Kumar Dinesh, Jonnalagadda Sreeram, Jain Pradeep, Gawande Nitin A, Townsend Timothy G, Reinhart Debra R
Environmental Engineering Sciences, University of Florida, P.O. Box 116450, Gainesville, FL 32611-6450, USA.
Waste Manag. 2009 May;29(5):1547-57. doi: 10.1016/j.wasman.2008.10.020. Epub 2009 Feb 28.
The ability of resistance-based sensors to measure in situ waste moisture content in a landfill was examined. One hundred and thirty-five resistance-based sensors were installed in a leachate recirculation well field at a bioreactor landfill in Florida, US. The performance of these sensors was studied for a period of over 6 years. The sensors were found to respond to an increase in moisture resulting from leachate recirculation. It was observed that 78% of sensors worked successfully in the field during the study period. The initial spatial average moisture content determined by the sensor readings (using a laboratory-derived calibration) was 42.8% compared to 23% from gravimetric readings. Eighteen sensors (13%) showed that they were saturated before liquid addition, and no change in moisture content was observed in these sensors during the study period. Laboratory-derived calibration methods resulted in an over-estimation of moisture content. An alternate field-calibration method, where wetted sensor output was assumed equal to the average of gravimetric measurements for wet samples, was evaluated. The final spatial average moisture contents were 64.2% and 44.4% for the laboratory-derived and field-derived calibration methodologies, respectively, compared to 45% measured gravimetrically from excavated waste samples. When moisture content was determined using a mass balance approach, the result was 34.6%. The results suggest that when appropriately calibrated, resistivity-based sensors can be used to obtain a reasonably accurate estimate of local moisture content. However, caution should be taken to extend the moisture content values that are representative of waste surrounding the sensors to estimate the overall moisture content on the landfill-wide scale.
研究了基于电阻的传感器测量垃圾填埋场原位废物含水量的能力。135个基于电阻的传感器安装在美国佛罗里达州一个生物反应器垃圾填埋场的渗滤液回灌井场中。对这些传感器的性能进行了为期6年多的研究。发现这些传感器对渗滤液回灌导致的水分增加有响应。观察到在研究期间，78%的传感器在现场成功运行。由传感器读数（使用实验室得出的校准方法）确定的初始空间平均含水量为42.8%，相比之下，重量法读数得出的含水量为23%。18个传感器（13%）显示在添加液体之前它们已饱和，并且在研究期间这些传感器的含水量没有变化。实验室得出的校准方法导致对含水量的高估。评估了一种替代的现场校准方法，即假定湿润传感器的输出等于湿样品重量测量的平均值。对于实验室得出的校准方法和现场得出的校准方法，最终的空间平均含水量分别为64.2%和44.4%，相比之下，从挖掘出的废物样品重量法测量得出的含水量为45%。当使用质量平衡方法确定含水量时，结果为34.6%。结果表明，经过适当校准时，基于电阻率的传感器可用于获得当地含水量的合理准确估计值。然而，在将代表传感器周围废物的含水量值扩展以估计整个垃圾填埋场规模的总体含水量时应谨慎。
