Control of chlorinated aromatic compounds from a municipal solid waste incinerator using limestone addition

In this study, limestone powder was directly added to synthetic MSW, which was fed into a small‐scale fluidized bed incinerator. The concentration of CBzs and CPs in the flue gas were measured before and after a secondary combustion air injection. Finally, the PCDDs and PCDFs concentrations were also measured in the flue gas after the secondary combustion zone. The CaCO₃ added to synthetic MSW not only controls HCl in the flue gas, but suppresses the formation of chlorinated aromatic compounds like CBzs, CPs, PCDDs, and PCDFs. The main mechanisms to control the formation of chlorinated aromatic compounds was more likely related to the suppression of catalytic capability of flyash than the HCl reduction in the flue gas. However, the NO concentration was increased by catalytic reaction of limestone in the fluidized bed.     

危险废物焚烧设施二噁英类排放特征及周边土壤污染调查

调查了13座不同类型的危险废物焚烧设施及二噁英类排放模式及部分设施土壤的污染水平.结果表明,排放浓度同焚烧处理量没有显著的关系.4—6氯代PCDD/Fs和7—8氯代PCDD/Fs呈现出了不同的排放特征.4—6氯代PCDF/PCDD比值为60.58±1.98(95%置信区间),较通用的总PCDF/总PCDD比值更适于描述危险废物焚烧设施二噁英排放的特征.使用PCA及聚类分析方法将设施排放模式归类为3种模式.分布模式同焚烧设施炉型、处理量以及尾气处理方式等因素相关性并不显著.2,3,4,7,8PeCDF对I-TEQ的贡献为35%—45%,并与I-TEQ具有很高的相关性.厂区土壤中二噁英浓度水平约为8—14ngI-TEQ.kg-1,周边土壤浓度为1—4ngI-TEQ.kg-1左右,均处于较低水平,调查设施周边土壤的使用目前尚无明显风险.危险废物设施对周边土壤的环境风险需要进一步评估.     

Baseline levels of PCDD/Fs in soil and herbage samples collected in the vicinity of a new hazardous waste incinerator in Catalonia,Spain

The construction in Constantí (Catalonia, Spain) of a new hazardous waste incinerator (HWI), which is the first one in Spain, finished in 1999. In order to determine the temporal variation (1996–1998) in the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the vicinity of the new HWI, 40 soil and 40 herbage samples were collected (1998) at the same sampling points in which samples had been taken two years before (1996). Each sample was analyzed for PCDDs and PCDFs by high resolution gas chromatography/high resolution mass spectrometry. In the 1996 survey, PCDD/F concentrations in soils ranged from 0.13 to 24.20 ng I-TEQ/kg (d.m.), with median and mean values of 0.67 and 1.68 ng I-TEQ/kg (d.m.), respectively. In the present study, PCDD/F concentrations ranged from 0.12 to 17.20 ng I-TEQ/kg (d.m.), with a median value of 0.75 ng I-TEQ/kg (d.m.) and a mean value of 1.59 ng I-TEQ/kg (d.m.). In turn, in the present study PCDD/F concentrations in vegetation ranged from 0.14 to 2.01 ng I-TEQ/kg (d.m.) (median and mean values: 0.23 and 0.31 ng I-TEQ/kg, respectively), while in the 1996 survey PCDD/F concentrations ranged from 0.24 to 1.22 ng I-TEQ/kg (d.m.) (median and mean values: 0.53 and 0.61 ng I-TEQ/kg, respectively). According to the present (1998) and the previous (1996) levels of PCDD/Fs found in soils and vegetation, the area under potential influence of the new facility shows a rather low contamination by these compounds. The current results should be useful to establish the environmental impact of the HWI.     

生活垃圾焚烧厂贮坑沥滤液的负压蒸发预处理研究

采用负压蒸发法处理上海市某大型生活垃圾焚烧发电厂贮坑沥滤液,实验研究了沥滤液蒸发过程中冷凝液组分的变化特征.结果表明:生活垃圾焚烧厂贮坑沥滤液中含有高质量浓度的挥发性污染物,低碳醇和碳原子数不大于7的挥发性有机酸(VFA)约占沥滤液中有机碳质量浓度的50%;沥滤液直接蒸发可将原液转化为原液量的84%,不含氨氮,有机物质量浓度为原液的21%,且90%以上为VFA及低碳醇的冷凝液,以及有机物质量浓度浓缩了4.4倍,适于焚烧处理的浓缩液;通过蒸发处理,沥滤液的处理难度大大降低,蒸发用能可取自焚烧热能回收后的低温位热能,降低了蒸发处理的费用.      

喷消石灰脱除垃圾焚烧炉尾气中HCl和SO2的试验研究

在日处理200t进口流化床垃圾焚烧炉上,进行烟气喷水降温加上喷消石灰粉末脱除尾气中的酸性气体HCl和SO2的试验研究,HCl和SO2浓度由布袋除尘器出口的在线气体分析仪测得,结果表明HCl和SO2的去除率在Ca/Cl摩尔比等于9时分别为80%和20%,说明该法消石灰利用率较低,宜改为半干法脱除HCl和SO2酸性气体,以便降低吸收剂用量,提高运行的经济性.     

垃圾焚烧飞灰熔融渣特性分析

研究了熔融固化产物--熔融渣的特性.结果表明:熔融渣的主要成分为CaO,Al₂O₃和SiO₂,其含量占总质量的99%左右,而SO₃,K₂O,Na₂O和Cl在熔融渣中的含量明显降低,其质量分数分别从原始飞灰中的10.74%,8 58%,3.81%和20.59%降低到0.17%,0.04%,0.23%和0.11%;熔融渣中碱性氧化物和酸性氧化物的含量基本相同,碱度接近于1.0;重金属Cr和Zn的固定率较高,分别为94.2%和81 7%,而Cu,Pb和Cd的固定率较低,分别为31.4%,14.5%和24.6%;采用美国TCLP方法测试的熔融渣中重金属浸出量均低于国家危险废物浸出毒性鉴别标准限值.      

热解焚烧技术处置医疗废物的影响因素与工况控制研究

针对热解焚烧技术处置医疗废物的特点,分析处置工艺运行参数对稳定工况的影响规律,确定医疗废物在热解焚烧技术炉内稳定焚烧的工艺参数,指出送风量与气化炉、燃烧炉的温度关系是焚烧系统控制的关键。通过对某型焚烧炉的测试,得到了送风量与气化炉和燃烧炉的温度关系曲线。测试结果表明,实时动态调控气化炉和燃烧炉的送风量,能够实现医疗废物的稳定焚烧。     

不同垃圾焚烧炉产生的PCDD/Fs和PCBs同类物的分布

要应用高分辨气相色谱一质谱联用技术，测定了3种垃圾焚烧炉产生的飞灰中17种PCDD／Fs和12种共平面PCBs的浓度及毒性当量，比较了PCDD／Fs和PCBs同类物分布的差异．结果表明，流化床焚烧炉和炉排焚烧炉产生的PCDD／Fs多于PCBs，而气化熔融焚烧炉产生的PCBs多于PCDD／Fs；产生的PCBs对总毒性当量的贡献都比较小；3种焚烧炉产生的PCDD／Fs同类物具有相似的浓度分布；流化床焚烧炉和炉排焚烧炉产生的PCBs同类物具有相似的浓度分布，而气化熔融焚烧炉产生的PCBs同类物分布与其他两种焚烧炉差别较大．     

垃圾焚烧炉飞灰的低温玻璃固化初步研究

在研究我国城市生活垃圾焚烧炉飞灰的毒性特征和高温灼烧特性的基础上，试验了几种常用玻璃熔制助溶剂、烟气净化产物中的成分对飞灰的溶融温度和熔融减量的影响，以实现低温玻璃固化。实验发现受热温度越高、时间越长，飞灰减量越大；B2O3、硼砂、CaF2对飞灰助溶效果明显，而废玻璃、CaO、CaCl2能使悄灰溶融后形成的玻璃态物质地均匀、少孔。按一定比例同时加入硼砂、CaF2、废玻璃、CaO、CaCl2于飞灰中，混合物的熔融温度降到1000℃以下，大大低于飞灰自身的熔融温度（1200℃）。对该熔融物在空气中淬火形成的玻璃态物质按标准方法浸沥，选择测量了浸出液中铅、汞、镉、砷的浓度，初步发现低温玻璃态物质对重金属铅和镉具有较好的固化效果，而对汞有砷的固化效果尚不确定。     

炉排型城市生活垃圾焚烧炉排气中二

选择四种规模不同的炉排型生活垃圾焚烧炉,分别对其排放烟气中的二