生活垃圾焚烧飞灰制陶瓷砖表征

为了探索生活垃圾焚烧飞灰资源化利用途径,在对飞灰化学组成及矿物成分分析的基础上,利用飞灰、黄陶土、耐火砂及长石研制陶瓷砖,最佳配比方案为:飞灰20%,黄陶土60%,长石10%,耐火砂10%,分析了最佳配比制品的吸水率、抗压强度、微观结构及水平振荡浸出毒性。结果表明:飞灰属SiO2-Al2O3-金属氧化物体系,主要矿物成分是钙硅酸盐及铝硅酸盐等,可用于制陶瓷砖;最佳配比制品达MU15强度等级,满足抗风化的要求;随煅烧温度的升高,制品结构不断密实化,960℃烧成的制品显示出完全烧结的特点,960~1 000℃烧成的制品中出现明显的晶化、玻璃化过程。最佳配比制品重金属浸出毒性完全达标,重金属的浸出率与坯体相比大大降低。     

高架道路交通噪声动态模拟

为研究高架道路噪声的分布规律,结合微观交通仿真、车辆噪声排放和传播原理,对高架道路交通噪声进行动态模拟.该方法能得到逐秒变化的实时声压级.能反映交通噪声随时间的动态变化,且方便应用多项指标评估.研究表明:等效声级和累计声级的误差达到±2 dB;高架道路两端的防撞护栏在离道路边缘32m的垂直面上的声压衰减影响到10m左右...     

燃煤电厂脱硫粉煤灰理化特性及排放特征

以徐州某电厂脱硫粉煤灰为研究对象,分别研究了脱硫粉煤灰的粒径分布、微观形态、矿物组成和元素含量4方面的物理化学特性,并在此基础上研究了该电厂脱硫粉煤灰颗粒及其中所含元素的排放特征.结果显示,该电厂粉煤灰颗粒物以拉径在3～45 μm的颗粒为主,数量占80％以上,并以表面光滑的球形颗粒居多,并含有少量表面附着小颗粒晶体的球形颗粒和表面有孔的球形颗粒,以及一些不规则颗粒,其主要的矿物组成是莫来石和石英.该电厂粉煤灰颗粒物的排放因子达到了1.95 kgt.粉煤灰的元素组成选取了Mn,Zn,Cr,Cu,Pb,Ni,Cd 7种元素,其中Mn在粉煤灰中的含量最高,相对应的Mn元素的排放因子也高,达到了125.04 g/t.由于该厂粉煤灰含有一定量的重金属元素,随意堆放和处理会对人体和环境产生一定的影响,因此必须做好粉煤灰的处理与处置,降低粉煤灰对人体和环境的危害作用.     

Debromination of decabromodiphenyl ether by organo-montmorillonite-supported nanoscale zero-valent iron：Preparation, characterization and influence factors

An organo-montmorillonite-supported nanoscale zero-valent iron material(M-NZVI) was synthesized to degrade decabromodiphenyl ether(BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmorillonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30–90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased.     

Reduction and characterization of bioaerosols in a wastewater treatment station via ventilation

Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxidation ditch process were diminished by ventilation.Conventional sampling and detection methods combined with cloning/sequencing techniques were applied to determine the groups,concentrations,size distributions,and species diversity of airborne microorganisms before and after ventilation. There were 3021 ± 537 CFU/m3 of airborne bacteria and 926 ± 132 CFU/m3 of airborne fungi present in the WWTS bioaerosol.Results showed that the ventilation reduced airborne microorganisms significantly compared to the air in the WWTS. Over 60% of airborne bacteria and airborne fungi could be reduced after4 hr of air exchange. The highest removal(92.1% for airborne bacteria and 89.1% for fungi) was achieved for 0.65–1.1 μm sized particles. The bioaerosol particles over 4.7 μm were also reduced effectively. Large particles tended to be lost by gravitational settling and small particles were generally carried away,which led to the relatively easy reduction of bioaerosol particles0.65–1.1 μm and over 4.7 μm in size. An obvious variation occurred in the structure of the bacterial communities when ventilation was applied to control the airborne microorganisms in enclosed spaces.     

Antimony smelting process generating solid wastes and dust：Characterization and leaching behaviors

A large amount of solid waste has been produced by the antimony smelting process in the＂World Capital of Antimony＂, Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag,arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 104 and 3.16 × 105mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste.     

Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy

A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure（XANES） spectroscopy was applied to characterize the extracellular polymeric substances（EPS） of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA,polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra.Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS（loosely bound EPS） and TB-EPS（tightly bound EPS） of all the biofilms in LB medium than in R2 A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS,suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms.     

祁连山老虎沟12号冰川积雪中飞灰颗粒物的特征

冰川积雪中的飞灰颗粒物可指示由大气沉降的人类活动污染物.本研究基于2012年6月在青藏高原东北缘的祁连山老虎沟12号冰川夏季野外观测取样、实验室扫描电子显微镜与X射线能谱仪联用系统(SEM-EDX)分析了积雪粉尘中球形颗粒物的特征信息,以弄清冰川区沉降的球形飞灰颗粒物的理化特征及其环境意义.结果表明,在所选取的雪层不同深度的9个积雪样品中,都存在着一定数量的飞灰颗粒,这些颗粒物通常是人类生产活动中的化石燃料高温燃烧所形成的.基于EDX能谱分析了飞灰颗粒物的化学元素成分组成,认为沉积在祁连山冰川积雪中的飞灰主要分为3种类型,分别为"富Si类"、"富Fe类"和"富Ti类"颗粒物.总体上,"富Si类"和"富Fe类"颗粒占了球形飞灰颗粒的绝大部分.这些不同组分的飞灰代表了污染物的不同生产活动来源,其平均粒径要相对大于雪层中自然来源的所有矿物粉尘颗粒物,反映了大气传输远距离中密度对粉尘颗粒的重要性.结合NOAA Hysplit气团后向传输轨迹分析认为,中亚地区和我国新疆地区城市、及研究区周边的工业燃烧物通过大气传输是祁连山老虎沟12号冰川积雪中飞灰颗粒的主要可能来源.     

碱熔融法合成NaA和NaX型粉煤灰沸石的品质表征

以粉煤灰为原料采用碱熔融法合成了2种单一沸石矿物种的NaA和NaX型沸石,并对产物的结构、性能和应用指标进行了详细表征.经x射线衍射和IR光谱分析,表明合成产物是无杂晶生成的NaA和NaX型沸石相;在扫描电镜观察下,产物分别具有NaA和NaX型沸石的立方体和八面体晶体骨架结构.DTA分析表明了合成产物中沸石水的存在,且产物热稳定性较好.通过对比,粉煤灰合成的NaA和NaX型沸石的比表面积达到了相应商品沸石的66.9%和83.6%;孔容为41.1%和70.2%;阳离子交换容量(CEC,cation exchange capacity)为82.93%和84.31%.通过比较化学组成表明,大规模应用合成产物不会对环境造成危害.     

密相塔半干法烟气脱硫塔内加湿降温及其对脱硫效率的影响

为了实现密相塔半干法脱硫工艺的精确加湿进一步提高系统脱硫效率,利用推导出的传热传质计算方法,得到烟气温度降低和加水量的关系.结合3组密相塔半干法工程实际数据,发现理论计算值和实测值误差区间仅为2.9％ ～5.4％.通过选取河北某钢厂210 m2烧结烟气密相塔半干法脱硫项目实际在线检测数据,发现循环脱硫灰含湿量为3％的系统脱硫效率整体高于含湿量为5％和4％的样品,最大值达93.56％.通过粒度分析、扫描电镜、X射线衍射及差热-热重对2种不同含湿量的循环脱硫灰进行表征,结果表明,含湿量为3％的循环脱硫灰较含湿量为5％的样品粒径小、比表面积大,无团聚现象,物相分析还证实相对于含湿量为5％样品,其Ca(OH)2和结晶水含量少,几乎都是CaSO4和CaS03干态物质,因此脱硫反应进行彻底,脱硫效率较高.