改性粉煤灰吸附对硝基苯酚的研究

研究了粉煤灰 (FA)和浸渍粉煤灰 (IFA)吸附水溶液中有害的对硝基苯酚 ,试验了颗粒大小、浸渍条件、p H值和温度等因素对吸附量的影响。结果表明 ,在稀溶液中进行吸附时 ,提高温度、减小粒径和 p H值 ,可增加粉煤灰对对硝基苯酚的吸附量 ;用 Al3+离子浸渍的粉煤灰具有较大的吸附量 ;吸附机理是多孔物质吸附和静电共同作用的过程。     

不同浸出毒性鉴别方法对垃圾焚烧飞灰浸出毒性鉴别的适宜性

以典型垃圾焚烧飞灰作为研究对象,考察中国、日本和美国的3种浸出毒性鉴别试验方法对飞灰浸出毒性鉴别的适宜性,研究了pH和液固比对飞灰中重金属浸出毒性的影响.结果表明飞灰中重金属的浸出主要受pH影响,在强酸(pH＜2)和强碱(pH＞12)条件下的浸出质量浓度高,而在中性(pH为9～11)条件下浸出质量浓度低.随着浸取剂与飞灰的液固比的增加,重金属的浸出量逐渐增加,达到最大浸出量后保持不变,但重金属的浸出质量浓度受稀释作用影响逐渐降低.相对于去离子水体系,醋酸缓冲体系浸取的重金属质量浓度较高,且浸出结果稳定.     

A Seven Months Prospective Study of the Respiratory Effects of Exposure to Ash from Popocatepetl Volcano, Mexico

This paper describes the 7 month follow-up of 35 non-smoker farmers exposed to suspended particles of volcanic ash of Popocatepetl volcano in central Mexico during a series of small explosive eruptions which occurred the last week of 1994 and the first week of 1995 as well as several smaller eruptions until April 1995. There was concern about the effect that the ash might have on the airways. Spirometric parameters and respiratory symptoms were recorded at the baseline and 7 months after the exposure. Analysis of spirometric data showed a significant low forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) that occurred during the major exposure period. This finding was possibly acute exposure-related because 7 months later, FVC and FEV1 increased to the normal predicted values. Self-reported respiratory and ocular symptoms showed a similar pattern. These findings are consistent with the hypothesis that short exposure to volcanic ash is associated with reversible inflammation of the airways. The reversibility was explained by the small total ash volume as well as by the non-fibrogenic nature of the Popocatepetl ash, because the content of free silica was less than 3.5%.     

钙质煤渣吸附剂脱除烟气中二氧化硫的实验研究

利用锅炉本身排出的煤渣作脱硫剂的基本核粒,配人少量的石灰,加水搅拌均匀,使石灰裹覆在煤渣颗粒表面,制成具有较大比表面积的钙质煤渣脱硫剂,用于烟气脱硫实验研究.实验结果表明,钙制煤渣脱硫剂比未经处理的煤渣脱硫率高,在一定的石灰添加范围内(10%～20%),脱硫率随石灰添加量的增加而增加,并存在一最佳用量.     

采用烧结法降低垃圾焚烧飞灰浸出毒性的研究

采用电感耦合等离子体发射光谱仪（ICP-AES）对垃圾焚烧飞灰和造粒烧结后试样中重金属的浸出量进行分析.研究表明,随着烧结时间的增加和烧结温度的提高,大多数重金属浸出毒性都有所降低.对造粒后的飞灰物料进行低温烧结处理,烧结工艺参数可初步定为造粒直径为15mm,烧结温度为950℃-1100℃,烧结时间约为20min.     

市政垃圾焚烧飞灰中添加CaO抑制PCDD/Fs生成试验探究

采用自制装置,以CaO作为PCDD/Fs生成抑制剂,对市政垃圾焚烧飞灰做热处理。通过试验考察温度、CaO添加量等因素对飞灰中PCDD/Fs生成的影响。结果表明：质量分数为5%的CaO添加可以减少80%的PCDD/Fs生成。     

陡电干除灰设备治理和改进

针对陡河发电厂干除灰系统易出现内管脱落、磨损及逆止阀密封不严等问题系统地进行了分析,对频发缺陷进行了治理和改进,确保干除灰系统安全运行。     

脱硫灰-石灰石湿法脱硫石膏中杂质悬浮分离实验

根据脱硫灰及石膏的特性,在无挡板平底圆筒搅拌槽内,对脱硫石膏中的杂质进行完全离底悬浮分离实验,研究结果表明,完全离底悬浮搅拌时,悬浮高度比越低,越有利于杂质分离。对于直径D≥24cm的搅拌槽,当桨叶离底高度cb=4cm,桨径槽比d／D=0．65,杂质分离效率叼最高,约82％;当直径D=20cm时,杂质分离效率η随d／D的增大而增大,桨叶离底间距减小,杂质分离效率受d／D影响程度减小;当桨叶离底高度cb=4cm时,随着搅拌槽直径D的增大,杂质分离效率总体呈现增大趋势,降低桨叶离底高度cb杂质分离效率变化较大;进行完全离底悬浮分离后,石膏纯度提高。     

底泥生长基质中重金属的迁移特征及生物有效性

河道底泥中重金属含量较高,重金属的迁移性及生物有效性是限制疏浚底泥土地施用或用作废弃场地修复基质资源化利用途径的主要因素。以沈阳细河待疏浚底泥为材料,通过盆栽实验的方法研究了河道底泥与碱性粉煤灰、炉渣和锯木屑配比基质中重金属在紫花苜蓿体内累积、迁移及生物有效性的变化。结果发现,配比底泥基质上紫花苜蓿生物量、株高及株径均好于纯底泥处理,其中底泥、粉煤灰、炉渣、锯木屑以2：0．5：0．5：0．5配比的s2处理中紫花苜蓿生物量是纯底泥处理的11．7倍。与底泥对照相比,配比底泥基质上植株体内重金属含量极显著降低,而且地上部重金属含量显著低于根部含量;底泥基质中紫花苜蓿地上部和根部对Cd、Cu、Pb、Zn的富集系数（BCF）显著低于底泥处理,但转移系数（TF）无显著变化,富集系数（BCF）和转移系数（TF）均小于1．0。紫花苜蓿种植后底泥基质中重金属含量显著低于农用污泥重金属控制标准,除Cd含量略高外,Cu、Pb和Zn含量低于土壤环境质量三级标准。这些结果表明,城市重污染河道底泥经过合理处置后,重金属浓度、活性及生物有效性降低,在其土地施用或废弃地修复中可以用作一些耐性植物的生长基质。     

Comparison of CaO’s effect on the fate of heavy metals during thermal treatment of two typical types of MSWI fly ashes in China

Both grate and fluidized bed incinerators are widely used for MSW incineration in China. CaO addition for removing hazardous emissions from MSWI flue gas changes the characteristics of fly ash and affects the thermal behavior of heavy metals when the ash is reheated. In the present work, two types of MSWI fly ashes, sampled from both grate and fluidized bed incinerators respectively, were thermal treated at 1023–1323 K and the fate of heavy metals was observed. The results show that both of the fly ashes were rich in Ca and Ca-compounds were the main alkaline matter which strongly affected the leaching behavior of heavy metals. Ca was mostly in the forms of Ca(OH)₂ and CaCO₃ in the fly ash from grate incinerator in which nascent fly ash particles were covered by Ca-compounds. In contrast, the content of Ca was lower in the fly ash from fluidized bed incinerator and Ca was mostly in the form of CaSO₄. Chemical reactions among Ca-compounds caused particle agglomeration in thermal treated fly ash from grate incinerator, restraining the heavy metals volatilization. In thermal treated fly ash from fluidized bed incinerator, Ca was converted into aluminosilicates especially at 1323 K which enhanced heavy metals immobilization, decreasing their volatile fractions as well as leaching concentrations. Particle agglomeration hardly affected the leaching behavior of heavy metals. However, it suppressed the leachable-CaCrO₄ formation and lowered Cr leaching concentration.