Analysis of diffusion-adsorption equivalency of landfill liner systems for organic contaminants

The equivalence between multilayered barriers regarding diffusion and adsorption is analyzed by means of an analytical method. The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil. Five different liner systems were compared in terms of solute breakthrough time. The results of the analysis show that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner (CCL) can be 3-4 orders of magnitude greater than the breakthrough time for a geosynthetic clay liner (GCL) composite liner. The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry's coefficient. The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives, for the specific conditions examined. If the distribution coefficient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds, the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4. As far as diffusive and adsorption contaminant transport are concerned, GM or GCL is less effective than CCL.     

考虑非线性吸附时溶质在有限厚度粘土中的一维扩散解

在采用非线性分段式吸附等温模式的基础上,建立了溶质在粘土中的一维扩散模型,在考虑有限厚度边界及土中溶质背景浓度的条件下得到了相应的解.模型引入了移动边界以说明当溶质在粘土孔隙水中的浓度达到某一较高值后,阻滞因子将发生显著变化.算例分析表明,该模型和考虑经典非线性吸附等温线得到的结果相差不大,这进一步说明了该模型的合理性.考虑非线性吸附效应对溶质迁移有重要影响.在较高溶质浓度下采用线性吸附等温模式会得到偏不安全的结果.该解相对较简单,并可用于验证各种数值模型、拟合试验数据等.     

Time Domain Reflectometry for Water Content Measurement of Municipal Solid Waste

Water content measurement of municipal solid waste (MSW) is critical to water balance analysis of landfill, leachate collection and recirculation, and acceleration of MSW degradation. Time domain reflectometry (TDR) is commonly applied to soils for the measurement of water content. Application of TDR methods for moisture measurement in MSW is difficult, because MSW is a heterogeneous and highly conductive material. This study investigated the application of TDR surface reflection method for the determination of apparent dielectric constant and water content of MSW. A series of experiments were conducted to study the dielectric properties of MSW and its main components such as paper, plastic, and organics. Results indicate that the effect of waste material type seems to be negligible on the measurement of water content. TDR technique can effectively measure the intrinsic water of organics in the absence of significant bound water effects. Results of dielectric constant by surface reflection method gave similar accuracy as the conventional travel time analysis for waste materials with low electrical conductivities. In addition, surface reflection method provides higher accuracy for waste materials with high electrical conductivities than travel time analysis. This research provides experimental basis for the use of TDR surface reflection method in landfills.     

2013年11月23日吉林松原地震强地面运动三要素特征分析

收集整理了2013年11月23日吉林省松原市前郭尔罗斯蒙古族自治县Ms5.8和Ms5.0地震的地表强震动记录,进行了常规的处理,剔除掉了异常的记录.通过分析地震动三要素特征,首先获得了较为可靠的PGA和PGV幅值,拟合出PGA与PGV之间的关系;其次以较常用的Significant持时、Bracketed持时作为研究对象,进行回归分析,探讨了松原地区地震动持时与距离的相关性;最后计算了松原地震中典型的幅值较大的记录5％阻尼比的反应谱,并与我国《建筑抗震设计规范》(GB50011-2010)中的设计谱进行了比较.     

烧结烟气脱硫渣的综合利用

本文通过对烧结烟气脱硫副产物—脱硫渣的特性分析,从脱硫渣用做钢渣粉激发剂和水泥缓凝剂两方面开展研究,得出脱硫渣用做钢渣粉激发剂和水泥缓凝剂的最佳掺加比例。脱硫渣用做钢渣粉激发剂和水泥缓凝剂可以提高钢渣粉、水泥的性能,同时也实现了烧结烟气脱硫渣"零排放"和资源化利用。     

浅谈烟气脱硫渣的利用

介绍了国内外脱硫渣综合利用的情况，分析了国内脱硫渣利用的形式。对脱硫今后的研究方向进行了展望。     

Analysis of di usion-adsorption equivalency of landfill liner systems for organic contaminants

The equivalence between multilayered barriers regarding di usion and adsorption was studied. The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil. Five di erent liner systems were compared in terms of solute breakthrough time. The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner (CCL) could be 3–4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner (GCL) composite liner. The GM/GCL and GM/CCL composite liner systems provide a better di usion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their di erent Henry’s coe cient. The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives, for the specific conditions examined. If the distribution coe cient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds, the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9–2.4. As far as di usive and adsorption contaminant transport are concerned, GM or GCL is less e ective than CCL.