利用太赫兹光谱技术进行了土壤中重金属铅含量检测研究, 太赫兹光谱是一种拥有多种独特性质的新型安全检测技术, 前期实验结果证明该研究具有一定可行性。制备了不同浓度的含铅污染土壤样品, 研究并确定了压片法制备参数, 然后在首都师范大学太赫兹实验室开展了样品测量实验, 获取了有效数据。分别采用偏最小二乘和区间偏最小二乘法对太赫兹全谱数据进行了建模和预测, 结果表明经优化的预测结果相关系数达到0.81, 证实了该方法可行。借助于该检测手段, 可以得到农田的重金属铅污染分布图, 然后根据污染图进行污染治理和农田土壤有效管理, 从而提高农田的生产能力。为精准农业中农田重金属污染快速检测、实现农业可持续发展提供参考。

An exploration on heavy metal Pb2+ detection method was presented based on Terahertz(THz) Spectroscopy, which is rapid and maybe portable and low cost for future in-field applications. THz is a brand new and safe technology with many unique features. It showed feasibility for heavy metal detections in soil according to former experiments. A series of experiment were carried out in this study. Soil samples with predefined concentration levels of Pb2+ ions were carefully prepared. Pressed-slice method was used for the spectra measurement and sample making parameters were determined. The absorption spectra were collected with a THz spectroscopic system in Capital Normal University. Multivariate statistical methods were studied and used to analyze the collected data and establish predication model for Pb2+ concentrations. Calibration and prediction models were established based on Partial-least-square(PLS) and Interval Partial-least-square(i-PLS) methods using the full THz spectrum and the selected THz wavebands respectively. The results show that the optimized models are able to predict soil heavy metal Pb2+ content with a correlation coefficient of 0.81. The method of using THz technology for soil heavy metal Pb2+ detection is feasible. With the detection results, it can be found the heavy metal Pb2+ pollution spatial distribution information of the soil in-field and get the "pollution map". Specific measures shall be taken based on the "pollution map" to manage the soil to improve the farmland productivity. This study will provide a reference for heavy metals pollution detection solutions for precision farming and sustainable agriculture development.