Arsenic content and distribution pattern in Chinese coals

About 500 samples of coal, pyritic coal balls, pyritic gangue and coal seam gangue were collected from different coal basins and geologic periods of coal formation to determine the arsenic (As) content and distribution pattern in China. The Permian-Carboniferous and Jurassic coals in the North China Plate and Northwest China account for nearly 85% of total Chinese coal reserves and data showed that As content ranged from 0.1 to 94?mg?kg^?1, with the majority between 1 and 14.9?mg?kg^?1. The As content of some Late Permian coals in Southwest Guizhou Province and stone coal in the South Qinling Mountain area were exceedingly high (30–534?mg?kg^?1), but the majority of coal in the Southwest Guizhou Province contained low to medium amounts. Only the coals, which are situated in or near igneous rocks and are not considered a part of Chinese coal reserves, possessed unusually high As content (>30?mg?kg^?1). Arsenic was also concentrated in pyritic coal balls and the pyritic gangue of the coal seam with values ranging from 21.5 to 142.46?mg?kg^?1 and an average of 69?mg?kg^?1 in Shaanxi and 78?mg?kg^?1 in Shandong. Arsenic contents in coal gangue in the Northwest and North China Plate is about 0.2–15?mg?kg^?1, a little lower than coals in the same seam. Washing gangue (waste from coal washing) generally contained more As than coal, because the washed gangue has more pyrite than the natural gangue (black shale). Washing coal reduced the content of the pyritic sulfur, heavy metals and As. Based on amounts of coal used with different As content in Chinese coal reserves, the average As content of Chinese coals is about 4.5?mg?kg^?1.     

黄铁矿催化类Fenton反应处理阳离子红X-GRL废水

基于对天然矿物黄铁矿进行SEM、EDS表征的基础上,以黄铁矿为非均相类Fenton催化剂,以偶氮染料阳离子红X-GRL为目标污染物,考察了催化剂双氧水用量、溶液初始pH值、阳离子红X-GRL初始浓度、反应时间等因素对染料脱色效果的影响.结果表明,在H2O2浓度为26.6mg/L、矿用量1g/L、溶液初始pH值6.4左右的条件下,反应2min后,染料脱色率达95%左右.进行了黄铁矿在水溶液中的酸性氧化实验并且考察了Fe2+、SO42-浓度及溶液pH随矿重复利用次数的变化规律.初次使用的黄铁矿具有很强的酸性氧化特性,反应过程中伴随着大量Fe2+、SO42-及H+的溶出.染料的快速脱色主要是均相Fenton反应作用的结果.黄铁矿作为一种新的催化剂大大提高了类Fenton反应的催化活性,而且该新型类Fenton反应能克服传统Fenton反应适用pH范围小的局限性,拓展了Fenton反应在废水处理中的应用.     

煤及其灰渣中的汞

研究了东北、内蒙古东部煤炭中汞的含量分布以及煤中汞向燃烧产物中迁移的规律。煤中汞含量高于土壤,并和煤中全硫分及灰分呈显著正相关。煤中汞在锅炉飞灰中被富集,在底灰中被分散。飞灰粒径越小汞含量越高,显示表面富集特征;飞灰中90％以上的汞存在于＜0.125mm粒子上。飞灰中汞占煤中汞总量23.1％～26.9％,从烟囱排出的汞占56.3％～69.7％,燃煤排放的汞是大气中汞的重要来源     

黄铁矿与硫粉配合提高污泥重金属的淋滤效果

通过接种嗜酸性硫杆菌复合菌株(氧化亚铁硫杆菌与氧化硫硫杆菌)并采用序批式试验,研究了黄铁矿与硫粉2种底物配合使用对污泥中重金属生物淋滤效果的影响.结果表明,2种底物配合可加速污泥中重金属(Zn, Cu)的浸出,显著提高其去除率.经过18d的生物淋滤,在2种底物配合并接种的处理中,Zn和Cu的去除率分别可达89.2%,56.5%;而在单独加黄铁矿并接种的处理中两者的去除率分别为12.0%, 0.9%;单独添加硫粉并接种处理中分别为85.2%,37.6%,进一步验证了生物淋滤技术去除污泥中重金属的可行性.     

厦门煤渣与粉煤灰开发应用可行性研讨

厦门的年耗煤量已突破 1 50万吨 ,煤渣与粉煤灰的出路是政府与公众所关注的问题。 1 986年与 1 996年相隔 1 0年的两次放射性水平监测与研究相互印证表明 ,厦门以煤渣砖为建材的建筑物 ,放射性水平低于砖混、砖木、泥木、花岗岩等类的建筑物。厦门煤渣与粉煤灰的核素含量 ,均低于《建筑材料用工业废渣放射性物质限制标准》,从而为厦门煤渣与粉煤灰的开发与推广应用提供了科学依据 ,指出了光明前景     

深埋地下结构工程环境水水质异常成因分析

分析了某抽水蓄能电站地下厂房硐室群开挖引起环境水水质异常的成因。对工程区进行大范围的环境水pH值检测和代表性渗水部位水样的成分分析后发现,环境水的pH值、SO42-含量和总铁含量特征在一些部位发生了明显改变:水质呈强酸性、SO42-含量和总铁含量高且分布不均匀。结合岩石成分分析和现场黄铁矿矿化点的调查,认为该抽水蓄能电站地下厂房硐室群环境水水质的异常是由地层中不均匀分布的黄铁矿矿化点在开放条件下的氧化造成的,与厂房区锚孔中使用的化学充填材料无关。鉴于当前还没有有效防止强酸性腐蚀的材料,建议加强勘察期间水文地质条件特别是深部水文地质条件的研究,及早掌握和预测深部结构工程开挖、运行过程中由于环境条件改变可能导致的水质改变,以便采取预防措施。