Treatment of Bone Waste Using Thermal Plasma Technology

Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an investigation of bone waste treated using thermal plasma technology is presented. A high-temperature plasma torch operated at 25.2 kW was used to treat bone waste for seven minutes. The bone waste was finally changed into vitric matter and lost 2/3 of its weight after the treatment. The process was highly efficient, economical, convenient, and fuel-free. This method could be used as an alternative for disposal of bone waste, small infectious animals, hazardous hospital waste, etc.

Fast inactivation of microbes and degradation of organic compounds dissolved in water by thermal plasma

The multifunctionality and the advantages of thermal plasma for the fast inactivation of viable cells and degradation of organic compounds dissolved in waste water are presented.A complete bacterial inactivation process was observed and studied using a thermal plasma treatment source with very short application times,in particular for Staphylococcus aureus bundle spore survival.The survival curves and analyses of the experimental data of the initial and final densities of S.aureus bacteria show a dramatic inhibitory effect of the plasma discharge on the residual bacteria survival ratio.As the exposure time increased,the inactivation process rate increased for direct exposure more than it did for indirect exposure.The evaluation of direct and indirect exposure was based on the analysis of the ultraviolet spectrum from the absorbance spectra of the organic compound dye called benzene sulfonate（C（16）H（11）N2Na O4S）and of viable cells called S.aureus.Organic compounds were degraded and viable cells were killed in a short time by thermal plasma.Moreover,analyses of total carbon,total organic carbon,and total inorganic carbon showed a fast decrease in organically bound carbon,however,this was not as fast as the absorbance spectra revealed by the exposure time increasing more for direct exposure than indirect exposure.After 100 s of exposure to the organic compound dye the removal had a maximun of 40%for samples with indirect exposure to the plasma and a maximum of 90%for samples with the direct exposure.For both samples,where some organic contaminants still remained in treated water,four electrolytes（KCl,Na Cl,Na2SO4,and CH3COONa）were added to be effective for complete sterilization,reaching a purity of 100%.A proposal is made for an optimized thermal plasma water purification system（TPWPS）to improve fast inactivation of microbes and the degradation of organic compounds dissolved in water（especially for direct exposure rather than indirect exposure）using a hybrid plasma torch with an electrical power of 125 kW（500 V–250 A）producing a high-temperature（10 000 K–19 000 K）plasma jet with a maximum gas consumption of 28 mg s^-1.

L型等离子体熔融炉预热升温数值模拟及优化研究

L型等离子体熔融炉因其具有热解气化效率高、抑制核素挥发等特点,在低中放射性废物处理方面具有独特优势。由于炉内等离子体炬的高温特性,在预热阶段采用等离子体炬升温存在温度不可控的问题,从而可能造成炉内温度分布均匀性差,严重时甚至会造成炉内局部耐火材料的损伤甚至失效。文章针对L型等离子体熔融炉搭建了有限元数值模拟模型,探究了热风进口分布位置及等离子体炬安装位置对预热效果的影响。结果表明,对称式送风布置形成热风对冲区导致炉内热量传递受阻,而采用单侧热风进口布置可避免上部竖炉和下部炉膛的交界拐角处的低温区,使炉内温度梯度较小。通过试验对比,开启3个单侧送风口,进风总流量为200 m^(3)/h、热风温度为200℃、等离子体炬(76 kW)相对位置布置夹角为40°时,炉内整体温度分布均匀性较优。文章结论可为L型等离子体高温熔融炉的设计及运行提供实际指导,提升设备可靠性及安全性。

硅基钽酸锂异质晶圆键合工艺研究

5G移动通信的发展对声表面波滤波器提出了高频、小型化、集成化的要求。相较于传统压电体单晶材料,采用硅基压电单晶薄膜材料制备的声表面波滤波器具有高频、低插入损耗、高温稳定性等优势,是高性能声表面波器件发展的核心基础材料。Smart-Cut^(TM)是制备硅基压电单晶薄膜材料的主要方法,键合工艺是其中的核心工序,键合质量决定了硅基压电单晶薄膜晶圆材料的质量,并影响器件性能。本文通过低温直接键合工艺,对等离子活化、兆声清洗、预键合、键合加固四道工序展开优化,最终实现了键合强度高达1.84 J/m^(2)、键合面积超过99.9%的高质量硅基钽酸锂异质晶圆键合。

食品非热加工技术研究进展

为满足消费者日益增长的对食品质量的消费需求,食品工业致力于采用温和的方法加工食品,而与热加工相比,食品非热加工技术可在有效杀菌与钝化酶的同时较好地保持食品原有营养物质与活性物质,因此近年来颇受欢迎。本文介绍了超高压处理、超声处理、冷等离子体、脉冲强光技术等非热加工技术研究进展,以期为食品非热加工技术的进一步发展提供理论依据。

Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene （PP） films are modified by a dielectric barrier discharge （DBD） with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups.

Improving Hydrophobicity of Glass Surface Using Dielectric Barrier Discharge Treatment in Atmospheric Air

Non-thermal plasmas under atmospheric pressure are of great interest in industrial applications, especially in material surface treatment. In this paper, the treatment of a glass surface for improving hydrophobicity using the non-thermal plasma generated by dielectric barrier discharge （DBD） at atmospheric pressure in ambient air is conducted, and the surface properties of the glass before and after the DBD treatment are studied by using contact angle measurement, surface resistance measurement and wet flashover voltage tests. The effects of the applied voltage and time duration of DBD on the surface modification are studied, and the optimal conditions for the treatment are obtained. It is found that a layer of hydrophobic coating is formed on the glass surface after spraying a thin layer of silicone oil and undergoing the DBD treatment, and the improvement of hydrophobicity depends on DBD voltage and treating time. It seems that there exists an optimum treating time for a certain applied voltage of DBD during the surface treatment, The test results of thermal aging and chemical aging show that the hydrophobic layer has quite stable characteristics. The interaction mechanism between the DBD plasma and the glass surface is discussed. It is concluded that CHa and large molecule radicals can react with the radicals in the glass surface to replace OH, and the hydrophobicity of the glass surface is improved accordingly.

Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air

Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the

介质阻挡放电等离子体转化H2S-CO_(2)酸气制合成气的影响因素研究

H_(2)S和CO_(2)两种有害酸性废气常共存于煤化工、天然气化工及石油化工等重要化工生产中,造成了工业设备及管线腐蚀,必须就地进行无害化处理。采用介质阻挡放电等离子体催化实现一步转化H_(2)S-CO_(2)混合酸气制合成气,将具有强腐蚀性、毒性的H_(2)S和温室气体CO_(2)无害化,又产出合成气,完成了以废治废的酸性废气资源化再利用。研究了用于H_(2)S-CO_(2)一步转化制合成气的介质阻挡放电等离子体反应各参数对转化反应的影响,进行了不同参数的对比研究,考察并揭示了比能量密度(SEI)、放电结构、放电频率、放电间隙以及放电区域长度等与H_(2)S-CO_(2)转化制合成气反应性能的内在关联。在此基础上设计并构建了多管并联介质阻挡放电等离子体反应系统。

增进模具可靠性的表面强化技术

从等离子体热处理、热喷涂法、气相沉积、熔盐浸镀法等方面介绍了增强模具可靠性的表面强化技术及其优缺点。指出正确运用表面强化技术可以增强模具使用的可靠性,提高模具的使用寿命和性能。

应用冷等离子体净化尾气中NO的研究

本文设计了轻便的电晕放电装置 ,并用其进行了冷等离子体去除NO的实验研究 ,得到了NO的去除率随放电管的输入功率、NO的初始浓度以及气体的流量而变化的对比曲线。在流量较小 (≤ 0 .0 5m3 /h)或者浓度较低 (≤ 15 0×10 -6)的情况下 ,本文所设计的装置去除NO的效果较好 (>80 % )。该装置体积小、重量轻、功耗低 ,加以改进 ,对于实际的汽车尾气排放控制 。

低温等离子体-光催化净化空气污染物技术研究进展

低温等离子体光催化技术是一项新兴的技术,它结合了低温等离子体技术和光催化技术的优点,在环境领域有着广阔的应用前景。近年来的研究初步表明,它在治理空气污染物的方面具有较好的性能。介绍了低温等离子体光催化净化空气污染物技术的基本原理,并从去除挥发性有机物、氮氧化物、杀菌除臭等方面介绍了国内外对该技术的研究,指出了今后研究发展方向。

低温等离子体灭菌及生物医药技术研究进展

低温等离子体的生物学效应包括对微生物的致死作用和对动物细胞的刺激作用,分别造就了一批灭菌技术和临床医药技术。本文介绍了等离子体灭菌技术在医疗器械、水和空气净化、食品和包装材料处理等方面的应用。其中已商业化的医疗器械灭菌器主要分低气压和常压两种,低气压等离子体灭菌器的灭菌体积较大,常压等离子体灭菌器的优点则是结构简单和便于操作。等离子体灭菌技术用于水、空气、食品等领域由于能耗、效率、化学残留等问题尚未商业化。在医药技术方面,近十年来开发的等离子体技术和装备成功运用于龋齿、皮肤、伤口、癌症等的处理,部分已进入临床应用。将来的研究重点在于明确等离子体与细胞之间的相互作用机理,并开发出更高效、实用的用于各相关行业的等离子体技术和装备。

铋酸钠催化大气压介质阻挡放电降解苯胺

在柱-板式介质阻挡放电体系中投加铋酸钠催化剂,研究了该体系的放电光谱特性及对苯胺模拟废水的协同处理效果,考察了pH值、苯胺初始质量浓度及催化剂投加量等因素对降解率的影响,探讨了铋酸钠协同介质阻挡放电(DBD)催化降解苯胺的机理。实验结果表明,柱-板式电极结构放电过程中辐射出了紫外光和可见光,300~450nm之间出现高强度N2第二正带谱线。初始浓度100mg/L苯胺废水被处理10min后,投加0.2g/L催化剂时溶液的TOC去除率最高,比单独DBD低温等离子体体系提高14.11%。在碱性条件下,苯胺和TOC的去除率均好于酸性和中性条件。XRD检测结果显示铋酸钠在反应前后峰值位置未发生明显改变。

放射性废物热等离子体处理熔融炉温度分布数值模拟及熔渣玻璃化配方初步研究

目前核电厂放射性废物处理工艺具有高增容性的特点,为最终废物处置带来很大的压力。针对高增容的处理现状,介绍了放射性废物减容处理技术的研究重点——热等离子体技术;通过数值模拟分析热等离子体熔融炉内的温度分布,给出固定床熔融炉关键部位的最高可能温度约为1 445℃,结合可选耐火材料探讨了炉体建造的可实现性。选取核电站3种典型的放射性技术废物进行模拟玻璃化配方实验,在限定的熔融温度条件下,得到符合我国核行业标准要求的玻璃固化体。

废气治理低温等离子体反应器的研究进展

低温等离子体技术用于废气治理成为近年来的研究热点,而低温等离子体反应器的研制正是其重要内容。本文详细介绍了用于废气治理的各种电晕放电反应器、介质阻挡放电反应器以及等离子体-催化反应器的结构特点和放电特性,综合比较了上述反应器在能量效率、降解产物的选择性和工业应用等方面的特点,并提出了今后的研究方向。

纳米Ag颗粒复合薄膜的制备及其吸收特性

利用磁控溅射分层制备Ag和SiO2薄膜,通过快速热处理,使Ag颗粒富集在复合薄膜的表面。研究了Ag膜层厚度、退火时间、退火温度和退火方式对Ag颗粒形貌的影响,以及Ag颗粒致密度对其共振吸收的影响。结果表明:通过控制每层Ag膜的厚度,可有效控制Ag颗粒形貌。当每层金属为2 nm、退火温度为500℃时,形成的颗粒粒径大小均匀且致密度较高。通过间断退火可有效降低Ag颗粒的粒径。发现Ag颗粒表面等离子共振吸收并没有随颗粒粒径的减小而明显降低,甚至提高。这和以往的报道不同。通过深入研究金属颗粒表面等离子体产生机理,发现其表面等离子共振吸收增强的原因是致密度较高的颗粒表面能级与费米能级差值较大,Ag颗粒内部的电子向颗粒表面迁移越多,形成新的费米能级E'F的电子数就越多,表面等离子共振吸收就越强。最终得出了金属颗粒共振吸收不单纯依赖于金属粒径、和颗粒的致密度也有很大关系的结论。

垃圾焚烧飞灰的熔融固化实验

利用热等离子体发生器装置对垃圾焚烧飞灰进行熔融固化处理,研究飞灰在熔融过程中重金属的迁移特性,并对熔融得到的产品的重金属浸出特性进行实验研究.结果表明:熔融固化技术使熔渣中重金属的浸出浓度得到非常有效的限制,其中Cd和Cr的浸出浓度检测不到,Ni、Pb、Cu、Zn的浸出浓度分别为0.0078 mg/l、0.0519 mg/l、0.0767 mg/l和0.2073 mg/l,远远低于国家的规定值,也低于飞灰水泥固化体的浸出浓度.相比于原始飞灰,熔融得到的熔渣具有非常致密的微观结构,比表面积降低了近95%,密度增加了近145%.

低温等离子体处理柴油机尾气的研究进展

柴油机由于具有较高的热效率和输出功率,以及良好的耐久性和燃油经济性,已经越来越多的被用于汽车、商务车、卡车以及各类重型交通工具中。柴油机相比汽油机有更低的碳排放,然而,柴油机尾气中却含有大量的NO_x和PM等污染物,随着环保要求的日益严格,如何全面的治理柴油机尾气中的污染物,成为当今研究的热点。文中分析了柴油机尾气污染物的成分及其特点,介绍了常规的柴油机尾气后处理系统及其存在的问题,最后详细阐述了应用低温等离子体技术辅助治理柴油机尾气的方法及其研究进展,并提出了一种应用等离子体技术治理柴油机尾气排放的推荐方案。

钛基纳米金刚石涂层场发射阴极的工艺改进

钛基纳米金刚石涂层场发射阴极适于大面积制备,但原始工艺制备出的样品场发射性能较低.为提高样品的性能,对原始工艺进行了改进:首先,改变分散液成分,在原分散液中加入表面活性剂以改善金刚石纳米粉的分散效果;其次,改变真空热处理(HFCVD)系统的热丝结构使样品热处理时的温度场更加均匀;最后,在原工艺基础上增加表面处理环节,用射频氢等离子体对金刚石纳米粉涂层进行表面处理以降低样品的场发射阈值.经过工艺改进,样品的阈值场强由6.3 V/μm降低至1.9 V/μm,在17.6 V/μm场强下的场发射电流密度由56.1μA/cm2提高到61μA/cm2.