多氯联苯焚烧处置时烟灰中的二恶Ying

专门用于销毁含多氯联苯（ＰＣＢｓ）固体废弃物的中试焚烧炉，焚烧排放物中含有微量剧毒二恶Ｙｉｎｇ（ＰＣＤＤ／Ｆｓ），应用同位素稀释ＨＲＧＣ／ＨＲＭＳ方法测定了烟灰中的ＰＣＤＤ／Ｆｓ含量，以１７种有毒同族体的含量可计算出样品的２，３．７，８－ＴＣＤＤ毒性为４７．２ｎｇ／ｇ。     

Morphology of single inhalable particle in the air polluted city of Shijiazhuang, China

In the typical air polluted city of Shijiazhuang,single inhalable particle samples in non-heating period,heating pened,dust storm days,and snowy days were collected and detected by SEM/EDS(scanning electron microscopy and energy dispersive X-ray spectrometry).The particle morphology was characterized by the 6 shape clusters,which areirregular square,agglomerate,sphere,floccule,column or stick,and unknown,by quantitative order.The irregular square particles are common in all kinds of samples;sphere particles are more,and column or stick are less in winter samples;in the wet deposit samples,agglomerate and floccule particles are not found.The surface of most particles is coarse with fractal edge,which can provide suitable chemical reaction bed in the polluted atmospheric environment.New formed calcium crystal is found to demonstrate the existence of neutralized reaction,explaining the reason for the high SO2 emission and low acid rain frequency in Shijiazhuang.The three sorts of surface patterns of spheres are smooth,semi-smooth,and coarse,corresponding to the element of Si-dominant,Si-Al-dominant,and Fe-dominant.The soot particle is present as floccule with average size around 10 μm,considerably larger than the former reported results,but wrapped or captured with other fine particles to make its appearance unique and enhance its toxicity potentially.The new formed calcium crystal,the 3 sorts of sphere surface patterns,and the unique soot appearance represent the single inhalable particle's morphology characteristics in Shijiazhuang City.     

用氧化锌烟灰制备饲料级氧化锌

以锌冶炼厂氧化锌烟灰为原料,经NH3-NH4HCO3溶液浸取、Zn粉置换除杂、用自制偏钛酸吸附除A s等工序制备饲料级氧化锌。实验结果表明:氧化锌烟灰在NH3-NH4HCO3溶液中于40℃浸取2h,Zn浸出率可达96%~98%;当偏钛酸加入量为12.5g/L、吸附1h时,产品中A s的质量分数低于0.000 3%。采用该工艺制得的饲料级氧化锌符合HG/T2792—1996《饲料添加剂氧化锌》的质量标准。     

机动车尾气烟尘中烷烃和有机酸的组成

本研究采用直接采样方法分别对11辆柴油公交车和20辆汽油小汽车的排气管壁积尘进行采集,再使用气相色谱与质谱联用仪(GC-MS)对样品中的烷烃和有机酸进行定性以及定量分析.结果表明,公交车(C_(14)~C_(30))和小汽车(C_(14)~C_(33))正构烷烃质量分数分别为1.31~149.08μg·g~(-1)和15.35~556.03μg·g~(-1),公交车尾气尘中正构烷烃以C_(20)为主峰碳,小汽车中正构烷烃以C_(29)为主峰碳,且小汽车生成更多高沸点长链烷烃.公交车中姥鲛烷和植烷总质量分数分别是15.24μg·g~(-1)和21.79μg·g~(-1),小汽车中姥鲛烷和植烷总质量分数分别是2.31μg·g~(-1)和2.69μg·g~(-1),公交车和小汽车姥鲛烷和植烷的比值分别为0.699 4和0.858 7,植烷和十八烷的比值分别是0.356 5和0.747 2.脂肪族有机酸的质量分数变化都比较大,公交车和小汽车中其变化范围分别为0.01~40.87μg·g~(-1)和3.8~113.7μg·g~(-1),公交车烟灰中质量分数最大的有机酸是3-羟基丁酸,丙二酸(C_3)和丁二酸(C_4)比的最大值为5.93,小汽车烟灰中质量分数最高的正构烷酸是正十六烷酸(C_(16)),芳香族有机酸的质量分数范围分别为5.05~31.70μg·g~(-1)和0.1~228.38μg·g~(-1).     

炼铜烟灰制取高纯度硫酸锌

采用炼钢烟灰制取高纯度硫酸锌,研究了制取条件对收率和产品质量的影响,试验结果表明,控制适宜的酸浸条件,锌浸取率≥９８％,铁浸取率可控制在０．０２％以下,当酸浸工艺条件液固比为３：１,温度８０－９０℃,硫酸加入量３９ｇ／Ｌ（酸浸液）滴酸时间１．５ｈ浸取时间２ｈ,再用空气和过氧化氢氧化除去溶液中的铁,产品中硫酸锌含量≥９９％,铁含量可降至０．５ｍｇ／Ｌ以下。     

催化剂对汽车发动机烟灰燃烧性能的影响

将汽车排气管中收集到的烟灰与不同催化剂混合组成干混试样。利用ＴＧ－ＤＴＡ技术,考察了不同催化剂对烟灰的助燃作用。发现催化剂存在时烟灰的燃烧特征温度Ｔｍａｘ有较大程度的降低。催化剂的助燃活性：ＮｉＯ／Ａｌ２Ｏ３〉ＣｕＯ／Ａｌ２Ｏ３〉Ｖ２Ｏ５／Ａｌ２Ｏ３〉Ｐｄ／Ａｌ２Ｏ３〉Ａｇ２Ｏ／Ａｌ２Ｏ３〉Ｃｒ２Ｏ３／Ａｌ２Ｏ３〉ＣｅＯ２／Ａｌ２Ｏ３,与金属氧化物的生成焓（－ΔＨ）有一定对应关系,随着－ΔＨ的增加     

火焰原子吸收光谱法测定烟囱烟灰中的铊

提出了火焰原子吸收光谱法测定冶炼厂烟囱烟灰中铊的分析方法。试验表明:方法检测限(3σ)为0 11mg/L,回收率在92%～103%之间,相对标准差<3%,方法简便快速。     

Investigation of basic properties of fly ash from urban waste incinerators in China

Basic properties of fly ash samples from different urban waste combustion facilities in China were analyzed using as X-ray fluorescence （XRF）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）. The leaching toxicity procedure and some factors influencing heavy metals distribution in fly ash were further investigated. Experimental results indicate that the fly ash structures are complex and its properties are variable. The results of XRF and SEM revealed that the major elements （〉10000 mg/kg, listed in decreasing order of abundance） in fly ash are O, Ca, Cl, Si, S, K, Na, Al, Fe and Zn. These elements account for 93% to 97%, and the content of Cl ranges from 6.93% to 29.18 %, while that of SiO2 does from 4.48% to 24.84%. The minor elements （1000 to 10000 mg/kg） include Cr, Cu and Pb. Primary heavy metals in fly ash include Zn, Pb, Cr, Cu etc. According to standard leaching test, heavy metal leaching levels vary from 0 to 163.10 mg/L （Pb） and from 0.049 to 164.90 mg/L （Zn）, mostly exceeding the Chinese Identification Standard for hazardous wastes. Morphology of fly ash is irregular, with both amorphous structures and polycrystalline aggregates. Further research showed that heavy metals were volatilized at a high furnace temperature, condensed when cooling down during the post-furnace system and captured at air pollution control systems. Generally, heavy metals are mainly present in the forms of aerosol particulates or tiny particulates enriched on surfaces of fly ash particles. The properties of fly ash are greatly influenced by the treatment capacities of incinerators or the variation of waste retention time in chamber. Fly ash from combustors of larger capacities generally has higher contents of volatile component and higher leaching toxicity, while those of smaller capacities often produce fly ash containing higher levels of nonvolatile components and has lower toxicity. The content of heavy metals and leaching toxicity maybe have no convincing correlation, and high alkali content of CaO greatly contribute to leaching toxicity of heavy metal and acid neutralization capacity against acid rain.