超重力法制备CNT负载MnFe2O4纳米材料及吸附Pb(II)应用

为改善MnFe2O4纳米颗粒在实际应用中的团聚问题，结合多壁碳纳米管(CNT)原位负载，提出超重力法制备CNT负载MnFe2O4纳米材料(MnFe2O4/CNT)。以典型的重金属污染Pb(II)作为研究对象，对其吸附性能进行研究。首先考察了MnFe2O4负载量对Pb(II)吸附容量的影响，确定最佳MnFe2O4负载量为83.3wt%。采用XRD, SEM, N2吸附-脱附比表面分析仪和VSM对最佳MnFe2O4负载量条件下的MnFe2O4/CNT进行表征。MnFe2O4/CNT展现出优异的磁性，其饱和磁化强度为35.85 emu/g，因而可应用于水体中污染物的磁性分离。吸附实验结果表明在初始Pb(II)浓度300 mg/L和溶液pH=6的条件下，Pb(II)在MnFe2O4/CNT上180 min达到吸附平衡，吸附平衡容量为80.7 mg/g，远高于单独的CNT (28.4 mg/g)。动力学研究表明Pb(II)在MnFe2O4/CNT上的吸附符合Elvoch动力学模型，说明吸附机理中存在化学吸附。Freundlich等温线模型能够很好地描述Pb(II)在MnFe2O4/CNT上的吸附过程，其代表发生在非均匀表面的多分子层吸附。另外，吸附等温线实验中获得的MnFe2O4/CNT最大吸附容量为106.2 mg/g，展现出了对重金属Pb(II)优异的吸附性能，在去除溶液中重金属中具有较大的应用潜力。根据X射线光电子能谱分析，表明吸附机理涉及到Pb(II)与MnFe2O4表面羟基的络合。     

磺化腐植酸-壳聚糖交联吸附剂制备及对Pb(Ⅱ)吸附性能

以腐植酸和壳聚糖为原料,通过固相交联法制备磺化腐植酸-壳聚糖交联共聚物（SHACTS）,对Pb (Ⅱ)的吸附性能进行研究,考察吸附过程中pH值、吸附时间、SHA-CTS投加量对水中Pb(Ⅱ)的去除率和吸附量的影响,采用扫描电子显微镜（SEM）和红外光谱（FT-IR）对SHA-CTS进行表征。结果表明,25℃时,在初始浓度为20 mg/L、pH值为5的50 mL Pb(Ⅱ)溶液中加入SHA-CTS 50 mg,SHA-CTS对Pb(Ⅱ)的去除率达到100%。SHA-CTS对Pb(Ⅱ)吸附符合准二级动力学模型,吸附等温线符合Freundlich模型,属于以化学吸附为主的多分子层吸附,最大吸附量为90.09 mg/g。     

聚乙烯亚胺改性磁性膨润土对Pb2 和Cu2 的吸附性能

在磁性膨润土(MBent)表面接枝聚乙烯亚胺(PEI)制备了聚乙烯亚胺改性磁性膨润土(PEI/KH560/MBent),采用FTIR、VSM、XRD、TGA、EA、SEM和EDS对其进行了表征,考察了其对水溶液中Pb2+和Cu2+的吸附性能.结果表明,聚乙烯亚胺已成功接枝于磁性膨润土表面,并有效提高了其对Pb2+和Cu2+的吸附量;溶液初始pH对吸附量影响较大,随着pH的增大,吸附量增加.在pH=5,溶液初始质量浓度为300 mg/L,PEI/KH560/MBent对Pb2+和Cu2+吸附量分别为96.21和61.08 mg/g;吸附过程符合准二级动力学模型,吸附行为符合Langmuir吸附等温模型.热力学研究表明,吸附为自发吸热过程.经过5次循环利用后,其吸附容量仍保持初始的60％以上,表明PEI/KH560/MBent具有一定的重复利用性.     

磁性水热炭对重金属离子铅的吸附性能研究

研究磁性水热炭对Pb⁽²⁺⁾的吸附,采用原子吸收光谱仪测定Pb(2+)的吸附,采用原子吸收光谱仪测定Pb⁽²⁺⁾的浓度,控制单因素变量法研究了投加量、pH、时间和初始离子浓度等对Pb(2+)的浓度,控制单因素变量法研究了投加量、pH、时间和初始离子浓度等对Pb⁽²⁺⁾的吸附研究。结果表明,在初始离子浓度50 mg/L,投加量为0.05 g、pH 5.0,温度30℃以及吸附时间2 h时,吸附去除率达到93.88%,吸附量为46.94 mg/g。用准二级动力学方程模拟实验数据,相关系数可达到0.999 9,吸附过程可用Langmuir吸附等温模型来描述,说明磁性水热炭对Pb(2+)的吸附研究。结果表明,在初始离子浓度50 mg/L,投加量为0.05 g、pH 5.0,温度30℃以及吸附时间2 h时,吸附去除率达到93.88%,吸附量为46.94 mg/g。用准二级动力学方程模拟实验数据,相关系数可达到0.999 9,吸附过程可用Langmuir吸附等温模型来描述,说明磁性水热炭对Pb⁽²⁺⁾的吸附过程为单分子层的化学吸附。     

精氨酸修饰磁性海泡石对Pb~(2+)的吸附研究

通过对天然海泡石磁化和精氨酸表面修饰,制备了一种氨基酸修饰的磁性海泡石(L-Arg-MSEP)。采用SEM、VSM、XRD、FTIR和BET方法对其结构进行表征和分析,对比在不同pH值、吸附剂投加量、时间、温度和初始浓度条件下,海泡石及其复合改性海泡石对水中Pb⁽²⁺⁾的吸附效率。结果表明,L-Arg-MSEP不仅具有超顺磁性,而且成功引入氨基,有利于提高其对Pb(2+)的吸附效率。结果表明,L-Arg-MSEP不仅具有超顺磁性,而且成功引入氨基,有利于提高其对Pb⁽²⁺⁾的吸附性能;在30℃,溶液pH为5.0,Pb(2+)的吸附性能;在30℃,溶液pH为5.0,Pb⁽²⁺⁾的初始浓度为200 mg/L,吸附剂投加量为2 g/L的最佳吸附实验条件下,L-Arg-MSEP对Pb(2+)的初始浓度为200 mg/L,吸附剂投加量为2 g/L的最佳吸附实验条件下,L-Arg-MSEP对Pb⁽²⁺⁾的最大吸附量为130.59 mg/g;L-Arg-MSEP对Pb(2+)的最大吸附量为130.59 mg/g;L-Arg-MSEP对Pb⁽²⁺⁾的吸附更符合准二级动力学模型和Langmuir等温吸附模型。吸附过程为自发的放热过程。     

羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)、Cd(Ⅱ)吸附性能研究

以CO2为活化剂制备羊骨炭,在不同溶液pH、初始浓度、活性炭投加量等条件下,通过动态吸附试验考察羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)和Cd(Ⅱ)的吸附规律,并用Langmuir和Freundlich吸附等温模型对其吸附性能进行了分析。结果表明,当羊骨炭对Pb(Ⅱ)、Cr(Ⅵ)和Cd(Ⅱ)的最佳吸附量分别为:4.2 mg/g、0.07 mg/g和2.7 mg/g时,吸附液的pH值Pb(Ⅱ)、Cd(Ⅱ)为7～8、Cr(Ⅵ)为酸性pH<6;羊骨炭的投加量分别为:0.2、0.7、0.03 g;最佳初始浓度分别为:60 mg/L、15 mg/L、30 mg/L。羊骨炭对3种离子的吸附行为基本符合Langmuir吸附等温模型和Freundlich吸附等温模型,计算得四种离子的最大吸附量分别为:4.854、1.247、0.402 mg/g。     

氧化铝改性污泥生物炭粒制备及其对Pb(Ⅱ)的吸附特性

为拓展城市剩余污泥资源化利用途径，本文以剩余污泥球粒为原料在高温限氧条件下制备污泥生物炭粒（SBC），同时以氢氧化铝溶胶为前体浸渍污泥球粒后在500℃下热解获得氧化铝改性污泥生物炭粒（SBC-Al）。使用BET、XRD、FTIR和SEM对生物炭粒进行了表征，并研究了生物炭粒改性前后对Pb(Ⅱ)的吸附特征及效果。结果表明：SBC-Al比表面积和总孔容分别达到83.266m²/g和0.158cm³/g，相比于SBC分别增大了142.42%和167.80%；XRD显示氢氧化铝溶胶浸渍使SBC-Al表面负载了γ-Al₂O₃粒子，FTIR红外谱图说明氧化铝改性可能会增加炭粒表面官能团数量，同时SEM显示出SBC-Al表面相较于SBC具有更多的层片状结构，从而增加生物炭粒的吸附性能。Pb(Ⅱ)的吸附动力学符合二级动力学方程和Elovich方程，同时用二阶段颗粒内扩散模型可以较好地拟合。吸附等温线以Freundlich模型为主，且SBC和SBC-Al对低浓度（＜50mg/L）Pb(Ⅱ)的去除率均较高，分别在95%和99%以上，实测最大吸附量可分别达626.73mg/g和663.97mg/g，但SBC-Al提高了对更高浓度（50～100mg/L）Pb(Ⅱ)的去除率。热力学计算数据表明吸附过程为吸热反应；脱附解吸试验说明，生物炭粒具有良好的循环再生利用性能。     

含磺酸钠聚合物微凝胶的制备及对Cu(II)和Pb(II)的吸附

采用回流-沉淀聚合制备了含磺酸钠聚合物微凝胶(SSPMg),通过扫描电子显微镜(SEM)、比表面及孔隙度分析(BET)、傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)等对其结构性能和化学组成进行了表征,并考察了SSPMg对Cu(II)和Pb(II)的吸附性能。结果表明,对苯乙烯磺酸钠占共聚单体总质量17.5%的微凝胶(SSPMg-4)在pH值=5时吸附效果最佳;吸附过程更符合准二级动力学和Langmuir等温吸附模型,以单分子层的化学吸附为主,包括络合、离子交换和静电吸附作用;吸附过程ΔG小于0、ΔH大于0,表现为常温下的自发吸热过程。298.15 K时,SSPMg-4对Cu(II)和Pb(II)的Langmuir理论最大吸附量分别达523.56 mg/g和568.18 mg/g。经过6次循环使用后,SSPMg-4对Cu(II)和Pb(II)的去除率保持在初始去除率的92%以上。     

A.ferrooxidans次生矿物对水中Pb(Ⅱ)吸附性能的研究

通过Acidithiobacillus ferrooxidans(简称A.f菌)代谢制备次生高铁矿物,研究矿物用量、吸附时间和初始Pb2+浓度对吸附性能的影响,借助等温吸附技术探讨该矿物对Pb2+的吸附平衡特征。结果表明,在Pb2+初始浓度为15 mg/L、体积为50 m L、温度30℃、pH为3.0、吸附时间为60 min、矿物用量为10 g/L的条件下,次生矿物对Pb2+的静态吸附率达90.67%,符合Langmuir静态吸附模型,最大吸附量达2.02 mg/g,吸附平衡常数(KL)为9.27 L/mg。     

响应面优化CMODE吸附剂的制备及其性能研究

为优化提升天然硅藻土对水体中重金属的吸附性能，采用“煅烧-钙化-柱撑”三步法对天然硅藻土进行纯化改性，合成制备硅藻土基改性吸附剂（CMODE）。利用响应面法的Box-Behnken设计优化CMODE吸附剂的制备条件，结果表明对CMODE制备影响顺序为：煅烧温度（X1）>Ca2+浓度（X2）>OH-/Al3+比（X3），且在煅烧温度350℃、Ca2+浓度5%、柱化液OH-/Al3+比2.2的优化条件下，CMODE对Pb(II)吸附去除率预测值可达93.45%，验证试验得到Pb(II)去除率为92.83%，与模型预测值的偏差仅为0.62%，说明实验值与模型预测值之间拟合良好，回归拟合得到的二次多项式模型能够有效预测CMODE吸附性能。CMODE对Pb(II)的吸附过程与二级动力学模型和Langmuir等温吸附模型拟合良好，表明CMODE对Pb(II)的吸附为单分子层化学吸附，且CMODE对Pb(II)的吸附作用以静电吸引、离子交换和表面络合为主。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。