Barman Pranab Jyoti, Kartha Suresh A, Pradhan Bulu
Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
Environ Sci Pollut Res Int. 2015 May;22(9):6619-33. doi: 10.1007/s11356-014-3844-1. Epub 2014 Nov 21.
An empirical approach is made in this investigation to predict the leached concentrations of sodium (Na), calcium (Ca), and potassium (K) in the effluents from a landfill site. Water at certain predetermined inflow filling rate is applied to a specific ponding depth, at the top of an experimental column filled with landfill refuse soil at the top (upper layer) and normal local soil at the bottom (base layer). The water infiltrates into the upper layer soil, percolates through the pores in upper and base layers, and in the process leaches the nutrients from the soils that are collected at the bottom of the column. The experimentations were for different combinations of heights of upper and base layer soils, water ponding depth, and inflow filling rates. The nutrient concentrations in the outflow leachates are measured using flame photometer. The observations showed mixed responses of leaching and trapping of nutrients in the soil layers for the various combinations. The experimental observations also inferred that the nutrient leaching is more for cases involving higher ponding depths and higher inflow filling rates. Empirical relationships with respect to the geometrical parameters, to predict the leached concentrations of Na, Ca, and K, are developed from the experimental observations using nonlinear least squares regressive techniques. Exponential equations gave the best empirical fit among various nonlinear relations in the regression technique. The empirical models also predicted well for each subcategory of independent variables that are substantiated by high correlation coefficients.
本研究采用实证方法预测垃圾填埋场渗滤液中钠（Na）、钙（Ca）和钾（K）的淋溶浓度。以一定的预定入流填充率向特定的积水深度供水，该积水深度位于顶部填充垃圾填埋场土壤（上层）和底部填充当地普通土壤（基层）的实验柱顶部。水渗入上层土壤，通过上层和基层的孔隙渗透，并在此过程中从柱底部收集的土壤中淋溶出养分。实验针对上层和基层土壤高度、积水深度和入流填充率的不同组合进行。使用火焰光度计测量流出渗滤液中的养分浓度。观察结果表明，对于各种组合，土壤层中养分的淋溶和截留呈现混合响应。实验观察还推断，在积水深度较高和入流填充率较高的情况下，养分淋溶更为明显。利用非线性最小二乘回归技术，根据实验观察结果建立了关于几何参数的经验关系，以预测Na、Ca和K的淋溶浓度。在回归技术的各种非线性关系中，指数方程给出了最佳的经验拟合。经验模型对由高相关系数证实的每个自变量子类别也有良好的预测。
