碱熔法回收废催化剂中的钴、钼和铝

采用碱熔法从废钴钼催化剂中回收钴、钼和铝。该方法的工艺过程为 :将废催化剂与纯碱按质量比 1∶1 8混合 ,在焙烧温度 90 0℃条件下 ,焙烧 2h ;用 2倍于熔块的沸水浸取30min ;用稀硫酸调浸取液 pH至 6 ,浸取液中的铝形成氢氧化铝被回收 ;然后除盐并回收钼酸钠 ;使酸浸黑渣中的钴形成氢氧化钴并脱水氧化成为氧化钴。用该工艺回收铝、钼和钴 ,其回收率可达 95 %以上 ,回收产品的纯度可达 97%以上。     

不同酸碱度土壤阳离子交换量的测定研究

为了能够快速准确测定不同酸碱度土壤中的阳离子交换量,弥补现行标准方法的不足,对三氯化六氨合钴浸提-分光光度法中的土壤称样量、pH、浸提时间、浸提温度和离心时间等条件进行了优化。优化后的方法检出限为0.43 cmol^+/kg,测定下限为1.72 cmol^+/kg,方法实验室内精密度为0.2%~1.8%,适用于大批量土壤样品中阳离子交换量的测定。     

5-氯-2-(吡啶偶氮)-1,3-二氨基苯分光光度法测定水质钴

采用5-氯-2-(吡啶偶氮)-1,3-二氨基苯分光光度法测定水质钴。对分析方法的样品前处理、样品保存、样品分析条件、干扰消除、检出限及测定范围、实际样品测定进行了深入研究和技术改进。水样经消解后测定的方法检出限为0.009 mg/L,经富集后测定的方法检出限为4×10-4mg/L,干扰消除实验的回收率为96%~101%,地表水、地下水、生活污水及工业废水等4种类型水样的加标回收率为92%~103%。     

Concentration of some heavy metals in organically grown primitive,old and modern wheat genotypes: Implications for human health

The concentration of six HMs (Cd, Cr, Co, Pb, Hg and Ni) was analysed in 321 organically grown winter and spring wheat genotypes from six genotype groups, i.e. selections, old landraces, primitive wheat, spelt, old cultivars and cultivars. Also the potential risk of individual toxic HM to human health was estimated by using the Hazard Quotient (HQ). Significantly the lowest grain concentration of Cd was found in primitive wheat as compared to all other investigated genotype groups. Intake of HM by consumption of whole wheat grain was not found to pose a health risk to human for any of the investigated genotype groups. The bio-concentration factor of Cd for the different genotype groups indicated a lower ability to accumulate Cd for primitive wheat as compared to other genotype groups. The primitive wheat was found the most promising and might be of interest in future wheat breeding programs to develop wheat genotypes with low HMs concentration in the grain.     

废高磁合金钢中钴、镍的分离和利用

用硫酸、盐酸和硝酸溶解废高磁合金钢、并将Fe^2 氧化为Fe^3 。先用黄铁矾法除去大部分铁,用尿素除去少量的铁及铝、钛、铜;最后在NH3－NH4Cl体系中分离钴、镍,并制成相应的盐。钴、镍的回收率分别国81．5％、89．7％。     

金/钴氢氧化物膜修饰玻碳电极同时测定邻苯二酚和对苯二酚

文章将纳米金与钴氢氧化物膜的催化作用有效结合,制备了GNPs/CoOOH复合修饰电极,该修饰电极在碱性条件下对邻苯二酚和对苯二酚具有较强的电催化活性。考察了支持电解质酸度及纳米金沉积时间对邻苯二酚和对苯二酚电化学响应的影响,选取0.1 mol/L PBS(pH 10.0)作为支持电解质,纳米金的最佳沉积时间为4 min。在优化的实验条件下,利用差示脉冲伏安法(DPV)对邻苯二酚和对苯二酚进行选择性检测:当两者浓度同时改变时,对苯二酚和邻苯二酚的氧化峰电流与其浓度分别在7~100μmol/L和6~100μmol/L范围内呈良好的线性关系,对应的检出限分别为0.9、0.8μmol/L(S/N=3)。该复合修饰电极具有较好的重现性、稳定性及较强的抗干扰能力。     

葡萄藻生物膜贴壁培养处理含钴工业废水与烃类生产的耦合

工业废水污染日趋严重,水体中重金属钴污染因难处理、高危害等问题成为废水净化的关键.传统治理重金属工业废水的方法难以应用.为寻求处理工业废水"绿色生态"可行性路径,本文以葡萄藻Botryococcus braunii SAG 807-1为研究对象,应用贴壁培养技术对含钴工业废水进行处理研究.结果表明,葡萄藻贴壁培养可处理工业废水,4.5 mg·L~(-1)Co~(2+)对葡萄藻生长影响不大,却可以促进长链烃类的合成,提高烃产量.葡萄藻贴壁培养去除Co2+的能力为1 473.9μmol·g~(-1),远高于报道的微藻P.littoralis.本研究为绿色高能燃料烃类的生产与工业废水处理耦合提供理论基础.     

镍钴转运酶NiCoT基因的克隆表达及基因工程菌对镍离子的富集

利用PCR技术从Staphylococcus aureus/ ATCC6538基因组中扩增出大小为1?053 bp的镍钴转运酶基因NiCoT gene,将其连接到pET-3c载体上构建重组质粒,并转化至E.coli BL21.筛选阳性菌并经酶切分析和PCR扩增双重鉴定.核苷酸序列测定及分析结果与GenBank中报道的同类基因相似性高达97%以上,表明其具有正确的NiCoT基因核苷酸序列.重组菌的SDS-PAGE结果图谱中,在相对分子量为39?000附近有特异性蛋白条带,大小符合预测值,表明NiCoT基因在E.coli BL21中成功表达.基因工程菌在IPTG用量为1.00 mmol·L^-1,诱导时间为4 h的条件下培养对镍离子的富集能力最高.在不同镍离子浓度时,基因工程菌对溶液中Ni²⁺的平衡富集量为11.33 mg·g^-1,与原始宿主菌相比提高了3倍.对基因工程菌吸附镍和钴的实验表明,Staphylococcus aureus ATCC6538的NiCoT对镍具有较高的特异性和富集容量,属于第Ⅲ类镍钴转运酶.     

Kinetics and thermodynamics studies of cobalt,strontium and caesium sorption on marble from aqueous solution

Adsorption onto solid phases plays an important role in the transport of radionuclides and contaminants in the environment. Radionuclides in radioactive waste have been considered to be hazardous pollutants, and their migration with groundwater is strongly affected by sorption on the geologic media. Therefore, the knowledge of radionuclide sorption is of great importance in the management of radioactive wastes. A series of batch sorption experiments were conducted separately to investigate sorption and transport behaviour of cobalt, strontium and caesium on and through marble. Batch-mode kinetic and equilibrium studies have been carried out at different temperatures. Sorption experimental data were analysed by kinetic and isotherm models. Based on the results obtained, it can be concluded that the marble is an economic and efficient retaining material for environmental hazardous migration and/or leakage of some radionuclides. Therefore, this study could be used as a starting point to establish and consider that rock as a reactive barrier around the disposal facilities at the nuclear activity centres.     

A potentiometric cobalt-based phosphate sensor based on screen-printing technology

A potentiometric cobalt-based screen-pritning sensor was fabricated by electroplating cobalt on the surface of a screen-printing electrode as the sensitive layer for the determination of dihydrogenphosphate （H2PO4） in wastewater samples. The electrochemical performance of this sensor was fully examined to determine its detection calibration, detection limit, response time, selectivity, and interference with pH, various ions, and dissolved oxygen （DO）. The cobalt-based phosphate sensor showed a phosphate-selective potential response in the range of 10 5mol·L^-1 to 10^-1 mol^-1, yielding a detection limit of 3.16 × 10μmol·L^l and a slope of -37.51 mV·decade＇ in an acidic solution （pH 4.0） of H2PO4-. DO and pH were found to interfere with sensor responses to phosphate. Ultimately, the performance of the sensor was validated for detecting wastewater samples from the Xiaojiahe Waste- water Treatment Plant against the standard speetrophotometric methods for HzPO4 analysis. The discrepancy between the two methods was generally ＋5% （relative standard deviation）. Aside from its high selectivity, sensitivity, and stability, which are comparable with conventional bulk Co-wire sensors, the proposed phosphate sensor presents many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices, such as flow injectors.