Comparison on the phytoextraction efficiency of Bidens pilosa at heavy metal contaminated site in natural and electrokinetic conditions

The plant samples of Bidens pilosa were collected from a coal gangue vacant site and its surrounding area, located in central China, to study the remediation effect of the plant species on heavy metal(HM) contamination in both natural and electrokinetic(EK) conditions. The analytical results showed that the effect of phytoextraction and bioconcentration on the heavy metals in the sample of the EK group is more significant than those in the other control group. Compared with the results of natural condition, under the EK condition the concentrations of cadmium(Cd), lead(Pb), copper(Cu) and zinc(Zn) in the stems and leaves of the Bidens pilosa increased to 0.40 mg/kg, 4.23 mg/kg, 7.27 mg/kg, 830.24 mg/kg, respectively,with their increments of 292%, 1 731%, 141%, 2 076%. For root samples, the Cd, Pb, Cu and Zn concentrations increased to 0.52 mg/kg, 4.36 mg/kg, 10.87 mg/kg, and 98.12 mg/kg and the increase rates were 1 034%, 140%, 29%, and 181%, respectively. The phytoextraction efficiency of the Bidens pilosa was significantly higher than that of control group. The removal efficiency of Cd, Pb, Cu and Zn in soil increased to 26%, 72%, 27%, and 79% with the EK applied. In addition, the mechanism of HM migration,extraction and enrichment in Bidens pilosa under the EK condition was discussed.     

煤矸石山不同植被恢复模式对土壤养分的影响——以山西省河东矿区1号煤矸石山为例

对2009-2011 年山西省河东矿区不同植被恢复模式下土壤养分进行了检测分析,并对其环境影响因子进行了研究.结果显示：(1) 随着矸石山植被恢复年限的增加,煤矸石山地温显著降低,植物多样性增加,盖度和生物量不同程度提高.(2) 经过3 年植被恢复的矸石山土壤速效磷和速效钾的改良效果达到全国土壤普查3 级水平;恢复土壤碱解氮和有机质含量为11.94 mg·kg^-1和7.69 g·kg^-1,改良效果不显著.紫穗槐模式对土壤速效磷的改良效果较好;紫穗槐-高羊茅-紫花苜蓿模式有利于碱解氮的积累;高羊茅-紫花苜蓿模式对速效钾和有机质的改良效果最佳.(3) 矸石山坡度和地温与土壤养分呈显著负相关;紫花苜蓿盖度与碱解氮、速效钾和有机质含量呈显著正相关;植被平均生物量和高羊茅盖度的提高有助于土壤养分的改良效果.煤矸石山植被恢复宜采取以草开路,在生态环境条件有所改善基础上,走草、灌、乔相结合的构建模式.     

我国部分地区煤及煤矸石中汞的分布特征

采用原子荧光光谱仪测定了陕西、山西、云南、山东以及河南等地一些煤、电厂炉渣、飞灰等样品中汞元素的质量分数。检出限为0.01×10-6。除淮南地区的个别样品外,多数样品中汞的质量分数处于世界多数煤和中国多数煤中Hg质量分数范围内,少数高于世界煤炭汞质量分数的平均值(0.02×10-6~1.0×10-6)。不同地层间、不同类型样品间汞的质量分数有较大差别:上石盒子组中的>山西组中的>太原组中的;飞灰中的汞质量分数明显大于炉渣中的汞质量分数;褐煤中的汞质量分数高于无烟煤中的。      

系列富硅铝矿石水热晶化法合成纳米莫来石复相粉体的研究

分别以粉煤灰、煤矸石、红柱石千枚岩、油页岩渣等富硅铝矿石为原料,经过除杂、煅烧活化后,利用水热晶化法制备出纳米莫来石复相粉体。采用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、能量色散X射线荧光光谱分析(EDX)和选区电子衍射(SAED)等手段研究了复相粉体的物相组成与显微结构,并用魔角旋转核磁(MAS~NMR)分析水热晶化反应机理。结果表明:经过一定温度煅烧活化后,当NaOH溶液浓度为2~3 mol/L、搅拌温度80~90℃、恒温3 h、液固比为10 mL/g时,上述四种原料均可制得以莫来石为主晶相的纳米复相粉体,其中以煤矸石、红柱石千枚岩、油页岩渣为原料制备的晶体均为结晶良好的柱状晶,平均长度分别为50、300和150 nm,平均长径比分别为4、3.5和3.75;以粉煤灰为原料制备的晶体主要呈现棒状、针状和纤维状,其棒状晶长度约30~80 nm、直径约4.5~30 nm。     

兖州煤田煤矸石中敏感性元素动态淋滤特征及环境效应评价

煤矸石是煤炭资源开发过程中产生的大宗固体废弃物,其长期露天堆放会对环境造成一定的污染。为探究煤矸石在自然条件下降水淋滤过程中敏感性元素的淋出特征,选取山东省主要煤炭生产基地——兖州煤田某典型煤矿的煤矸石作为研究对象,模拟自然降雨条件下动态淋滤试验对煤矸石中的9种敏感性元素淋出特征进行了研究。结果表明:淋出液的pH值均偏碱性,介于9.3~9.8,且随着淋滤次数的增加逐渐增高并趋于稳定。F,As元素具有较强的淋出活性,其淋出率分别为2.60%,1.06%,且全部时间段的淋出液浓度均超出了地下水质量标准Ⅳ类水限值。Cd,Cr,Cu,Hg,Ni,Pb,Zn元素的淋出率均低于0.05%,反映了相对较弱的淋出活性,其各时间段的淋出液浓度均满足地下水质量标准Ⅲ类水的要求。9种敏感性指标均呈现有间歇性快速释放规律,且随淋滤时间的延长,各元素在淋滤后期逐步稳定慢速释放。大量露天堆放以及直接充填于采煤塌陷区内的煤矸石对周边水环境的长期污染效应不容忽视。     

The effects of coal gangue and fly ash on the hydraulic properties and water content distribution in reconstructed soil profiles of coal‐mined land with a high groundwater table

Soil water systems have been severely degraded in coal‐mined and subsiding land, where a shallow groundwater table is also present. The present paper discussed the effects of fly ash (FA) and coal gangue (CG) as filling materials on the hydraulic properties and water content distribution in a profile for the purpose of rehabilitating subsided lands. The saturated water content, water characteristic curve, and water diffusivity of local soil, FA, CG, and a mixture of FA and CG (“mixed filling”) were characterized. A column experiment was conducted to investigate the changes of water content in profiles reconstructed from the combination of soil and filling materials, including soil only, FA, CG, and a mixture of FA and CG, which were used to fill the lower part of the reconstructed profile. The mixture of FA and CG was found to possess similar hydraulic properties to those of the soil, particularly high water‐holding capacity and permeability. Moreover, the volumetric water contents in the whole profile containing the mixture of FA and CG were consistent with those of the profile reconstructed with soil only. As a result, it is recommended to adopt the mixture of FA and CG for reconstructing the lower profile of the land to alleviate or rehabilitate subsided land in coal mines.     

三维激光扫描技术在煤矸石山复垦中的应用

针对煤矸石山复垦过程中可能出现的各种量化问题,以某矿一座小型煤矸石山为例,利用三维激光扫描仪进行扫描测量,并用相关软件对点云进行一系列处理,解决了复垦过程中未知的土石方量、覆土量和植被量问题。同时对文中方法进行精度对比及分析。实验证明,把三维激光扫描技术应用于煤矸石山复垦中,不仅加快了复垦工作的进度,还大大节省了时间和人力成本。     

海孜煤矿煤矸石充填复垦技术研究

以海孜煤矿为例,针对长期开采造成的大面积塌陷区,以及煤矸石利用率低,大量压占土地现象严重等问题,根据因地制宜的原则,对选定的四个项目区进行煤矸石充填复垦工程.工程结束后,将恢复建筑用地30.55hm2,耕地367.44hm2,同时消耗煤矸石3153t,既解决了土地利用紧张的问题,又有利用保护环境,防治环境污染,具有显著...     

两种复垦地土壤理化性质的研究

利用粉煤灰和煤矸石作为充填基质充填沉陷地覆土造地是治理采煤塌陷区的重要方法之一.为研究煤矸石、粉煤灰充填复垦方式对土壤理化性质的影响,本文以淮南上窑粉煤灰场复垦地和新庄孜矿煤矸石充填复垦地为研究对象,分别对粉煤灰复垦地土壤样品、煤矸石复垦地土壤样品和对照地块土壤样品的土壤pH值、土壤含水量、土壤有机质、水解氮、速效磷、有效钾含量、冬小麦产量等指标监测分析.结果表明,复垦土壤pH值大于对照土壤样品,粉煤灰充填复垦土壤呈强碱性,煤矸石充填复垦土壤pH值接近对照土壤;粉煤灰充填复垦地粉煤灰层土壤含水量明显大于对照土壤样品,煤矸石充填复垦地煤矸石层土壤含水量明显低于对照土壤样品;复垦土壤有机质、水解氮、速效磷、有效钾含量、冬小麦产量低于对照土壤样品.粉煤灰充填复垦土壤水解氮含量、有效钾含量低于煤矸石充填复垦土壤,速效磷含量高于煤矸石充填复垦土壤.     

Research on Potential Fertilization of Coal Gangue in the Weibei Coalfield, China

Based on the systematic analysis of the coal gangue in Weibei Coalfield, such as petrologic characteristics, chemical composition, nutrient elements, deleterious elements, and the transformation, and compared with the soil element content background values of Loess Plateau and national harmful materials controlling standards, we conclude that the coal gangue in the Weibei Coalfield has huge potential to be used as clay fertilizer.