Removal and recycle of heavy metals in sludge

［中文文摘］论述了利用离子交换技术循环使用柠檬酸去除污泥中重金属,并置换回收重金属的适宜工艺条件。经柠檬酸处理后,污泥中90%以上的重金属被去除;柠檬酸处理液中的重金属用离子交换法回收,考察了树脂种类、流速、操作方式等因素对离子交换、再生效果的影响;在适宜工艺条件下,重金属的交换率均为100%,而洗脱率均接近90%;柠檬酸及离子交换树脂循环使用,重金属也得到回收,降低了处理成本。［英文文摘］　Heavy metals in wastewater t reatment sludge were first ext racted by cit ric acid and subsequently re2 moved f rom the cit ric acid byion exchange. They were recovered f rom the ion exchange bed by dilute HCl and , final2 ly , were replaced in the spent HCl by Al to form valuable water t reatment coagulant and recycleable metals. The effects of resin types , flow rate and flow pattern on the IX t reatment and regeneration were determined. Using 0. 2 M citric acid at p H of 3. 0 , more than 90 % of the heavy metal content was ext racted in 24 hours ; the metal removed sludge could be used as a natural fertilizer. The least costly 732 cationic resin performed the best among the four cat2 ionic IX resins studied ; nearly 100 % of heavy metals in the cit ric acid feed were removed and that regeneration recov2 ered more than 90 % of those removed. The process employing cit ric acid for sludge ext raction , 732 cationic resin for removing the metal in the cit ric acid , 3 bed volumes of 5 % HCl for resin regeneration , and Al slices for replacing the recovered heavy metals in the spent HCl is a low cost method ( YMB ＄35/ ton dry sludge) for removal and recycle of heavy metals in the sludge

Research and development in the reactive systems of wet oxidation abroad

［中文文摘］简要介绍湿式氧化反应系统的应用历史、反应机理及动力学特征,以及该反应系统的设计及现有反应设备的特点、工业化中面临的难题等。重点介绍了国外主要的已工业化的湿式氧化反应系统,并针对不同反应系统在反应设备、操作条件、处理效果等方面的特点进行比较总结。在小结湿式氧化反应系统研究应用现状的基础上提出了今后研究开发的方向。［英文文摘］The history and the reactive mechanism and kinetic properties of wetoxidation processes were (introduced), and a general description of wet oxidation (processes) was given, including the features of reactors and the (design) of related reactive systems, practical problems, etc. By reviewing the commercial experiences of wet oxidation (processes) grouped as two types for further introduction, namely, non-catalytic wet oxidation process and catalytic wet oxidation process, several main commercial reaction systems abroad were focally introduced, in which the characteristics of reactors, operating conditions and treating efficiency of each type of reactive system were generalized and compared. The further research and development work were suggested

Electrocatalytic Oxidation of Glucose on Carbon Nanotube/Nanocrystalline TiO_2 Film Loaded Pt Complex Electrode

用电化学循环伏安法和计时电位法研究了葡萄糖在碳纳米管 /纳米TiO2 膜载Pt (CNT/nano TiO2 /Pt)复合电极上的电催化氧化 .结果表明 ,在碱性介质中CNT/nano TiO2 /Pt复合电极对葡萄糖的电氧化具有高催化活性 ,葡萄糖氧化峰电流密度高达 13mA/cm2 ,比铂电极上的增大一倍 ;复合电极性能稳定 ,抗中毒能力强 ,不易发生氧化振荡 ,是葡萄糖燃料电池和葡萄糖传感器的高活性催化电极 .Electrocatalytic oxidation of glucose on carbon nanotube/nanocrystalline TiO 2 film loaded Pt (CNT/nano-TiO 2/Pt) complex electrode was investigated by cyclic voltammetry and chronopotentiometry. The results indicated that CNT/nano-TiO 2/Pt complex electrode has high catalytic activity to the electrochemical oxidation of glucose in alkaline media, and the peak current density of oxidation of glucose is up to 13 mA/cm 2, which is one time higher than that on a platinum electrode. The complex electrode performance is stable, and it is strong resistant to poisoning and difficult to oxidize oscillatory. It is a highly catalytic electrode for using in glucose fuel cell and glucose sensor.安徽省自然科学基金 (No.0 0 0 4 531 7);; 安徽省高校科研基金(Nos.2 0 0 3kj1 4 1 ,2 0 0 4kj1 64zd)资助项

Study on mechanisms of silver biosorption by laminaria japonica

生物吸附金属作用机制的研究,有助于提高生物吸附剂的吸附能力。文章以前期优选出的对银具有较强吸附能力的海带为生物吸附材料,从静电吸附作用、离子交换作用、络合作用、沉淀作用几方面研究了其吸附Ag+过程可能存在的作用机制。结果表明:海带吸附银离子不依赖于静电吸附作用;吸附Ag+前后溶液中Na+、K+、Mg2+质量浓度的变化说明吸附过程中存在离子交换机制;海带表面的羧基、氨基和脂类基团经化学屏蔽后,对Ag+的吸附量明显下降,结合红外光谱分析结果,确定酰胺基CO—NH和离子化羧基COO-为海带与银离子发生络合作用的主要官能团;电镜结果表明海带在吸附过程中可以和Ag+形成沉淀沉积在细胞表面。The study on mechanisms of metal biosorption is helpful to improve the biosorption ability of organism.Mechanisms of silver biosorption by Laminaria japonica were discussed from several aspects such as electrostatic(adsorption,) ion exchange,complexation and deposition.The results show that silver biosorption by Laminaria(japonica) doesn′t depend on electrostatic adsorption,while ion exchange is responsible for biosorption because of(increase) of the mass concentration of Na~+,K~+,Mg~(2+) in solution before and after biosorption.Adsorptive capacity of Ag~+ distinctly decreases after functional groups such as carboxyl,amino and lipid groups in Laminaria japonica cell wall are chemically modified respectively.Combined with FTIR spectra,carboxyl and amino groups are(confirmed) to be the main active groups which can combine with silver ion.Precipitation can take place on the cell wall of Laminaria japonica through SEM characterization.国家自然科学基金资助项目(20376067

Effect of Ni~(2+) and Sn~(2+) Modified SO_4~(2-)/ZrO_2 Solid Super-Acid Catalysts on Visbreaking of Heavy Petroleum Oil

稠油黏度高的特性使其开采难度较大。为降低胜利油田稠油的黏度,制备了金属离子(Ni2+和Sn2+)改性的SO42-/ZrO2固体超强酸催化剂,考察了这两种催化剂对稠油的降黏性能。实验结果表明,Ni2+和Sn2+改性的SO24-/ZrO2固体超强酸催化剂能在较低的温度下催化稠油降黏,在反应温度240℃、压力3~4MPa、反应时间24h、稠油与催化剂质量比100∶0.05的条件下,稠油的黏度由0.319Pa.s分别降至0.135Pa.s和0.163Pa.s,降黏率达57.7%和48.9%。反应后,稠油中的饱和烃含量增加,芳烃、胶质和沥青质含量减少,杂原子S和N的含量降低。同时发现,水的存在对稠油降黏不利。SO2-4/ZrO2 solid super-acid catalysts(SZ) separately doped with Ni2+ and Sn2+(Ni2+/SZ,Sn2+/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field.The visbreaking reactions were carried out under conditions of 240 ℃,3-4 MPa,mass ratio of heavy petroleum oil to catalyst 100 ∶0.05 and reaction time 24 h.The effect of water content on viscosity change of heavy petroleum oil was also investigated.Both the catalysts can promote thermolysis of heavy petroleum oil,and make the viscosity dropping from 0.319 Pa·s to 0.135 Pa·s(Ni2+/SZ) and 0.163 Pa·s(Sn2+/SZ),respectively.The visbreaking rates are 57.7% and 48.9% correspondingly.After reactions,content of saturated hydrocarbons increases and contents of aromatics,resin and asphaltene decrease.At the same time,sulfur and nitrogen contents in heavy petroleum oil also reduce.The presence of water is disadvantageous to visbreaking of heavy petroleum oil.国家"973"计划项目(2004CB217805

Preparation of Au nanowires based on synergistic action of Pichia pastoris cells and surfactant

在毕赤酵母-十六烷基三甲基溴化铵(CTAb)的协同作用下利用抗坏血酸(AA)还原氯金酸(HAu Cl4)制备Au纳米线,采用SEM、TEM、HrTEM及SAEd等手段对Au产物进行表征,结果表明产物为带有分支结构的Au纳米线,纳米线在分叉处的晶型是连续的,具有多晶结构的特征。研究发现,菌体-HAu Cl4的相互作用对于后续纳米线的生成过程至关重要,部分Au(Ⅲ)可吸附在菌体表面并被还原为很小的Au(0),在AA加入后纳米线的生成过程中起到了晶种的作用。菌体-HAu Cl4作用时间过长会导致菌体表面生成的Au(0)趋于稳定,不利于进一步生长为Au纳米线。菌体-表面活性剂的协同作用导致分支结构的多晶Au纳米线的生成。Au nanowires(Au NWs) were obtained by the reduction of HAu Cl4 with ascorbic acid(AA) under the synergistic action between microorganism(Pichia pastoris cells, PPCs) and hexadecyltrimethylammonium bromides(CTAB).SEM, TEM, HRTEM and SEAD were used to characterize the shape and structure feature of the Au nanoproducts.The results showed the Au NWs were hierarchically branched polycrystal and the interfaces of the branched positions were continuous in lattice.The interaction process between the microorganism and CTAB was researched and it was found that Au(0) could be formed on the PPCs surface, which acted as the seeds for the formation of Au NWs after AA addtion.Without the interaction process between the microorganism and CTAB, the Au nanoparticles instead of nanowires were acquired.Too long time adsorption between PPCs and HAu Cl4 led to stable Au(0) on the microorganism surface, which was also unfavorable for the subsequent growth of Au NWs.The synergistic action between microorganism and CTAB resulted in the formation of Au NWs with hierarchically branched polycrystalline structure.国家自然科学基金项目(21406186)~

Study on fluorometric determination of hydrogen peroxide catalyzed by iron(III)-tetrasulfonato-phthalocyanine with thiamine hydrochloride as a substrate

Iron(III)-tetrasulfonatophthalocyanine(FeTSPc) has been used as a mimetic enzyme in the determination of hydrogen peroxide with thiamine hydrochloride as a fluorogenic substrate. The determinations were carried out in both acidic and basic environments, with different limits of detection and linear ranges. In acidic condition, the linear calibration graph was obtained from 5.0x10(-8) mol/L to 8.0x10(-6) mol/L, with a detection limit of 2.1x10(-8) mol/L H2O2 when Na2HPO4-citric buffer solution (pH 2.8) was used as the reaction medium. It was also found that using one of the three polybasic carboxylic acids such as citric acid, tartaric acid and malonic acid as the catalytic reaction medium can lead to particularly sensitive systems, permitting a detection limit as low as 3.5x10(-9) mol/L H2O2; whereas in basic reaction medium (Na2CO3-NaHCO3 buffer solution, pH = 10.0), the linear range of the calibration graph was from 5.0x10(-8) mol/L to 2.0x10(6) mol/L H2O2 with a detection limit of 1.4x10(-8) mol/L. The applicability of the method to the determination of glucose in human serum was demonstrated by investigating the recovery of the known glucose added to human serum

Plant-mediated synthesis of silver nanoparticles and application in antibacterial fabric

纳米银是以纳米技术为基础研制而成的新型抗菌产品,由于量子效应和尺寸效应具有普通银系抗菌剂无法比拟的抗菌效果。本研究以黄芩、丁香、洋浦桃、芳樟4种植物质提取液制备银纳米颗粒,并借助于uV-VIS、TEM以及Xrd对产物进行表征,结果表明增加植物质提取液浓度或增大nA OH加入量,均有利于制得粒径较小的银纳米颗粒。SEM图片表明采用浸渍法可将所得纳米银颗粒负载于纯棉织物上,通过考察浸渍时间、温度、浴比对织物上载银量的影响,确定较优的浸渍条件为时间30 H,温度55℃,浴比为1:25。分别考察了银纳米颗粒粒径和植物质种类对所得载银织物抗菌性能的影响,发现负载到织物上的纳米银粒径越小,织物抑菌效果越好;利用本身具有抑菌效果的黄芩、丁香来制备银纳米颗粒,有利于增强所得载银织物的整体抗菌性能;4种植物质中以黄芩制得的载银织物抗菌效果最优,对金黄色葡萄球菌、大肠杆菌等实验菌株均有强烈的抑制作用。Nano silver, based on the nanoscience and nanotechnology, exhibits excellent antibacterial ability due to the quantum effect and size effect.In this work, the plant-mediated synthesis of silver nanoparticles(Ag NPs) was reported from four plants, including Scutellaria baicalensis, Syzygium aromaticum, Syzygium samarangense and Cinnamomum camphora.The as-synthesized Ag NPs were characterized by UV-Vis, TEM and XRD techniques.The results indicated that the Ag NPs tended to be smaller with the increase of biomass concentration or Na OH adding amounts.SEM images verified that the Ag NPs can be loaded onto cotton fabric through impregnation, and the optimal conditions were time of 30 h, temperature of 55℃ and liquor ratio of 1:25.Furthermore, the effects of Ag NPs size and plant species on the antibacterial ability of the resulting Ag-coated fabrics were investigated, respectively.Ag NPs loaded on the fabrics with smaller size displaied superior antibacterial activity against Escherichia coli.Moreover, Ag-coated fabrics prepared from Scutellaria baicalensis and Syzygium aromaticum extracts, which possessed own antibacterial ability, showed the cooperative antibacterial effect between biomass and nano-silver.The as-prepared fabric by the extract of Scutellaria baicalensis exhibited the best antibacterial ability with high inhibition ratio against various bacteria such as Staphylococcus aureus and Escherichia coli.国家自然科学基金项目(21206140); 厦门市科技计划项目(3502Z20133006)~