中国火葬场二噁英类污染物排放及减排技术研究

对中国某火葬场9具遗体进行了二(口恶)英类污染物排放测试,测试结果表明,烟气中二(口恶)英类物质总浓度为89～350ng·m-3,毒性当量浓度为1.5～5.4ng·m-3;PCDFs的总浓度高于PCDDs的总浓度;以此估算中国2004年火化遗体过程中二(口恶)英类污染物的年排放量为11.2～46.9 g·a-1.通过实验分别研究了布袋除尘器、布袋除尘器加不同厚度的活性炭纤维毡组合对火化遗体烟气中二(口恶)英类污染物的去除效果.结果表明,布袋除尘器去除火化烟气中二(口恶)英类污染物的效率为57.4%;布袋除尘器分别与厚度为5、15mm的活性炭纤维毡组合去除火化烟气中二(口恶)英类污染物的效率分别为64.0%和89.2%.     

环境中的二恶英

二恶英主要来源于化工，造纸生产，工业化学放心弃物和垃圾焚烧等，本文对二恶英的理化性质，分析方法，毒性，来源，污染的产生及其环境效应对人体健康的影响进行了评述。     

城市生活垃圾焚烧飞灰熔融处理的进展

针对城市生活垃圾焚烧产生飞灰的处理以及由此引发的二次污染问题,阐述了飞灰的污染特性,讨论了各种飞灰处理技术的优缺点,分析了熔融处理技术在降低飞灰中重金属浸出毒性和彻底分解其中的二恶英所具有的优越性,为飞灰的无害化和资源化处理提供参考。     

The New Jersey Toxics Reduction Workplan for Ny-Nj Harbor: Distribution of Pcdd/Fs in Ambient Waters

As part of the NJ Toxics Reduction Workplan for NY-NJ Harbor, ambient water samples were collected at fifteen locations along the tidal portions of the Hackensack, Passaic, Raritan, Rahway and Elizabeth Rivers, and in Newark Bay, the Arthur Kill, and Kill van Kull. A Trace Organics Platform Sampler was used to collect a total of 75 suspended sediment phase samples between June 2000 and May 2002. These samples were analyzed for spatial and wet vs. dry weather trends in the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs; modified USEPA Method 1613b). Mean total PCDD/F (tPCDD/F) concentrations at the sampling locations ranged between 3.8 and 41.5 ng/g. On average, OCDD accounted for almost 80% of the tPCDD/F concentrations; mean total [PCDD/F – OCDD] concentrations ranged between 0.84 and 5.20 ng/g at the sampling locations. Mean 2,3,7,8-TCDD concentrations ranged between 0.003 and 0.28 ng/g, with the highest concentrations (> 0.10 ng/g) along the tidal Passaic and lower Hackensack Rivers, and in upper Newark Bay. Mean tPCDD/F Toxic Equivalency Quotients (TEQ) ranged between 45 and 344 TEQ pg/g, with the highest levels found in the lower Passaic River. Toxicity was primarily driven by 2,3,7,8-TCDD concentrations in the Passaic and Hackensack Rivers, and in Newark Bay. Examples of congener distribution patterns at some of the sampling locations are also presented.     

生活垃圾焚烧废气中二噁英监测采样研究

对当前国内生活垃圾焚烧废气中二噁英监测相关标准和技术规范的解读和实践操作后,认识到生活垃圾焚烧废气中二噁英监测采样的现状及不足.针对不同类型烟道,不同采样时间和不同采样时间间隔分别进行了研究.实验结果表明,同一稳定气流的排放源中,水平烟道和垂直烟道测试二噁英毒性当量排放浓度水平相当;满足监测采样量要求下,不同采样时间和采样时间间隔对二噁英监测结果并无显著差异,对此给出几点相应采样建议.     

关于医疗垃圾飞灰中二噁英在惰性气氛下的低温热脱附研究

以医疗垃圾焚烧炉布袋除尘器前管道内飞灰(BG)及布袋除尘器后飞灰(AG)为对象,研究不同温度及时间段下其在管式炉中的热脱附特性.结果表明,在低温氮气气氛下,热脱附作用较为明显,2种飞灰中的二噁英都有了不同程度的脱除,其中布袋前飞灰中二噁英的脱除率为82.9%～99.9%之间,毒性当量脱除率为77.3%～99.8%,布袋后飞灰中二噁英的脱除率为66.8%～99.8%之间,毒性当量脱除率为43.5%～99.6%.检测收集到的实验尾气,发现了二噁英的存在,且在300～350℃这个温度段生成量最多,且生成的有毒二噁英同系物中以OCDD为主.通过比较发现,当温度为400℃,加热时间为45 min时2种飞灰中的二噁英脱除效率最高.鉴于惰性气氛下的热脱附对处理飞灰中的二噁英具有较好的作用,可将其大规模应用于实际工程中.     

Dioxin formation in pulp and paper mills of India

Samples of effluents, sludge, pulp, final products (paper) and soil were collected from the identified pulp and paper mills in India. The samples were analysed for 2,3,7,8-tetrachloro-dibenzo-p-dioxin (2,3,7,8-TCDD) and other dioxin congeners and precursors. Pulp and paper mills using chlorine for the bleaching process showed the presence of 2,3,7,8-TCDD in effluent samples. In the effluent and pulp samples from mills where chlorine dioxide was used as a bleaching agent, the 2,3,7,8-TCDD congener ranged from below the detection limit 0.05 to 0.12 ngL⁻¹/ngg⁻¹. The relative standard deviation of reproducibility and the percent recovery of 2,3,7,8-TCDD were 2.07 and 82.4% in pulp and 2.8 and 92% in effluent, respectively. The 1,3,6,8-TCDD was the only other major dioxin congener found in the treated and untreated effluent and sludge samples. However, dichlorobenzene, trichlorophenyl, and hexachlorobiphenyl were detected in all samples. The formation of dioxins can be minimised by replacing chlorine with chlorine dioxide in bleaching processes in pulp and paper mills.     

北京市典型废弃物焚烧源2010—2017年二NFDA1英排放特征和减排效果分析

分析2010—2017年北京市三类典型废弃物焚烧源的废气二NFDA1英排放监测数据,计算排放因子和排放量,评估减排政策成效,并分析不同排放源达标排放时同类物分布特征异同和变化规律,探讨影响排放的重要因素。结果表明: 5家焚烧源平均排放浓度为 0.008～0.069 ng/m³(以TEQ计,下同),废气二NFDA1英排放因子为 0.027～1.7 μg/t,2016年向空气中排放的二NFDA1英量为 0.002 5～0.058 g;生活垃圾、危险废物和医疗废物焚烧源的低、高氯代同类物质量分数比的平均值分别为接近于 0.5、大于0.5和小于0.5,危险废物焚烧源的 ∑PCDFs、∑PCDDs质量分数比的平均值大于2; 123478-HxCDF和123678-HxCDF质量浓度接近且线性相关,具有相近的生成机理和去除效率; I-TEQ变化趋势与∑PCDFs质量分数的变化趋势基本一致,活性炭喷射和布袋除尘的去除效率是影响二NFDA1英排放的重要因素之一;危险废物焚烧源HWI1随运行时间增加排放浓度增加,而及时更换烟道管壁有助于消除“记忆效应”的不良影响。     

生活垃圾焚烧发电厂二恶英对人体健康的风险评价

介绍了生活垃圾焚烧过程中二恶英的产生机理、对人体的危害及控制措施,以某生活垃圾焚烧发电厂环境影响评价为例,提出了二恶英对人体健康风险评价方法,同类项目环境影响评价提供借鉴。     

垃圾焚烧烟气净化和二噁英污染物的控制技术

采用焚烧法处理城市生活垃圾,在我国正得到广泛的推广应用,但焚烧也带来二噁英污染,它严重威胁着人类的健康,世界各国正在采取积极措施控制。文章介绍了二噁英的结构、性质和形成机理,从焚烧前、焚烧中、焚烧后三个方面评述了国内外近年来所发展的对二噁英污染物的控制技术。