Selective oxidation of benzyl alcohols to benzoic acid catalyzed by eco-friendly cobalt thioporphyrazine catalyst supported on silica-coated magnetic nanospheres

A novel magnetically recoverable thioporphyrazine catalyst (CoPz(S-Bu)8/SiO2@Fe3O4) was prepared by immobilization of the cobalt octkis(butylthio) porphyrazine complex (CoPz(S-Bu)8) on silica-coated magnetic nanospheres (SiO2@Fe3O4). The composite CoPz(S-Bu)8/SiO2@Fe3O4 appeared to be an active catalyst in the oxidation of benzyl alcohol in aqueous solution using hydrogen peroxide (H2O2) as oxidant under Xe-lamp irradiation, with 36.4% conversion of benzyl alcohol, about 99% selectivity for benzoic acid and turnover number (TON) of 61.7 at ambient temperature. The biomimetic catalyst CoPz(S-Bu)8 was supported on the magnetic carrier SiO2@Fe3O4 so as to suspend it in aqueous solution to react with substrates, utilizing its lipophilicity. Meanwhile the CoPz(S-Bu)8 can use its unique advantages to control the selectivity of photocatalytic oxidation without the substrate being subjected to deep oxidation. The influence of various reaction parameters on the conversion rate of benzyl alcohol and selectivity of benzoic acid was investigated in detail. Moreover, photocatalytic oxidation of substituted benzyl alcohols was obtained with high conversion and excellent selectivity, specifically conversion close to 70%, selectivity close to 100% and TON of 113.6 for para-position electron-donating groups. The selectivity and eco-friendliness of the biomimetic photocatalyst give it great potential for practical applications.     

聚酰胺复合纳滤膜的制备及除盐研究

以聚砜超滤膜为支撑膜,分别采用1,6-己二胺、邻苯二胺和哌嗪为水相功能单体,均苯三甲酰氯（TMC）为油相功能单体,通过界面聚合法制备了纳滤膜。通过过膜试验,比较了三种配方制得纳滤膜的水通量和脱盐效率;并对纳滤膜功能层聚哌嗪均苯三甲酰胺进行深入研究,探讨了哌嗪与TMC界面聚合反应的最佳胺氯比。实验结果表明,哌嗪与TMC界面聚合反应制得的纳滤膜性能优于其他两种配方,并且当两者的胺氯比约为10∶1时,所制得的复合膜具有最佳脱盐效果。     

树脂基固态胺吸附材料的选择性CO2吸附性能

基于简单的湿浸渍法将聚乙烯亚胺(PEI)有效负载到多孔树脂(HP20)中,制备获得树脂基固态胺吸附材料,并探究了PEI负载量(30%~60%)、吸附温度(30~90℃)和压力(2~100kPa)对材料CO₂吸附性能的影响.研究表明树脂基固态胺吸附材料的最佳PEI负载量为50%,过量的PEI会致使材料CO₂吸附容量和胺基利用效率的显著降低.所筛选的材料在较低或较高的CO₂分压范围内均能展现出优异的CO₂吸附性能,在30℃下的CO₂吸附容量达到3.06~3.78mmol/g,表明该材料在不同CO₂分压的多种碳捕集应用中均有着较好的适用性.此外,树脂基固态胺吸附材料的CO₂/CH₄和CO₂/N₂选择性在2~100kPa的压力范围内分别有262~5858和708~11551,在各类传统或新兴的固体吸附材料中处于较高水平.     

用苯甲醇精制残液制备苯甲醛

以苯甲醇精制残液为原料，在HNO3与Zn（NO3）2／硅胶作用下制备苯甲醛。在200mL原料中加入20mL CCl4，反应pH控制在2—3，温度98℃，采用80g 120目硅胶负载50g Zn（NO3）2催化剂，在此条件下苯甲醛的收率可达83．1％。该生产工艺简单，反应条件温和，自制Zn（NO3）2／硅胶催化性能优良。具有环保与经济双重价值。     

A COLORIMETRIC METHOD FOR THE DETERMINATION OF TRACE COPPER CONCENTRATIONS IN WATER1

Trace quantities of copper (II) ion can be found in natural water as waste products from industrial, mining, and agricultural operations. Because low concentrations of copper can be toxic to plant life, many workers have devised methods of analysis for this metal in water. These methods require expensive equipment and skilled technicians. The described study illustrates a simple method in which copper (II) ion is concentrated by a batch ion exchange technique and estimated colorimetrically after formation of the blue triethylenetetramine complex. Using the visible absorption peak of the complex at 600 nm it was possible to obtain accurate estimations of original copper concentrations in the range 0.5-3 ppm. Using the complex absorption peak at 260 nm in the ultra-violet region of the spectrum increased the sensitivity by a factor of twenty. Because of the dependence of the complex formation reaction on solution acidity it is possible to optimize conditions for the detection of copper (II) in the presence of other metal ions. This type of method, which could be extended to the analysis of other metal ions, could be performed by a relatively unskilled technician under field conditions.     

焦炉煤气的净化和有效利用途径

随着我国钢铁工业的发展，焦化行业进入到一个大发展时期。大量焦炉煤气的产生，为焦炉煤气的合理开发利用提出了新的课题。焦炉煤气的有效利用可产生巨大的经济效益，并且可避免环境污染和二次能源的浪费。     

醇类助溶剂去除砂土中多氯联苯作用机制

醇类助溶剂单一使用及复配表面活性剂使用去除砂土中多氯联苯(PCBs)的关键是增溶和降低界面张力.通过降低界面张力实验和振荡增溶实验分析了醇类助溶剂单一使用对多氯联苯界面张力的降低作用和增溶作用,以及醇类复配Triton X-100使用时醇对Triton X-100降低界面张力和增溶PCBs的影响.结果表明,醇-PCBs油的界面张力与醇浓度、醇含碳原子数均呈负相关,甲醇、乙醇、异丙醇的最佳解吸浓度分别为70%、55%、40%,最佳解吸效率达90%以上;Triton X-100-PCBs油界面张力与Triton X-100浓度呈负相关,Triton X-100浓度低于3 000 mg/L时复配10%乙醇、10%异丙醇比单一Triton X-100振荡洗脱效率低,Triton X-100浓度在3 000～7 500 mg/L时3组差异不大,Triton X-100浓度为10 000 mg/L时单一、10%乙醇、10%异丙醇TritonX-100溶液解吸效率分别为80.9%、90.36%、89.36%.表明醇类单一使用对降低界面张力与增溶均有很好的效果,但需要其体积分数达40%以上;醇类复配Triton X-100时醇的存在弱化了Triton X-100增溶和降低界面张力的作用,乙醇与异丙醇弱化作用差异性不大,当Triton X-100浓度高于3 000 mg/L时,弱化作用不显著.     

气相色谱法分析环境空气和废气中正丁醇

以纯净水吸收环境空气或工业废气中的正丁醇,用Rtx-WAX毛细管柱分离,氢火焰离子化检测器检测,吹扫捕集后进气相色谱仪测定。方法最低检出量浓度正丁醇0.005mg/m3,相对标准偏差在1%以下,加标回收率在85.8%～93.00%之间,方法安全环保,简单灵敏,分离度好,检出限低。     

一株耐酒精纤维素分解菌的分离鉴定及生长条件研究

木薯酒精糟因其低营养高含水量而难以利用和处理,目前对新鲜木薯酒精糟主要采用机械脱水及干燥的方法,但此类方法的经济成本和能耗都较高,很难形成产业化。该实验在木薯酒精糟中通过用刚果红培养基初筛和杜博氏培养基复筛得到一株耐酒精的纤维素分解菌,编为13号。经16S rRNA序列鉴定与链霉菌同源性达99%。其最适生长pH值为6.5,最适生长温度为40℃。对酒精有一定的耐受性,能在酒精浓度为6%的环境中生长,并且在酒精浓度为1%时对菌株生长影响不大。同时该菌能在40℃的温度条件下保持良好的生长态势,对适应废物堆肥发酵后期熟化产生有益次生代谢产物有利。所以利用此菌耐酒精、产纤维素酶且较耐高温等特性,对于处理含酒精的纤维素废物具有较好的应用前景。     

用于改善苯甲醇废水生化可降解性的氧化处理工艺

采用O3/Fenton组合工艺对苯甲醇模拟废水进行氧化处理,主要考察pH值,O3通入量,H2O2投加量,FeSO4加入量,反应时间对氧化效果的影响。比较了污染物苯甲醇在氧化过程中可能经历的特征分子作为污染物时废水的BOD5/COD值,确定顺丁烯二酸为最终氧化产物。结果表明:O3投加量为0.93 g/h,H2O2投加量为5 g/L,FeSO4加入量为1 g/L,pH为8,反应时间为60 min,在此条件下,顺丁烯二酸的质量分数达到42.19%。O3/Fenton组合工艺能够有效的将生化可降解性差的苯甲醇废水转化为可生化性较好有机废水,其中的特征污染物由苯甲醇转化为顺丁烯二酸,可生化指数大大提高。