Synthesis of a perfluorooctanoic acid molecularly imprinted polymer for the selective removal of perfluorooctanoic acid in an aqueous environment

Perfluorooctanoic acid (PFOA) contamination in the environment is a global problem. The aqueous phase is the main medium for PFOA because of its moderate solubility. Adsorption is a feasible way to remove PFOA because of its chemical and biological stability. In this study, a new type of molecularly imprinted polymer (MIP) for the selective adsorption of PFOA in aqueous solutions was synthesized by the precipitation polymerization method with PFOA as the template molecule after optimization. The adsorption kinetics and isotherms of the MIP adsorbent toward PFOA were studied, and the effects of the pH and cations on the adsorption were investigated with batch experiments. The results show that acrylamide (AAM) was the best functional monomer, and the optimal molar ratio of PFOA to AAM to ethylene glycol dimethacrylate (crosslinker) was 1:6:25. The optimized MIP adsorbent had a high affinity for PFOA, and the uptake percentage by the MIP adsorbent was 1.3–2.5 times that of the nonimprinted polymer (NIP) when PFOA existed alone. A maximum PFOA sorption capacity of 5.45 mg/g based on the Langmuir isotherm model was achieved with the MIP adsorbent. The MIP adsorbent exhibited a high selectivity for PFOA over competitive compounds (other perfluorinated alkyl carboxylic and sulfonic acids), whereas the NIP did not. Approximately 90% of the PFOA in the mixture was removed by the MIP adsorbent; this was 18 times that of the NIP. Moreover, the regenerability of the MIP adsorbent was confirmed in five sequential adsorption–desorption cycles without a significant reduction in the PFOA uptake. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43192.     

制酸熔硫系统乏汽及其凝结水回收装置的优化设计

针对大型硫黄制酸熔硫系统乏汽及其凝结水温度、压力特点,开发一种可操作的乏汽及其凝结水回收方法。介绍需要的设备和工艺流程,对回收难点提出针对性的解决方法,最大限度实现余热的回收再利用。该方法可显著提高余热回收利用量,减少原始新蒸汽的用量,降低熔硫系统生产成本,年产生经济效益900万元以上。     

MBR工艺在石化污水处理中的应用

随着国家对石化企业节水减排、污水回用的要求不断提高,MBR工艺在石化污水处理中的研究和工程应用越来越广泛。介绍了MBR工艺在已建石化污水处理装置提标改造和新建污水处理装置中的应用现状,对在应用中存在的问题进行了归纳梳理,提出了改进措施与建议,并结合MBR技术改进和材质升级,进一步展望了MBR技术在石化污水回用方面的发展趋势。     

氯碱废水实施分质处理及回收利用技术的应用探讨

结合实际论述了氯碱废水的特点;分析了氯碱废水分质处理及回收利用的总体思路;探究了氯碱废水实施分质处理及回收利用技术的应用策略,以期对充分利用氯碱资源及保护环境有所帮助。     

Application of titanium machining chips in welding consumables for wear-resistant hardfacing

Equipment of sugar cane plants and mineral extraction are submitted to severe abrasive wear conditions. Welded hardfacings are usually applied to repair this kind of damage, where commercial chromium/carbon-rich welding consumables have usually been employed. In the present work we investigated the microstructure of experimental hardfacings made by addition of residues (chips) collected from the machining of ASTM F67 (unalloyed Ti, grade 4) alloy. Mixtures with different carbide-formers (Cr/Nb ferro-alloys) were also tested. Two layers of ‘pure’ chips (Ti), chips plus Fe–Cr (Ti–Cr), and chips plus Fe–Nb (Ti–Nb) were applied on low-carbon steel specimens by the GTAW/TIG process. The microstructure of hardfacing layers was observed by optical and scanning electron microscopy (SEM) equipped with EDS microanalysis. The microstructural characterization has determined that carbide distributions change significantly with the chemical nature of the hardfacing. SEM observations coupled with EDS microanalysis have confirmed the formation of complex carbides within the metal weld, whose stoichiometry was determined by X-ray diffraction (XRD) analysis. Mixed carbides of MC type and some cementite have been found. As a result it was suggested that use of ASTM F67 chips as carbide formers for composition of welding consumables can contribute to improved wear resistance of hardfacings, if compared with traditional chromium-based hardfacings.     

Preparation of hardened tiles from waste phosphogypsum by a new intermittent pressing hydration

The solid waste phosphogypsum (PG), as the sole-raw material, was processed into hardened tiles with favorable mechanical strength by a novel intermittent pressing hydration process. First, the raw PG with dihydrate gypsum was dehydrated into semi-hydrate gypsum. The dehydrated PG was granulated with water, press-formed, and then immersed in water under intermittent pressing. Using the optimal granulation humidity of 35%, pressing pressure of 20 MPa, pressing frequency of once per 2 min and total times of 24, PG hardened tiles with bending strength of 18.9 MPa was obtained. It was revealed that the dehydrated PG was hydrated into the dense dihydrate gypsum crystals under the action of intermittent pressing, which contributed to the high mechanical strength of the tiles. The hardened tile has the potential to be a new-type wall material and its application may help to solve PG׳s environmental risk.     

资源循环利用对有色金属工业发展的影响

资源循环利用是把全社会已经使用过的物品、边角料、废弃物作为一种资源,经过技术处理重新服务于人类。而循环经济则是一种新的经济模型。资源循环利用对有色金属工业可持续发展意义重大,值得深入研究。本文对有色金属资源循环的必要性及资源循环型社会建立的条件进行了初步分析,以期引起人们的思考。     

试谈鸡西老煤炭工业基地煤竭城衰的重振对策

像所有的资源型城市一样,鸡西市也曾有过辉煌的发展历史,但近年来,鸡西市出现了“煤竭城衰”的现象。本文分析了这种现象产生的历史和原因,揭示了人与自然和谐发展的规律,并指出了解决这种现象的途径和办法。     

试谈鸡西老煤炭工业基地煤竭城衰的重振对策

像所有的资源型城市一样,鸡西市也曾有过辉煌的发展历史,但近年来,鸡西市出现了"煤竭城衰"的现象.本文分析了这种现象产生的历史和原因,揭示了人与自然和谐发展的规律,并指出了解决这种现象的途径和办法.