β-溴乙基溴代苯合成工艺研究

β-溴代苯乙烷在路易斯酸的催化作用下,与不同比例的溴素在苯环上发生取代反应,生成一系列不同溴含量的β-溴乙基溴代苯。考察了催化剂种类、反应温度、反应时间等因素的影响。结果表明,以铁粉和锑粉为催化剂,在30℃条件下滴加溴素反应4 h,滴加完成后在30~40℃条件下反应6 h,所得产品纯度大于98%、收率达98.7%。     

膜法海水提溴用PVDF中空纤维膜的研制

采用相转化法制备海水提溴用疏水性聚偏氟乙烯中空纤维膜,考察聚合物浓度、无机复合添加剂浓度、膜干燥方式及后处理方法对膜结构和性能的影响.结果表明,无机复合添加剂能有效提高膜机械性能,同时不影响膜疏水性;溶剂置换法不能完全避免膜收缩,从而直接影响膜孔结构和透气性能.物理后处理方法可显著提高膜透气性能,氮气通量为8.62 m3/(m2.h),孔隙率为63.31%,膜断裂强度可达到1.64 cN/Tex,膜断裂伸长率为79.10%.     

Evaluation and improvement of total organic bromine analysis with respect to reductive property of activated carbon

A collective parameter and a toxicity indicator for all the halogenated organic disinfection byproducts in a water sample is total organic halogen (TOX), which can be differentiated as total organic chlorine (TOCl), total organic bromine (TOBr) and total organic iodine. The TOX method involves concentration of organic halogens from water by adsorption onto activated carbon (AC). A previous study showed that a portion of TOCl can be reduced to chloride during the adsorption procedure, which can be minimized by ozonation of the AC. In this study, a portion of TOBr was sometimes found to be reduced by AC to bromide, and the reduction was generally less than that of corresponding TOCl. The results suggested that around 10% of brominated Suwannee River fulvic acid was reduced to bromide. However, some brominated amino compounds (especially glycylglycine, phenylalanine, and cytosine) were found to be more reactive with the AC. For the iodinated compounds studied, the reduction to iodide was not significant. The method for the TOBr measurement was improved by using ozonated AC when reduction occurred on the original AC. The improved method was also evaluated on treated wastewater and swimming pool water samples.     

离子液体中K_2CO_3/CH_3I直接催化合成碳酸二甲酯

利用高压间歇反应釜,考察了K2CO3/CH3I催化CO2与甲醇直接合成碳酸二甲酯(DMC)的反应规律,得到最佳的反应条件:反应温度363K、反应压力3.6M Pa、反应时间8h、m(甲醇)∶m(CH3I)∶m(K2CO3)=12∶2.3∶1。液相产物中DMC含量随K2CO3用量的增加几乎呈直线增加,因此可以在较低的反应压力下获得较高的DMC收率。另外,利用离子液体溴代1-乙基-3-甲基咪唑盐[Em im]B r对CO2的溶解特性,研究了离子液体[Em im]B r对K2CO3/CH3I催化CO2与甲醇直接合成DMC反应规律的影响。实验结果表明,在反应温度低于393K、反应压力高于4.0MPa的条件下,离子液体[Em im]B r可以加快反应速率,对反应具有一定的促进作用,但不能改变反应的最佳条件和整体规律性。甲醇、CH3I、[Em im]B r、K2CO3的最佳质量比为12∶2.3∶1.6∶1。     

Environmental issues related to end‐of‐life options of plastics containing brominated flame retardants

Bromine is used as the building block for some of the most effective flame retarding agents available to the plastics industry today. They are used to protect against the risk of accidental fires in a wide range of Electrical and Electronic Equipment (EEE). Brominated flame retardants (BFRs), as all flame retardants, act to decrease the risk of fire by increasing the fire resistance of the materials in which they are applied. There is a perception that BFRs affect adversely the end‐of‐life management of plastics through formation of Polybrominated Dibenzo Dioxins and Dibenzo Furans (PBDD/F). In fact, there exists a wide range of data and practical experience demonstrating that the end‐of‐life management of plastics containing BFRs is fully compliant with legislation setting the strictest limit values for PBDD/F and is fully compatible with an integrated waste management concept. Copyright © 2004 John Wiley & Sons, Ltd.     

Measurement of thermal stress in graphite intercalated with bromine

The thermal stress of graphite intercalated with bromine was found to increase from zero at about 100°C to about 1.3 MPa at 200°C. The effect was reversible with hysteresis. The thermal stress increase had a sharp temperature dependence due to its association with the exfoliation phase transition.Paper presented at the Ninth International Thermal Expansion Symposium, December 8–10, 1986, Pittsburgh, Pennsylvania, U.S.A.     

乙基香兰素合成工艺改进

采用氯化溴法合成3-溴-4-羟基苯甲醛,再通过乙氧基化合成乙基香兰素.对反应温度、反应时间、原料配比、溴化剂的滴加速度、溶剂等影响中间体产率的因素进行了研究.在溴化阶段用氯化溴代替溴素,用氯仿作溶剂,乙酸乙酯作助溶剂,使-溴化物的产率提高了9.4%;在乙氧基化步骤中用CuO作催化剂,用乙醇和DMF作反应溶剂,对原料配比和催化剂用量做了研究,使得最终产物乙基香兰素的产率达到82.5%.     

丙环唑废水治理技术研究

针对丙环唑废水COD浓度高、成分复杂、难生物降解等特点,首先采用氯气氧化方法回收废水中的溴,再采用铁碳微电解法处理废水。经过预处理后,废水中溴素的回收率为96%,废水的COD去除率达到90.5%;处理后废水的BOD5/COD由0.11提高到0.36。经好氧生化处理后出水符合国家一级排放标准(GB8978–1996)。     

D201大孔树脂吸附浓海水中溴的动力学特征

研究了D201大孔强碱性阴离子树脂吸附浓海水中溴的静态吸附动力学特征,考察了搅拌速度、树脂粒径、温度对吸附速率的影响,并用动边界模型对吸附过程进行描述。研究表明,D201树脂吸附溴的过程为颗粒扩散控制;搅拌速度、树脂粒径对吸附速率的影响不大：吸附速率随温度的升高而增大。计算了不同温度下的表观速率常数和表观活化能。     

活性炭的筛选及其吸附饮用水中低量溴化物的研究

本文通过研究星光K02活性炭、星光K04活性炭和太西活性炭等六种活性炭对饮用水中低量溴化物的吸附效率,筛选出了吸附效果最佳的太西活性炭。同时探讨了不同的活化方式、不同的吸附时间以及饮用水中不同的p H值对TAC(太西活性炭)吸附饮用水中低量溴化物(7.50μg/L)效率的影响。实验采用了蒸馏水浸泡和稀盐酸浸泡两种活化方式,用CO_2酸化的方式将饮用水中pH值分别调至6.00、7.00和7.68三个水平,在不同的时间点取样,用离子色谱仪检测其溴化物含量。不同条件下,TAC吸附溴化物效率不同。实验结果表明,用稀盐酸浸泡作为活化方式,同时将饮用水的p H值调至6.00,在实验开始后的两个小时内TAC吸附溴化物效果最佳,能达到85.35%,此时溴化物含量为1.10μg/L,即使在后续的臭氧灭菌阶段,溴离子全部被氧化成溴酸盐,溴酸盐的值会在5μg/L以内,远小于GB 5749-2006和GB 8537-2018中溴酸盐的规定限值(10μg/L),同时,TAC对饮用水中的常量元素钾钠钙镁、微量元素锶及偏硅酸等影响不大(小于10%)。因此,在实际生产中,可先将饮用水中p H值调至6.00,然后采用盐酸溶液预处理后的TAC对饮用水中低量溴离子进行去除。