| 摘要: | 近年來，廢水偷排案件層出不窮，其中不乏含有銅、鎳等重金屬的廢水，導致環境嚴重污染，目前常見銅、鎳之檢測方法為感應耦合電漿光學發射光譜儀(ICP-OES)、或原子吸收光譜儀之檢測方式(AAS)，分析過程不僅耗時耗能且產生大量實驗室廢液，如遇較高濃度之樣品時，容易造成儀器污染或使用高倍率稀釋導致數據偏差。
本研究探討X射線螢光光譜儀(XRF)，是否具備液體重金屬之檢測分析能力，目前XRF主要分為能量散射式X射線螢光分析儀(Energy Dispersive X-Ray Fluorescence, ED-XRF)、及波長散射式X射線螢光分析儀(Wavelength Dispersive X-Ray Fluorescence, WD-XRF)，常應用於土壤、結構性分析、及有害物質限用指令(The Restriction of the use of certain Hazardous Substances in electrical and electronic equipment, RoHS)等固體樣品之分析，如可應用於含重金屬液體樣品時，不僅可節省大量分析時間，且減少實驗成本與廢液之產生，更符合綠色化學之方針。
為評估ED-XRF對液態樣品中銅、鎳重金屬的分析能力，本研究選用穩定性高、檢測能力佳之桌上型ED-XRF設備，並收集多家光電業、半導體業、傳產業等實廠製程廢液，進行ED-XRF與ICP-OES之銅、鎳數據比較。
結果顯示，兩種設備顯示銅、鎳濃度皆具良好相關性(R2 > 0.9)，樣品直接稀釋上機與經過酸消化(pH>5樣品)之數據表現也具有良好相關性(R2 > 0.9)，然而，在酸消化過程中若產生沉澱或懸浮物，則易導致濃度低估。在ED-XRF分析秒數上，分別在60秒與120秒的分析時間下，銅、鎳分析結果皆有良好相關性(R2 > 0.9)，即60秒可分析銅、鎳元素之含量。另外比較兩種設備之檢測成本、碳排放、廢液產生量與檢測效率，ED-XRF皆具有顯著優勢。;In recent years, incidents of illegal wastewater discharge have been frequent, often involving wastewater containing heavy metals such as copper and nickel, leading to severe environmental pollution. The commonly used methods for detecting copper and nickel are Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Atomic Absorption Spectroscopy (AAS). These analytical processes are not only time-consuming and energy-intensive but also generate substantial amounts of laboratory waste. Moreover, high-concentration samples can easily contaminate the instruments or require high dilution ratios, resulting in data inaccuracies.
This study investigates whether X-ray Fluorescence Spectrometry (XRF) can be utilized for the detection and analysis of heavy metals in liquid samples. Currently, XRF is primarily divided into Energy Dispersive X-Ray Fluorescence (ED-XRF) and Wavelength Dispersive X-Ray Fluorescence (WD-XRF). These methods are commonly applied to the analysis of solid samples such as soil, structural materials, and for compliance with the Restriction of Hazardous Substances Directive (RoHS). If applicable to liquid samples containing heavy metals, XRF could significantly reduce analysis time, lower experimental costs, and minimize the generation of waste, aligning well with the principles of green chemistry.
To evaluate the capability of ED-XRF in analyzing copper and nickel heavy metals in liquid samples, this study selected a highly stable and well-performing benchtop ED-XRF device. Wastewater samples from real industrial processes in the optoelectronics, semiconductor, and traditional manufacturing industries were collected. The copper and nickel data obtained from ED-XRF were compared with those from ICP-OES.
The results showed that both devices exhibited a strong correlation in copper and nickel concentrations (R² > 0.9). There was also a good correlation (R² > 0.9) between direct dilution samples and those subjected to acid digestion (for samples with pH > 5). However, precipitation or suspended particles formed during the acid digestion process could lead to an underestimation of concentrations. In terms of ED-XRF analysis time, both 60-second and 120-second analyses showed strong correlation (R² > 0.9) for copper and nickel, indicating that 60 seconds is sufficient to analyze the content of these elements. Additionally, when comparing the detection cost, carbon emissions, wastewater generation, and detection efficiency of the two devices, ED-XRF demonstrated significant advantages. |
