳离子交换机理.     

一株解磷菌ID-a修复重金属污染土壤效应分析

采用一株解磷成团肠杆菌ID-a修复陕北某工业园区长柄扁桃种植地土壤,评价了该地区土壤重金属的污染状况,分析了修复前后土壤中重金属元素Cu,Pb,Zn,Cd存在形态的变化以及解磷菌修复对长柄扁桃叶子及果实中重金属Cu,Pb,Zn,Cd的质量分数的影响。由结果可知:工业园区土壤与未污染的对照组相比Pb,Cd,Cu和Zn质量分数分别增加了24.92,4.45,18.13,77.99 mg/kg;解磷菌修复组与对照组相比土壤中可交换态Cd,Pb,Cu的质量分数显著降低,其相应的残渣态的质量分数增加。长柄扁桃叶子中Pb,Cd和Zn质量分数分别降低了95.14%,40.63%和43.87%,果实中Cu,Zn质量分数分别降低了54.06%和35.91%,长柄扁桃果实中未检测出重金属Pb和Cd。因此,该菌剂能够修复该污染区种植地土壤,提高长柄扁桃的安全性。     

啤酒酵母对重金属离子的吸附和解吸效果影响的实验研究

以固定化的啤酒酵母作为生物吸附剂,海藻酸钠和聚乙烯醇作为包埋剂,研究了pH值、ρ(初始重金属离子)、ρ(菌体)、吸附时间、吸附温度对吸附Pb2+、Cu2+、Zn2+和Cd2+的影响,并进行了解吸剂及其质量浓度对固定化啤酒酵母解吸影响的研究.研究结果表明,在pH值=5.5,ρ(菌体)=20 g/L,吸附时间2h,吸附温度...     

改性玉米淀粉对重金属捕集性能的研究

研究了二硫代氨基甲酸改性玉米淀粉(DTCS)对单一重金属溶液中重金属离子的捕集作用,考察了影响其捕集作用的因素,包括重金属种类、pH、温度、混凝时间、无机离子的干扰等,确定了合适的应用条件.结果表明,在单一重金属离子浓度为1.0×10-3 mol/L的溶液中,DTCS对重金属离子捕集的选择性:Cu2 ＞Pb2 ＞Cd2 ＞Zn2 ＞Ni2 ,去除率分别为99.91%、99.88%、87.36%、85.17%、66.36%,且K 、Ca2 等无机离子对其去除效果影响不大.     

松果对废水中Cu~(2+)、Pb~(2+)、Zn~(2+)的吸附特性研究

以松果作为吸附剂进行了去除废水中Cu2+、Pb2+、Zn2+的吸附及解吸试验,研究了溶液pH值、吸附剂投加量、反应时间、溶液初始浓度对吸附效果的影响,以及不同pH值对达到吸附平衡的松果的解吸影响。结果表明:当pH值为5.0～5.5,Cu2+、Pb2+、Zn2+初始质量浓度约为25 mg/L时,吸附剂的最佳投加量分别为3、1.5、3 g/L,去除率分别为55.32%、86%、39.96%。3种重金属离子的吸附动力学方程符合Lagergren准二级动力学方程,R2均大于0.998。等温吸附研究表明:Freundlich方程能较好地描述Cu2+的等温吸附过程,Langmuir方程则能更好地描述Pb2+和Zn2+的吸附过程,用Langmuir方程拟合等温吸附数据得出松果对Cu2+、Pb2+、Zn2+的最大吸附量分别为9.10、31.65和9.60 mg/g。强酸是一种理想的Cu2+和Zn2+解吸剂。     

小球藻吸附水体中Cd~(2+)、Pb~(2+)和Cu~(2+)的试验研究

为了研究小球藻藻体吸附水体中Cd2+、Pb2+和Cu2+的情况,在检测了典型电子垃圾处理区水体中重金属Cd、Pb和Cu浓度的基础上,采用冷冻干燥的小球藻藻体在模拟重金属离子溶液中进行吸附试验。结果表明,水体中重金属Cu的浓度较高,Cd和Pb的污染程度较严重。藻体对于Pb2+的去除效果较好,去除率和去除量分别达到88.42%和13.262 4 mg/g;Cu2+的去除率较低,但去除量高达17.480 6 mg/g;Cd2+去除率较高,但去除量仅有0.433 7 mg/g。     

CHARACTERIZATION AND EVALUATION OF LEVEXTREL EXTRACTION CHROMATOGRAPHIC RESINS FOR TRACE METAL SEPARATION SCHEMES IN AUTOMATIC WATER QUALITY CONTROL SYSTEMS.

ABSTRACT

This paper presents the results of the selective removal of Zn(II) from Cu(II), Cd(II), Ni(II) and Pb(II) using ‘Extraction Chromatographic Resins’ Lewatit TP80T84, which contains dK2,4,4-trimethylpentyl)pbosphinic acid as active component. The extraction and selectivity patterns of the resin were obtained from the metal distribution coefficients as a fiinction of pH. Experimental data of Pb(II), Ni(II) and other natural water occurring metal ions, such as Ca(II), were analyzed graphically and numerically in order to describe the metal extraction reactions. Analysis of the results showed that the extraction of these metal ions can be explained assuming the formation of metal complexes in the resin phase with a general composition ML2(_{q 3}HL)q, where q takes different values depending on the metal studied. Finally the efficiency of the resin in the selective removal of Zn(II) from the toxic heavy metal group Cu(T±), Cd(II), Ni(II) and Pb(II) were evaluated.of divalent metal ions (Zn(II), Cu(II), Cd(n), Ni(II), Pb(n)). Concerning the extraction selectivity of Lewatit TP80784 resins versus Zn(II), Cu(II)( Cd(n), Ca(n), Pb(n) and Ni(II), no differences have been found in comparison with the selectivity of this extractant in organic solvents (36). The results of the numerical treatment indicate that the extraction of Pb(n) and Ni(II) can be explained by assuming the formation of PbL₂(HL₂ and NiL₂(HL)₂. However, the extraction of Ca(II) can be explained assuming the formation of two species CaL₂ and Ca(NO₃)L|The analysis of the separation factors indicates that Lewatit TP80784 allows a quantitative separation of Zn(II) from Cd(II), Ni(II) and Pb(II) with ApHso greater that 2 and quasi-quantitative separations (90-95%) from Cu(II)|The results obtained in the extraction of Zn(IT), Cu(H), Cd(II), Ni(II), and Pb(n) from water samples in column experiments are very satisfactory, and the sytem will be used on-line in a multicomponent spectrophotometric method for the monitoring of low levels of toxic metal ions in surface waters.     

淀粉基炭的制备及其对重金属离子的吸附性能

通过不完全炭化淀粉制备出无定形淀粉基炭材料,用X射线粉末衍射,TGA-DSC,红外光谱和比表面积测定对其进行了表征;研究了淀粉基炭对Cu2+,Pb2+,Cd2+,Zn2+的吸附性能,考察了淀粉基炭投加量、pH、温度和金属离子初始质量浓度对吸附效果的影响。金属离子的去除率随着淀粉基炭投加量的增加而上升,各种金属离子的最佳吸附pH分别为7.0(Cu2+),6.0(Pb2+),8.0(Cd2+),8.0(Zn2+)。温度越高越有利于吸附,吸附行为符合Langmuir等温吸附方程。     

Removal of heavy metals from municipal solid waste incineration (MSWI) fly ash by traditional and microwave acid extraction

BACKGROUND: Municipal solid waste incinerator (MSWI) fly ash is regarded as hazardous waste because it contains various toxic metals. A previous study has shown that fly ash can be detoxified by removal of heavy metals. In this work, the extractability of heavy metals from MSWI fly ash by traditional and microwave acid extraction were compared. RESULTS: A 2^{4 ? 1} fractional factorial experimental design was adopted using acid concentration, extraction time, temperature, and liquid/solid (L/S) ratio as the experimental factors for traditional extraction, and acid concentration, extraction time, liquid/solid (L/S) ratio and microwave power as the experimental factors for microwave extraction. The traditional extraction results show that L/S played an important role in Zn, Cd extraction while L/S ratio and extractant concentration were important for Pb extraction. However, no controlling parameter was determined for Cu and Cr extraction. For the microwave extraction, it was shown that L/S was important for Pb and Zn and extractant concentration was important for Pb, Zn and Cd. The time and the power were not significant for the extractability of heavy metals. CONCLUSION: Hydrochloric acid was an effective extractant. Microwave heating promoted extraction and shortened extraction time. Microwave acid extraction treatment is a potentially feasible method for the removal of heavy metals from MSWI fly ash. Copyright © 2010 Society of Chemical Industry     

巯基泥炭吸附重金属离子机理研究

从热力学、动力学及 XPS三个方面探讨了巯基泥炭对重金属离子的吸附机理。结果表明 :吸附过程以化学吸附为主。外表面、内表面对 Zn2 + 的吸附率分别为 1 6% ,84% ;Cu2 + 为 1 7% ,83% ;Pb2 +为 5 % ,95 % ;且吸附 Cd2 +完全由内扩散所控制     

衍生-超临界CO2萃取土壤样品中的金属离子

The method of using trifluoro acetyl acetone as chelating agent to extract Cu^2 , Hg^2 , Pb^2 ,Zn^2 , Cd^2 , Cr^3 from silica gel and soil sample by supercritical CO2 was investigated. The extracts were analyzed with the atomic absorption spectrophotometry method. The experimental results showed that at 20 MPa, 60℃ and with methanol as modifier, the metal ions mentioned above could be extracted efficiently. The recovery values for the simulated silica gel samples and soil sample were 91.0%-98. 2%and 77.8%-93.9%, respectively. This method was proved to be simple, quick and without pollution, which could be applied to the analysis of heavy metal ions in environmental samples.