Smidt Ena, Böhm Katharina, Tintner Johannes
Department of Water, Atmosphere and Environment, Institute of Waste Management, University of Natural Resources and Applied Life Sciences, Vienna, Muthgasse 107, 1190 Vienna, Austria.
J Environ Monit. 2011 Feb;13(2):362-9. doi: 10.1039/c0em00265h. Epub 2010 Dec 6.
Abandoned landfills and dumps, where untreated waste materials were deposited in the past, are a main anthropogenic source of relevant gaseous emissions. The determination of stability is a crucial target in the context of landfill risk assessment. FTIR spectroscopy and simultaneous thermal analysis in association with multivariate statistical methods were applied to landfill materials in order to get information on the kind of waste and its reactivity. The spectral and thermal patterns are fingerprints of the material. Industrial waste and the material from a 5-year-old reactor landfill were distinguished from the defined classes of mechanically-biologically treated ("MBT") waste and 30 to 40-year-old stable landfills containing municipal solid waste and construction waste ("LF") by a classification model based on soft independent modeling of class analogy (SIMCA). Degradation experiments were carried out with the fresh material originating from one MBT plant that was subjected to aerobic and anaerobic conditions in lab-scale reactors. These samples were compared to samples of one reactor landfill and to the landfill fraction from the MBT plant to demonstrate the efficiency of the biological pretreatment before final disposal. Prediction models that are based on spectral or thermal characteristics and the corresponding reference analyses were calculated by means of a partial least squares regression (PLS-R). The developed models of the biological oxygen demand (BOD) and the dissolved organic carbon (DOC) were based on spectral data, the models of the total organic carbon (TOC) and total nitrogen (TN) were based on thermal data (heat flow profiles and mass spectra of combustion gases). Preliminary results are discussed. The enthalpy of the materials decreases with progressing mineralization, whereas the enthalpy of the remaining organic matter increases. The ratio of the enthalpies was used as an indicator of stability. Selected samples comprising old landfills, a recent reactor landfill, MBT landfills and MBT materials were classified according to the calculated ratios.
废弃的垃圾填埋场和垃圾倾卸场，过去曾用于堆放未经处理的废料，是相关气体排放的主要人为来源。在垃圾填埋场风险评估中，确定稳定性是一个关键目标。傅里叶变换红外光谱（FTIR）和同步热分析结合多元统计方法被应用于垃圾填埋场材料，以获取有关废物种类及其反应性的信息。光谱和热模式是材料的指纹图谱。基于类软独立建模（SIMCA）的分类模型，将工业废料以及来自一个5年历史的反应性垃圾填埋场的材料，与经过机械 - 生物处理（“MBT”）的特定类别废料以及含有城市固体废物和建筑垃圾的30至40年历史的稳定垃圾填埋场（“LF”）区分开来。使用来自一个MBT工厂的新鲜材料在实验室规模的反应器中进行有氧和厌氧条件下的降解实验。将这些样品与一个反应性垃圾填埋场的样品以及MBT工厂的垃圾填埋部分样品进行比较，以证明最终处置前生物预处理的效率。基于光谱或热特性以及相应参考分析的预测模型通过偏最小二乘回归（PLS - R）计算得出。所建立的生物需氧量（BOD）和溶解有机碳（DOC）模型基于光谱数据，总有机碳（TOC）和总氮（TN）模型基于热数据（热流曲线和燃烧气体质谱）。对初步结果进行了讨论。随着矿化作用的进行，材料的焓降低，而剩余有机物的焓增加。焓的比率被用作稳定性的指标。根据计算出的比率对包括旧垃圾填埋场、近期反应性垃圾填埋场、MBT垃圾填埋场和MBT材料的选定样品进行分类。
