填埋场渗滤液腐殖酸随填埋龄的变化特性及模型研究

以福建省12个不同填埋场渗滤液作为研究对象,分析了不同填埋龄渗滤液中腐殖酸的性质随填埋龄的变化关系.结果表明,渗滤液中富里酸(FA)浓度和比例都高于胡敏酸(HA),且HA、FA和腐殖酸(HS)的浓度都随着填埋龄的增加呈先上升后下降,HA所占比例随填埋龄的增加呈先上升后下降的趋势,而FA和HS则是先上升,后呈波动变化.HA、FA的E280、E300/E400和E465/E665的分析结果表明HA较FA有更多的芳环结构,更大的分子量和较高腐殖化程度;随着填埋龄的增加,HA的腐殖化程度呈下降趋势,而FA则呈上升趋势;HA和FA的E300/E400和E465/E665随填埋龄的增加并未有明显的变化趋势.根据有机物降解动力学原理建立模型,分别对HA、FA和HS的浓度和填埋龄的变化关系进行拟合,结果表明模型的模拟值和实测值具有较好的一致性,HA、FA和HS模拟值和实测值的相关系数R2分别为0.820、0.932和0.946.表明该模型能有效模拟和预测腐殖酸随填埋龄的浓度变化关系.

Variation Characteristics and Mathematical Model of Humic Substances in Landfill Leachates with Different Landfill Ages

The influence of municipal landfill age on the characteristics of humic substances in leachate on the basis of investigating 12 different kinds of leachates from landfills in Fujian province is presented in this study. It was shown that the concentration and percentage of fulvic acid (FA) were obviously higher than those of humic acid (HA). As the landfill age increased, the concentrations of HA, FA and humic substances (HS) increased, moreover, the percentage of HA first increased and then decreased. While the percentages of FA and HS first increased and then fluctuated with the landfill age. The UV-Vis analytical results of HA and FA through E₂₈₀, E₃₀₀/E₄₀₀ and E₄₆₅/E₆₆₅ revealed that HA had a relatively higher content of aromatic compounds and higher molecular weight than FA. The humification of FA had a tendency to increase as the landfill age increased, while HA had opposite result. The E₃₀₀/E₄₀₀ and E₄₆₅/E₆₆₅ of HA and FA fluctuated with increasing landfill age. A mathematical model simulating the concentration of humic substances varied with the landfill age was presented and demonstrated based on degradation kinetics. The simulated results were close to the measured values with a correlation coefficient R² of 0.820, 0.932 and 0.946, respectively, indicating that the concentrations of HA, FA and HS could be accurately forecasted.