电子束辐照技术在环境保护中的应用

电子束辐照降解技术作为辐照技术的一个分支,近年来获得了快速发展,在环境保护中的应用日益广泛。概述了电子束辐照降解技术在处理废气、废水以及固体废弃物等方面的研究应用,指出了环境保护中电子束辐照技术所存在的问题,并展望了其应用前景。     

BH无氰浸锌液的性能及其在高硅铝合金上的应用

开发了一种用于高硅铝合金预处理的环保BH无氰浸锌液。对比研究了BH无氰浸锌、市售无氰浸锌和有氰浸锌所得浸锌层的结合力、组成、合金化状态和碱铜覆盖情况等性能。结果表明,BH无氰浸锌液的各种性能均明显优于市售无氰浸锌液,且接近于有氰浸锌液,有望取代有氰浸锌液。介绍了BH无氰浸锌工艺在实际生产中的应用和优势。     

高硅铝合金无氰浸锌的应用及故障解决

BH无氰浸锌液是新开发的应用于高硅铝合金预处理的产品,其各方面性能与含氰浸锌接近而优于市售无氰浸锌产品。本文通过扫描电镜照片比较了纯铝和高硅铝合金经BH无氰浸锌、市售主流无氰浸锌及有氰浸锌处理后的表面形貌,发现无论是纯铝还是高硅铝合金,采用市售无氰浸锌液处理后的表面覆盖程度均较差,而BH无氰浸锌液和有氰浸锌液所得浸锌层的覆盖程度接近,介绍了BH无氰浸锌在工业上的应用情况及其在应用过程中产生的问题,如基体与铜层、挂具点附近、孔位、低位、凹槽以及铜与银层之间的起泡现象,分析了产生问题的原因,并提出了相应的解决办法,如:以水性笔代替油性笔标记镀件,每次电镀后对挂具进行退镀和将除垢温度控制在40°C以下,浸锌前增加热水清洗且清洗后甩净孔内液体,调整或更换碱铜槽,调整浸锌槽并加入配位剂,预镀银时工件带电入槽或调整镀银槽。     

电子束辐照降解氯苯类废水

氯苯类是重要的有机污染物,采用常规处理方法难以降解。利用束流为1mA、电子束能量为1 5MeV的高能电子束辐照处理氯苯、邻,间,对 二氯苯、1,2,4 三氯苯5种氯苯类化合物的模拟废水。辐照剂量分别为35、70、105、140、210kGy。实验表明,电子束能够降解氯苯类废水,邻二氯苯、间二氯苯、对二氯苯、氯苯降解率为50%时所需剂量分别为:38、35、46、206kGy。相同剂量下各化合物的降解率顺序为:氯苯<二氯苯<1,2,4 三氯苯,辐照降解过程中氯离子的质量浓度增加,辐照后溶液呈强酸性,pH=2～3。     

电子束辐照降解土霉素制药废水COD技术研究

以土霉素制药废水为研究对象进行电子束辐照试验,研究了辐照剂量、初始COD、pH及无机离子浓度对COD去除效果的影响。结果表明:电子束辐照技术可有效降低废水中的COD,COD去除率随辐照剂量的增加而不断升高,相同辐照剂量下COD去除率随废水初始浓度的升高而降低,辐照降解规律符合准一级动力学方程。废水最佳pH=5,且不同初始pH的废水经辐照后,水样pH均随辐照剂量的增加而不断降低,主要由产生的小分子有机酸所致。较高的无机离子浓度会导致COD去除率降低。     

臭氧降解水中CN~-活性的研究

国内每年约有千万吨含氰废水排入水体中,因氰化物属于剧毒物质,故研究臭氧氧化降解含氰废水的活性具有现实意义。研究了温度、臭氧使用量和pH值对含氰废水中氰根离子降解的影响。结果表明:臭氧降解含氰废水的处理效果好;处理质量浓度为150 mg/L的含氰废水,当反应温度为30℃,臭氧投加量为30 mg/min,臭氧浓度为9.4 mg/L,pH=10时,反应30 min后降解率可达99.8%;以臭氧降解氰根离子活性高,需要设备简单。     

电子束辐照对印染退浆废水的影响

采用不同辐照剂量的电子束辐照处理不同pH的印染退浆废水,考察电子束辐照对印染退浆废水的影响.在25～100 kGy剂量范围内,印染退浆废水COD去除率受辐照剂量影响不大,但受溶液pH的影响较大,中性、碱性退浆废水的COD去除率明显高于酸性;经100 kGy辐照后,中性、碱性印染退浆废水的BOD5减小,B/C升高,有利于废水的后续处理.     

高浓度含氰农药废水处理实例

该项目处理的水量为80m3/d,高浓度含氰农药废水的主要特点是难降解的有机物含量高,色度深,废水的主要难点是含有高氰化物和色度深,由于氰化物是毒性物质,处理该种废水的重要的是破氰和脱色,本项目采用的破氰分为络合和氧化两级处理,经过导电活性炭和铁粉组成的三维电解之后再用芬顿氧化处理之后的废水颜色和COD均得到有效处理,最后经过混凝沉淀和曝气生物滤池处理之后能够达标排放。该工艺具有处理效率高、处理成本低等优点。     

铝及其合金浸锌技术的发展及现状

浸锌是铝及其合金特殊前处理中较为常见的方式,在实际生产中占有重要地位。对浸锌前处理的碱蚀和出光的改进方法进行了总结。较为详细的阐述了铝及铝合金浸锌溶液从浓溶液到稀溶液,从单纯浸锌到多元合金浸锌,从有氰到无氰的发展过程。同时,对浸锌工艺的改良与发展及浸锌机理的研究进行了简要评述。     

加速器电子束辐照技术在污水处理中的应用

对电子束辐照技术的机理、辐照加速器装置及电子束辐照技术在污水处理中的研究应用现状进行了总结介绍,并对加速器电子束辐照技术的优缺点进行了分析。高能电子束的可控性能好,反应速率快,技术相对成熟,应用范围广,且不产生二次污染,特别是对一般技术难以降解处理的有毒物质,具有较好的技术和经济可行性。最后对加速器电子束辐照技术的大规模应用前景和研究重点进行了展望。     

Decomposition of Aqueous Naphthalene-1,5-Disulfonic Acid by Means of Oxidation Processes

Three different Advanced Oxidation Processes (ozonation at pH 7.5, electron beam irradiation and a combination ozonation/electron beam irradiation) have been applied to study decomposition of aqueous naphthalene-1,5-disulfonic acid (1,5-NDSA) with regard to mineralization and formation of biodegradable intermediates. Formation of biodegradable intermediates could not be indicated for any of the processes used; single electron beam irradiation treatment was the most efficient process for mineralization of organic carbon contained in aqueous 1,5-NDSA. Applied to a real wastewater effluent from a mixed municipal/industrial wastewater, electron beam irradiation with a radiation dose of 2 kGy was sufficient to reduce the concentrations of all naphthalene sulfonic acids and some of the alkylphenol ethoxylates also contained in that water by about 2 orders of magnitude.     

Initiation of Hydrogen Oxidation by a Pulsed Electron Beam

Results of an experimental study of initiation of a hydrogen-oxygen mixture by a pulsed electron beam are reported. It is shown that pulsed excitation of the gas mixture by an electron beam shifts the first ignition limit to temperatures below 30°C at pressures of 100–120 torr. The temperature interval through which the first flammability limit can be shifted by pulsed radiolysis is much greater than the values numerically predicted by other authors for a stoichiometric hydrogen-oxygen mixture under pulsed radiolysis.__________Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 3, pp. 46–51, May–June, 2005.     

电子束辐射对PTFE/GF摩擦磨损和压缩性能的影响

考察电子束辐射对玻璃纤维增强聚四氟乙烯(PTFE/GF)摩擦磨损性能和压缩性能的影响。结果表明,经电子束辐射后,PTFE/GF的耐磨性能和压缩性能均显著提高。当电子束辐射剂量为300 kGy时,PTFE/GF的耐磨性能提高了1.83倍,压缩弹性模量提高了0.8倍。分析认为,由电子束辐射引发的PTFE结晶度的提高使得PTFE/GF具有良好的耐磨性能和压缩性能。     

FT‐Raman studies of a range of polyimides subjected to high‐energy radiations at room and elevated temperatures

A range of polyimides have been subjected to electron beam radiolysis at different temperatures. These polyimides were chemically designed to suit space applications, being either transparent or having groups which provide oxidation resistance. The structural changes that occur in the polyimides, when subjected to electron beam irradiation doses up to 18.5 MGy and up to temperatures close to their glass transition temperatures, were studied using FT‐Raman spectroscopy. The range of polyimides studied included a series of perfluoropolyimides, a silicon‐modified polyimide, and Ultem. The changes in the Raman peak intensities of the different groups indicated scission reactions involving the imide rings and ether linkages. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1575–1582, 2006     

PHOTOCATALYSIS BY IRON-RICH MONTMORILLONITE FOR THE TREATMENT OF DYEING WASTEWATER

This study investigates the photocatalytic degradation of dyeing wastewater by iron-rich montmorillonite (MMt) under a 25 W low-pressure mercury lamp (λ = 254 nm, I = 48.4 μW/cm²). Exposing MMt to UV irradiation worked to catalyze the photobleaching of wastewater used in the dyeing process. COD removal efficiencies of 65.0% and 74.0% were achieved in 1 g/L MMt suspensions at a pH of 3 in the absence and presence of 30 min of UV irradiation, respectively. A decolorization efficiency of 71.4% was reached with 1 g/L MMt suspensions at a pH of 3 after 30 min of UV irradiation, while only 4.9% decolorization was attained in darkness. These results indicate that iron-rich MMt is a good photocatalyst for decolorization and COD removal in wastewater from dyeing processes. A low pH value is beneficial to the decolorization of dyeing wastewater. A preliminary photocatalytic mechanism is proposed: the iron in the MMt is responsible for the decolorization of the wastewater because it produces a highly oxidative species of hydroxyl radicals (^?OH).     

制备工艺对PTC复合材料阻温特性的影响

研究了密炼工艺对聚乙烯／炭黑复合材料室温电阻率及ＰＴＣ强度的影响,针对一定配方找到了最佳密炼工艺条件。电子束辐照交联能有效消除ＮＴＣ现象和提高材料的电性能循环稳定性,有助于制备低电阻率、高ＰＴＣ强度并具有较好电性能循环稳定及热敏开关特性和电路保护元件。     

含氰废水处理技术研究进展

叙述了含氰废水的主要处理方法和国内外含氰废水处理技术的研究动态,并介绍了一种新型的含氰废水处理方法——高能射线辐射降解法,阐述了该方法的基本原理、特点和应用情况,同时也指出高能射线处理含氰废水技术的研究和发展方向。     

Influence of electron beam treatment of jute on the thermal properties of random and two-directional jute/poly(lactic acid) green composites

In the present study, randomly aligned jute fiber/poly(lactic acid) (PLA) and two-directionally aligned jute fabric/PLA green composites with jute (50% by weight) treated with electron beam at different dosages (0, 5, 10, 30, 50, and 100?kGy) were fabricated by compression molding technique and the effect of electron beam treatment on their thermal properties was investigated in terms of thermal expansion, thermal stability, dynamic mechanical thermal property, and heat deflection temperature (HDT). The dynamic storage modulus and HDT of neat PLA were significantly increased by incorporating jute fibers or fabrics into PLA, whereas the coefficient of thermal expansion (CTE) and the damping property were decreased, reflecting the enhancement in the interfacial adhesion between the jute and the PLA by electron beam treatment with an optimal dosage of 10?kGy and the reinforcing effect by jute. The result exhibited that the thermal stability, storage modulus, and HDT of jute/PLA green composites were highest with the electron beam irradiation of jute at 10?kGy and lowest at 100?kGy, whereas the CTE and tan δ were lowest at 10?kGy and highest at 100?kGy. The thermal behavior of random jute/PLA green composites shows a similar tendency to that of 2D jute/PLA counterparts and the influence of electron beam irradiation on the thermal properties studied was consistent with each other. The thermomechanical analysis, dynamic mechanical thermal analysis, thermogravimetric analysis, and HDT results were in agreement with each other, showing a comparable effect of electron beam irradiation on composites thermal characteristics.     

铁屑腐蚀电池在工业废水治理中的应用

用铁屑腐蚀电池处理工业废水是一种比较新的方法,目前在印染废水,石油化工废水,砷氟废水及电镀废水等的治理方面得到应用,并得取了较好的效果,作者就其上述处理过程的机理作了简要介绍,也对他们近阶段在废水处理方面的工作进行了总结。