五氯酚在飞灰表面低温反应生成二口恶英特性

在管式炉上研究了不同试验条件飞灰/五氯酚生成二口恶英的分布特性.采用色质联机(HRGC/LRMS)测定了PCP中以及生成产物中的二口恶英含量.结果表明，生成产物中的二口恶英主要以气态形式存在，总的二口恶英中以PCDDs为主，比例高于97％，PCDDs中主要同系物是六至八氯代PCDDs.分析了飞灰含量以及氧含量对二口恶英生成的影响，二口恶英生成量随着飞灰中含碳量的增加而增大，氧含量是控制二口恶英生成的关键因素，氧含量在6.7％时生成的二口恶英总量及毒性当量值最小.对试验中产生的二口恶英进行了质量平衡，为进一步研究垃圾焚烧过程中二口恶英排放以及分布特性打下基础.     

三氯新中二噁英同类物的指纹特征

作为三氯新生产过程中的一种副产物,二口恶英污染物在三氯新中的存在已经引起了广泛关注。采用高分辨气相色谱-质谱测定了三氯新样品中的二口恶英同类物,共检测到7种2,3,7,8位氯取代同类物,即2,3,7,8 TCDD(四氯代二苯并二口恶英)、1,2,3,7,8 PeCDD(五氯代二苯并二口恶英)、1,2,3,4,6,7,8 HpCDD(七氯代二苯并二口恶英)、2,3,7,8 TCDF(四氯代二苯并呋喃)、1,2,3,7,8 PeCDF(五氯代二苯并呋喃)、2,3,4,6,7,8 HxCDF(六氯代二苯并呋喃)、1,2,3,4,6,7,8 HpCDF(七氯代二苯并呋喃),其含量分别为0 25、0 44、2 65、0 88、2 15、1 02和4 21pg·g-1。四至八氯代二口恶英总量中,四氯代二苯并呋喃最多。在检测到的7种有毒二口恶英中,对毒性当量贡献较大的同类物有2,3,7,8 TCDD和1,2,3,7,8 PeCDD。三氯新样品中二口恶英同类物分布的指纹特征与环境样品差别较大,二口恶英类污染物的产生与三氯新的生产工艺有关。     

五氯酚在飞灰表面低温反应生成二(口恶)英特性

在管式炉上研究了不同试验条件飞灰/五氯酚生成二(口恶)英的分布特性.采用色质联机(HRGC/LRMS)测定了PCP中以及生成产物中的二(口恶)英含量.结果表明,生成产物中的二(口恶)英主要以气态形式存在,总的二(口恶)英中以PCDDs为主,比例高于97%,PCDDs中主要同系物是六至八氯代PCDDs.分析了飞灰含量以及氧含量对二(口恶)英生成的影响,二(口恶)英生成量随着飞灰中含碳量的增加而增大,氧含量是控制二(口恶)英生成的关键因素,氧含量在6.7%时生成的二(口恶)英总量及毒性当量值最小.对试验中产生的二(口恶)英进行了质量平衡,为进一步研究垃圾焚烧过程中二(口恶)英排放以及分布特性打下基础.     

城市污水污泥焚烧二次污染物控制研究进展

介绍了污泥焚烧技术的现状:它是目前国内外研究最多的处理污泥技术之一,其优势在于处理速度快,减量化程度高,能够利用污泥中的热值。阐述了焚烧过程中产生的重金属、二口恶英、氮氧化物、硫氧化物等的排放限制了污泥焚烧技术的推广和应用,因此对污泥焚烧二次污染控制的研究就显得非常重要。表明了研究污泥焚烧后产生的大量灰渣的处理和利用技术也是污泥焚烧研究的一个重要方面。     

城市垃圾焚烧过程中二(口恶)英的产生与防治

本文简要地介绍二(口恶)英的性质,着重分析了城市垃圾焚烧过程中二(口恶)英的来源及其在焚烧产物中的分配和含量,并在此基础上指出了垃圾焚烧产生二(口恶)英的防治途径.     

环境中二噁英的来源、危害及预防措施

介绍了二口恶英的结构、性质、来源及在环境中的危害 ,预防二口恶英的具体措施可从避免使用产生二口恶英的产品、控制焚烧烟气中二口恶英的排放量等方法来实现     

基于硫基循环抑制技术的危险废物焚烧炉二(口恶)英排放的控制

依托某危险废物焚烧炉(50 t·d^-1)开发了一套硫基循环抑制及飞灰低温热处置联用控制二(口恶)英排放的中试平台,研究了该系统对硫基的循环累积能力及对烟气中二(口恶)英合成的抑制能力.系统利用吸附剂吸附了烟气中SO₂,并在低温热处置装置中将吸附剂中SO₂脱附回烟气中,实现SO₂循环.试验结果表明,该系统能连续稳定运行,对烟气中的SO₂具有一定的富集累积能力,添加一定量外源硫基物质后系统中烟气SO₂能维持在100 mg·m^-3左右,对整体二(口恶)英排放因子的去除率达80%以上.可见,该硫基循环抑制技术对废物处理过程中二(口恶)英减排具有重要指导价值,且长期稳定运行对控制二(口恶)英低排放起关键作用,但该中试系统的相关参数需进一步优化.     

抑制垃圾焚烧中二英合成的中试研究

基于循环流化床垃圾焚烧炉的实际工况,验证碳酸氢钠对约400℃的烟道气中二(口恶)英合成的抑制能力。实验结果表明,循环流化床形式的垃圾焚烧炉烟道气中的二(口恶)英浓度变化较大;在烟道气流量约为25万m~3/h、温度约为400℃工况下,烟道内形成二(口恶)英的抑制率随着碳酸氢钠喷射量的增加而增加,当碳酸氢钠的喷射速率达到1. 1 t/h时,二(口恶)英的抑制率达到约90%;当碳酸氢钠连续喷射时间不低于2 h且喷射量不低于0. 7 t/h,烟道内二(口恶)英的抑制率高于60%。     

新的二噁处理方法

焚烧废物会产生二口恶口英。它们存在于焚烧灰烬中 ,可能会污染土壤。常规的把二口恶口英经 30 0～ 5 0 0℃温度分解除去的做法既费时又费钱。欧洲专利 0 914877报道 ,日本栗田工业公司的新工艺能在较低温度下迅速分解二口恶口英。。研究人员只把胺和铵化合物加入到灰烬或土壤中 ,当加热到 15 0～ 2 0 0℃时 ,这些胺和铵化合物气体与二口恶口英中的氯气反应产生无毒的产物。据称 ,如果反应 2 0～ 40ｍｉｎ ,将获得足够高的分解新的二噁处理方法     

有关二(口恶)(口英)的若干问题

1999年欧洲发生的二(口恶)(口英)污染食品事件,国内传媒也曾大量报道,事过之后,就不再提起.但我国的科技界应当对有关二(口恶)(口英)的问题进行深入研究,防止发生类似事件.     

造纸废水污泥处理技术及资源化利用研究

造纸废水污泥是一种富含纤维素、半纤维素、多种有机物的固体物质,其有效处理是解决造纸污泥资源化利用和环境保护的首要问题。本文概述了国内外造纸废水污泥处理技术的发展现状和研发成果。介绍了造纸污泥在多个领域的资源化利用。     

Removal of dioxins and PCB from fish oil by activated carbon and its influence on the nutritional quality of the oil

Fish oils are well-known sources of nutritionally valuable components such as the n-3 FA EPA and DHA as well as the fat-soluble vitamins A, D, and E. However, some fish oils can be contaminated with considerable amounts of dioxins and dioxin-like PCB. The most important challenge during fish oil refining is to remove these contaminants without altering the levels fining is to remove these contaminants without altering the levels of nutritionally valuable compounds and the oxidative status and stability of the oil. Treatment with an apolar adsorbent, e.g., activated carbon (AC), seems to be the most efficient process today. Very little information about the adsorption of different dioxin and PCB congeners is available. Four grades of AC were evaluated for their efficiency in removing these compounds. In addition, the effects of the treatment on the nutritional and oxidative quality of the oil were evaluated. After treatment of contaminated cod liver oil [5.4 ppt toxic equivalents (TEQ) polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), 18.1 ppt TEQ dioxin-like PCB] with 0.5% AC, almost all PCDD/F and up to 80% of the dioxin-like PCB could be removed. AC showed low affinity for mono-ortho PCB (<30% removal), which could be explained by their noncoplanar structure. Removal efficiencies were dependent on the grade and percentage of AC used. The treatment of contaminated cod liver oil caused no important effects on oil quality or FA composition in the conditions tested.     

含油污泥离心处理技术研究进展

含油污泥,简称油泥,是在石油开采、运输、炼制及含油污水处理过程中产生的含油固体废物。油泥中含有数百种有毒有害化合物,美国环保署将其列为优先污染物,我国也将油泥列入国家危险废物名录。目前,我国含油污泥的产量巨大,油泥以及由油泥引起的污染土壤的无害化处理已成为一个亟待解决的科学和技术问题。主要介绍了国内离心技术处理含油污泥研究的现状及进展,对这些方法进行了评价和比较,并对今后的研究方向提出建议。     

Resources recovery of oil sludge by pyrolysis: kinetics study

Oil sludge, if unused, is one of the major industrial wastes requiring treatment from petroleum refinery plants or the petrochemical industry. It contains a large amount of combustibles with high heating values. The treatment of waste oil sludge by burning has certain benefits; however, it cannot provide the useful resource efficiently. On the other hand, the conversion of oil sludge to lower molecular weight organic compounds by pyrolysis not only solves the disposal problem but also has the appeal of resource utilization. The major sources of oil sludge include the oil storage tank sludge, the biological sludge, the dissolve air flotation (DAF) scum, the American Petroleum Institute (API) separator sludge and the chemical sludge. In this study, the oil sludge from the oil storage tank of a typical petroleum refinery plant located in northern Taiwan is used as the raw material of pyrolysis. Its heating value of dry basis and low heating value of wet basis are about 10681 kcal kg⁻¹ and 5870 kcal kg⁻¹, respectively. The removal of the moisture from oil sludge significantly increases its heating value. The pyrolysis of oil sludge is conducted by the use of nitrogen as the carrier gas in the temperature range of 380–1073 K and at various constant heating rates of 5.2, 12.8 and 21.8 K min⁻¹. The pyrolytic reaction is significant at 450–800 K and complex. For the sake of simplicity and engineering use, a one‐reaction kinetic model is proposed for the pyrolysis of oil sludge, and is found to satisfactorily fit the experimental data. The activation energy, reaction order and frequency factor of the corresponding pyrolysis reaction in nitrogen for oil sludge are 78.22 kJ mol⁻¹, 2.92 and 9.48 × 10⁵ min⁻¹, respectively. For precise use, the two‐ and three‐reaction models are proposed to describe the pyrolysis results. Among the three models proposed, the three‐reaction model gives the best fit. These results are very useful for the proper design of the pyrolysis system of the oil sludge under investigation. © 2000 Society of Chemical Industry     

桨叶式干燥机热干燥处理制革污泥的排放特性

进行了使用桨叶式干燥机进行污泥热干燥处理的实验研究,分析在不同的温度下污泥的干燥效果、气体排放和冷凝水产生情况。实验结果表明,污泥在干燥过程中会释放出氨气、挥发性有机酸（甲酸、丙酸）和烷烃（庚烷）等挥发性有机污染物,且升高温度能够降低干燥机出料含水率,并能够通过影响水解及脱羧反应从而增加干燥过程排放的气体量及冷凝水的COD值。通过对比冷凝前后的气体排放量,表明冷凝操作有利于降低二次污染。     

污泥中典型新兴有机污染物的污染现状及对污泥土地利用的影响

污水生物处理过程中很多较强毒害作用的有机污染物转移到活性污泥中,进而影响了污泥的土地利用。本文依据对生态环境及人类健康的影响,以7种受关注度比较高的典型新兴有机污染物为对象,综述了其在污泥中的赋存状况,同时对这些污染物可能对污泥土地利用产生的影响进行了分析。最后,对7种新兴有机污染物在污泥中的赋存状况进行了总结,并对相关研究方向进行了展望,指出应继续分析和监测污泥中有机污染物,尤其是新兴有机污染物对生态环境的影响和危害,并深入研究污泥中这些物质的有效降解途径与方法,使污泥能够安全地进行土地利用。     

城市污泥慢速热解过程中氮的转化规律

利用热重-质谱联用(TG-MS)技术研究城市污泥慢速热解特性及含氮气体产物的生成规律,同时利用原位红外光谱仪实时检测固体表面官能团的变化。研究结果表明:初沉污泥在500℃之前热解已基本完成,二沉污泥由于添加了矿物质盐类,在700℃左右仍有一个较大的失重峰;二沉污泥热解过程HCN和NH₃总生成量均小于初沉污泥,即二沉污泥所加矿物质抑制了HCN和NH₃释放;但温度大于400℃时所加矿物质对HNCO生成具有一定促进作用;污泥中蛋白质热分解会产生环酰胺类物质、含氮杂环化合物和腈类物质,并最终转化为HCN,这是污泥热解过程中HCN的主要来源;400℃以下NH₃主要来自铵盐分解和HCN转化,蛋白质热分解对于NH₃生成贡献很小;400℃以上基本检测不到NH₃生成,即较高温度下挥发分二次反应对NH₃生成几乎没有影响;300~480℃,污泥中木质素裂解产生了大量含氧自由基,促使HCN转化为N₂O,HNCO则最终转化成了NO。     

福建省二恶英类POPs污染现状及防治对策

本文利用福建省2009年和2007年的二恶英类POPs调查数据,分析了福建省二恶英类POPs排放源的分布特征以及存在问题,并提出相关防治对策建议。     

Effect of Ozonation on Degradation of Organochlorine Compounds in Biosludge of Pulp and Paper Industry

The waste-activated sludge in the pulp and paper industry has been classified as hazardous waste due to the presence of organochlorine compounds. The fate of organochlorine compounds during ozonation of biosludge as well as subsequent treatment in activated sludge process has been studied. Ozonation of biosludge at 45.3 ± 2.1 mg O₃/g dry solid dosage resulted in 23 ± 2 and 26 ± 4% removal of adsorbable organic halides and extractable organic halides compounds, respectively. Out of 12 chlorophenolic compounds identified by USEPA for regulation, 10 compounds were detected in the biosludge and 19–68% removal of the individual compounds was observed during ozonation. High molecular weight chlorinated compounds were decomposed to low molecular weight ones with partial dechlorination. The ozonation followed by biological treatment can remove more than 80% of organochlorine compounds.     

Abatement of Organic Pollutant Concentrations in Residual Treatment Sludges: A Review of Selected Treatment Technologies Including Drying

As a result of increasing population, industrialization, and effluent quality, sludge production has increased worldwide. Organic micropollutants in sludge have become a more critical environmental health concern compared to heavy metals. New sludge disposal regulations limit persistent organic pollutants (POPs) in addition to conventional organic indicators like total and dissolved organic carbon. This study aims at providing a brief review on POP concentration in the sludge in different regions of the world, sludge regulations, assessment of conventional biological sludge stabilization methods according to their ability to remove POPs, and discussions on alternative sludge treatment methods. The impact of sludge treatment unit operations including conditioning, thickening, mechanical and thermal dewatering, and biological and thermal stabilization on sludge management is also discussed in the context of organics. The occurrence and removal of micropollutants such as absorbable organic halogen compounds (AOX), nonylphenol and nonylphenol ethoxylates (NPE), di-2-(ethyl-hexyl)-phthalate (DEHP), dibenzo-p-dioxins and furans (PCDD/F), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) are also evaluated specifically for sludge treatment unit operations. A concise discussion is also included on different drying technologies suitable for drying of sludge.